e025d3860b
1227 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Vladimir Davydov
|
c4159a75b6 |
mm: memcontrol: only mark charged pages with PageKmemcg
To distinguish non-slab pages charged to kmemcg we mark them PageKmemcg,
which sets page->_mapcount to -512. Currently, we set/clear PageKmemcg
in __alloc_pages_nodemask()/free_pages_prepare() for any page allocated
with __GFP_ACCOUNT, including those that aren't actually charged to any
cgroup, i.e. allocated from the root cgroup context. To avoid overhead
in case cgroups are not used, we only do that if memcg_kmem_enabled() is
true. The latter is set iff there are kmem-enabled memory cgroups
(online or offline). The root cgroup is not considered kmem-enabled.
As a result, if a page is allocated with __GFP_ACCOUNT for the root
cgroup when there are kmem-enabled memory cgroups and is freed after all
kmem-enabled memory cgroups were removed, e.g.
# no memory cgroups has been created yet, create one
mkdir /sys/fs/cgroup/memory/test
# run something allocating pages with __GFP_ACCOUNT, e.g.
# a program using pipe
dmesg | tail
# remove the memory cgroup
rmdir /sys/fs/cgroup/memory/test
we'll get bad page state bug complaining about page->_mapcount != -1:
BUG: Bad page state in process swapper/0 pfn:1fd945c
page:ffffea007f651700 count:0 mapcount:-511 mapping: (null) index:0x0
flags: 0x1000000000000000()
To avoid that, let's mark with PageKmemcg only those pages that are
actually charged to and hence pin a non-root memory cgroup.
Fixes:
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Mel Gorman
|
b4911ea2bc |
mm: initialise per_cpu_nodestats for all online pgdats at boot
Paul Mackerras and Reza Arbab reported that machines with memoryless nodes fail when vmstats are refreshed. Paul reported an oops as follows Unable to handle kernel paging request for data at address 0xff7a10000 Faulting instruction address: 0xc000000000270cd0 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-kvm+ #118 task: c000000ff0680010 task.stack: c000000ff0704000 NIP: c000000000270cd0 LR: c000000000270ce8 CTR: 0000000000000000 REGS: c000000ff0707900 TRAP: 0300 Not tainted (4.7.0-kvm+) MSR: 9000000102009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]> CR: 846b6824 XER: 20000000 CFAR: c000000000008768 DAR: 0000000ff7a10000 DSISR: 42000000 SOFTE: 1 NIP refresh_zone_stat_thresholds+0x80/0x240 LR refresh_zone_stat_thresholds+0x98/0x240 Call Trace: refresh_zone_stat_thresholds+0xb8/0x240 (unreliable) Both supplied potential fixes but one potentially misses checks and another had redundant initialisations. This version initialises per_cpu_nodestats on a per-pgdat basis instead of on a per-zone basis. Link: http://lkml.kernel.org/r/20160804092404.GI2799@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Paul Mackerras <paulus@ozlabs.org> Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Fabian Frederick
|
bd721ea73e |
treewide: replace obsolete _refok by __ref
There was only one use of __initdata_refok and __exit_refok
__init_refok was used 46 times against 82 for __ref.
Those definitions are obsolete since commit
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Vlastimil Babka
|
c3486f5376 |
mm, compaction: simplify contended compaction handling
Async compaction detects contention either due to failing trylock on
zone->lock or lru_lock, or by need_resched(). Since
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Vlastimil Babka
|
a5508cd83f |
mm, compaction: introduce direct compaction priority
In the context of direct compaction, for some types of allocations we would like the compaction to either succeed or definitely fail while trying as hard as possible. Current async/sync_light migration mode is insufficient, as there are heuristics such as caching scanner positions, marking pageblocks as unsuitable or deferring compaction for a zone. At least the final compaction attempt should be able to override these heuristics. To communicate how hard compaction should try, we replace migration mode with a new enum compact_priority and change the relevant function signatures. In compact_zone_order() where struct compact_control is constructed, the priority is mapped to suitable control flags. This patch itself has no functional change, as the current priority levels are mapped back to the same migration modes as before. Expanding them will be done next. Note that !CONFIG_COMPACTION variant of try_to_compact_pages() is removed, as the only caller exists under CONFIG_COMPACTION. Link: http://lkml.kernel.org/r/20160721073614.24395-8-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
|
2516035499 |
mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations
After the previous patch, we can distinguish costly allocations that
should be really lightweight, such as THP page faults, with
__GFP_NORETRY. This means we don't need to recognize khugepaged
allocations via PF_KTHREAD anymore. We can also change THP page faults
in areas where madvise(MADV_HUGEPAGE) was used to try as hard as
khugepaged, as the process has indicated that it benefits from THP's and
is willing to pay some initial latency costs.
We can also make the flags handling less cryptic by distinguishing
GFP_TRANSHUGE_LIGHT (no reclaim at all, default mode in page fault) from
GFP_TRANSHUGE (only direct reclaim, khugepaged default). Adding
__GFP_NORETRY or __GFP_KSWAPD_RECLAIM is done where needed.
The patch effectively changes the current GFP_TRANSHUGE users as
follows:
* get_huge_zero_page() - the zero page lifetime should be relatively
long and it's shared by multiple users, so it's worth spending some
effort on it. We use GFP_TRANSHUGE, and __GFP_NORETRY is not added.
This also restores direct reclaim to this allocation, which was
unintentionally removed by commit e4a49efe4e7e ("mm: thp: set THP defrag
by default to madvise and add a stall-free defrag option")
* alloc_hugepage_khugepaged_gfpmask() - this is khugepaged, so latency
is not an issue. So if khugepaged "defrag" is enabled (the default), do
reclaim via GFP_TRANSHUGE without __GFP_NORETRY. We can remove the
PF_KTHREAD check from page alloc.
As a side-effect, khugepaged will now no longer check if the initial
compaction was deferred or contended. This is OK, as khugepaged sleep
times between collapsion attempts are long enough to prevent noticeable
disruption, so we should allow it to spend some effort.
* migrate_misplaced_transhuge_page() - already was masking out
__GFP_RECLAIM, so just convert to GFP_TRANSHUGE_LIGHT which is
equivalent.
* alloc_hugepage_direct_gfpmask() - vma's with VM_HUGEPAGE (via madvise)
are now allocating without __GFP_NORETRY. Other vma's keep using
__GFP_NORETRY if direct reclaim/compaction is at all allowed (by default
it's allowed only for madvised vma's). The rest is conversion to
GFP_TRANSHUGE(_LIGHT).
[mhocko@suse.com: suggested GFP_TRANSHUGE_LIGHT]
Link: http://lkml.kernel.org/r/20160721073614.24395-7-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Vlastimil Babka
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3eb2771b06 |
mm, page_alloc: make THP-specific decisions more generic
Since THP allocations during page faults can be costly, extra decisions
are employed for them to avoid excessive reclaim and compaction, if the
initial compaction doesn't look promising. The detection has never been
perfect as there is no gfp flag specific to THP allocations. At this
moment it checks the whole combination of flags that makes up
GFP_TRANSHUGE, and hopes that no other users of such combination exist,
or would mind being treated the same way. Extra care is also taken to
separate allocations from khugepaged, where latency doesn't matter that
much.
It is however possible to distinguish these allocations in a simpler and
more reliable way. The key observation is that after the initial
compaction followed by the first iteration of "standard"
reclaim/compaction, both __GFP_NORETRY allocations and costly
allocations without __GFP_REPEAT are declared as failures:
/* Do not loop if specifically requested */
if (gfp_mask & __GFP_NORETRY)
goto nopage;
/*
* Do not retry costly high order allocations unless they are
* __GFP_REPEAT
*/
if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
goto nopage;
This means we can further distinguish allocations that are costly order
*and* additionally include the __GFP_NORETRY flag. As it happens,
GFP_TRANSHUGE allocations do already fall into this category. This will
also allow other costly allocations with similar high-order benefit vs
latency considerations to use this semantic. Furthermore, we can
distinguish THP allocations that should try a bit harder (such as from
khugepageed) by removing __GFP_NORETRY, as will be done in the next
patch.
Link: http://lkml.kernel.org/r/20160721073614.24395-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Vlastimil Babka
|
a8161d1ed6 |
mm, page_alloc: restructure direct compaction handling in slowpath
The retry loop in __alloc_pages_slowpath is supposed to keep trying reclaim and compaction (and OOM), until either the allocation succeeds, or returns with failure. Success here is more probable when reclaim precedes compaction, as certain watermarks have to be met for compaction to even try, and more free pages increase the probability of compaction success. On the other hand, starting with light async compaction (if the watermarks allow it), can be more efficient, especially for smaller orders, if there's enough free memory which is just fragmented. Thus, the current code starts with compaction before reclaim, and to make sure that the last reclaim is always followed by a final compaction, there's another direct compaction call at the end of the loop. This makes the code hard to follow and adds some duplicated handling of migration_mode decisions. It's also somewhat inefficient that even if reclaim or compaction decides not to retry, the final compaction is still attempted. Some gfp flags combination also shortcut these retry decisions by "goto noretry;", making it even harder to follow. This patch attempts to restructure the code with only minimal functional changes. The call to the first compaction and THP-specific checks are now placed above the retry loop, and the "noretry" direct compaction is removed. The initial compaction is additionally restricted only to costly orders, as we can expect smaller orders to be held back by watermarks, and only larger orders to suffer primarily from fragmentation. This better matches the checks in reclaim's shrink_zones(). There are two other smaller functional changes. One is that the upgrade from async migration to light sync migration will always occur after the initial compaction. This is how it has been until recent patch "mm, oom: protect !costly allocations some more", which introduced upgrading the mode based on COMPACT_COMPLETE result, but kept the final compaction always upgraded, which made it even more special. It's better to return to the simpler handling for now, as migration modes will be further modified later in the series. The second change is that once both reclaim and compaction declare it's not worth to retry the reclaim/compact loop, there is no final compaction attempt. As argued above, this is intentional. If that final compaction were to succeed, it would be due to a wrong retry decision, or simply a race with somebody else freeing memory for us. The main outcome of this patch should be simpler code. Logically, the initial compaction without reclaim is the exceptional case to the reclaim/compaction scheme, but prior to the patch, it was the last loop iteration that was exceptional. Now the code matches the logic better. The change also enable the following patches. Link: http://lkml.kernel.org/r/20160721073614.24395-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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23771235bb |
mm, page_alloc: don't retry initial attempt in slowpath
After __alloc_pages_slowpath() sets up new alloc_flags and wakes up kswapd, it first tries get_page_from_freelist() with the new alloc_flags, as it may succeed e.g. due to using min watermark instead of low watermark. It makes sense to to do this attempt before adjusting zonelist based on alloc_flags/gfp_mask, as it's still relatively a fast path if we just wake up kswapd and successfully allocate. This patch therefore moves the initial attempt above the retry label and reorganizes a bit the part below the retry label. We still have to attempt get_page_from_freelist() on each retry, as some allocations cannot do that as part of direct reclaim or compaction, and yet are not allowed to fail (even though they do a WARN_ON_ONCE() and thus should not exist). We can reuse the call meant for ALLOC_NO_WATERMARKS attempt and just set alloc_flags to ALLOC_NO_WATERMARKS if the context allows it. As a side-effect, the attempts from direct reclaim/compaction will also no longer obey watermarks once this is set, but there's little harm in that. Kswapd wakeups are also done on each retry to be safe from potential races resulting in kswapd going to sleep while a process (that may not be able to reclaim by itself) is still looping. Link: http://lkml.kernel.org/r/20160721073614.24395-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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31a6c1909f |
mm, page_alloc: set alloc_flags only once in slowpath
In __alloc_pages_slowpath(), alloc_flags doesn't change after it's initialized, so move the initialization above the retry: label. Also make the comment above the initialization more descriptive. The only exception in the alloc_flags being constant is ALLOC_NO_WATERMARKS, which may change due to TIF_MEMDIE being set on the allocating thread. We can fix this, and make the code simpler and a bit more effective at the same time, by moving the part that determines ALLOC_NO_WATERMARKS from gfp_to_alloc_flags() to gfp_pfmemalloc_allowed(). This means we don't have to mask out ALLOC_NO_WATERMARKS in numerous places in __alloc_pages_slowpath() anymore. The only two tests for the flag can instead call gfp_pfmemalloc_allowed(). Link: http://lkml.kernel.org/r/20160721073614.24395-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andy Lutomirski
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d30dd8be06 |
mm: track NR_KERNEL_STACK in KiB instead of number of stacks
Currently, NR_KERNEL_STACK tracks the number of kernel stacks in a zone. This only makes sense if each kernel stack exists entirely in one zone, and allowing vmapped stacks could break this assumption. Since frv has THREAD_SIZE < PAGE_SIZE, we need to track kernel stack allocations in a unit that divides both THREAD_SIZE and PAGE_SIZE on all architectures. Keep it simple and use KiB. Link: http://lkml.kernel.org/r/083c71e642c5fa5f1b6898902e1b2db7b48940d4.1468523549.git.luto@kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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5a1c84b404 |
mm: remove reclaim and compaction retry approximations
If per-zone LRU accounting is available then there is no point approximating whether reclaim and compaction should retry based on pgdat statistics. This is effectively a revert of "mm, vmstat: remove zone and node double accounting by approximating retries" with the difference that inactive/active stats are still available. This preserves the history of why the approximation was retried and why it had to be reverted to handle OOM kills on 32-bit systems. Link: http://lkml.kernel.org/r/1469110261-7365-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Minchan Kim
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71c799f498 |
mm: add per-zone lru list stat
When I did stress test with hackbench, I got OOM message frequently which didn't ever happen in zone-lru. gfp_mask=0x26004c0(GFP_KERNEL|__GFP_REPEAT|__GFP_NOTRACK), order=0 .. .. __alloc_pages_nodemask+0xe52/0xe60 ? new_slab+0x39c/0x3b0 new_slab+0x39c/0x3b0 ___slab_alloc.constprop.87+0x6da/0x840 ? __alloc_skb+0x3c/0x260 ? _raw_spin_unlock_irq+0x27/0x60 ? trace_hardirqs_on_caller+0xec/0x1b0 ? finish_task_switch+0xa6/0x220 ? poll_select_copy_remaining+0x140/0x140 __slab_alloc.isra.81.constprop.86+0x40/0x6d ? __alloc_skb+0x3c/0x260 kmem_cache_alloc+0x22c/0x260 ? __alloc_skb+0x3c/0x260 __alloc_skb+0x3c/0x260 alloc_skb_with_frags+0x4e/0x1a0 sock_alloc_send_pskb+0x16a/0x1b0 ? wait_for_unix_gc+0x31/0x90 ? alloc_set_pte+0x2ad/0x310 unix_stream_sendmsg+0x28d/0x340 sock_sendmsg+0x2d/0x40 sock_write_iter+0x6c/0xc0 __vfs_write+0xc0/0x120 vfs_write+0x9b/0x1a0 ? __might_fault+0x49/0xa0 SyS_write+0x44/0x90 do_fast_syscall_32+0xa6/0x1e0 sysenter_past_esp+0x45/0x74 Mem-Info: active_anon:104698 inactive_anon:105791 isolated_anon:192 active_file:433 inactive_file:283 isolated_file:22 unevictable:0 dirty:0 writeback:296 unstable:0 slab_reclaimable:6389 slab_unreclaimable:78927 mapped:474 shmem:0 pagetables:101426 bounce:0 free:10518 free_pcp:334 free_cma:0 Node 0 active_anon:418792kB inactive_anon:423164kB active_file:1732kB inactive_file:1132kB unevictable:0kB isolated(anon):768kB isolated(file):88kB mapped:1896kB dirty:0kB writeback:1184kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1478632 all_unreclaimable? yes DMA free:3304kB min:68kB low:84kB high:100kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:4088kB kernel_stack:0kB pagetables:2480kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 809 1965 1965 Normal free:3436kB min:3604kB low:4504kB high:5404kB present:897016kB managed:858460kB mlocked:0kB slab_reclaimable:25556kB slab_unreclaimable:311712kB kernel_stack:164608kB pagetables:30844kB bounce:0kB free_pcp:620kB local_pcp:104kB free_cma:0kB lowmem_reserve[]: 0 0 9247 9247 HighMem free:33808kB min:512kB low:1796kB high:3080kB present:1183736kB managed:1183736kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:372252kB bounce:0kB free_pcp:428kB local_pcp:72kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 DMA: 2*4kB (UM) 2*8kB (UM) 0*16kB 1*32kB (U) 1*64kB (U) 2*128kB (UM) 1*256kB (U) 1*512kB (M) 0*1024kB 1*2048kB (U) 0*4096kB = 3192kB Normal: 33*4kB (MH) 79*8kB (ME) 11*16kB (M) 4*32kB (M) 2*64kB (ME) 2*128kB (EH) 7*256kB (EH) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3244kB HighMem: 2590*4kB (UM) 1568*8kB (UM) 491*16kB (UM) 60*32kB (UM) 6*64kB (M) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 33064kB Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB 25121 total pagecache pages 24160 pages in swap cache Swap cache stats: add 86371, delete 62211, find 42865/60187 Free swap = 4015560kB Total swap = 4192252kB 524186 pages RAM 295934 pages HighMem/MovableOnly 9658 pages reserved 0 pages cma reserved The order-0 allocation for normal zone failed while there are a lot of reclaimable memory(i.e., anonymous memory with free swap). I wanted to analyze the problem but it was hard because we removed per-zone lru stat so I couldn't know how many of anonymous memory there are in normal/dma zone. When we investigate OOM problem, reclaimable memory count is crucial stat to find a problem. Without it, it's hard to parse the OOM message so I believe we should keep it. With per-zone lru stat, gfp_mask=0x26004c0(GFP_KERNEL|__GFP_REPEAT|__GFP_NOTRACK), order=0 Mem-Info: active_anon:101103 inactive_anon:102219 isolated_anon:0 active_file:503 inactive_file:544 isolated_file:0 unevictable:0 dirty:0 writeback:34 unstable:0 slab_reclaimable:6298 slab_unreclaimable:74669 mapped:863 shmem:0 pagetables:100998 bounce:0 free:23573 free_pcp:1861 free_cma:0 Node 0 active_anon:404412kB inactive_anon:409040kB active_file:2012kB inactive_file:2176kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:3452kB dirty:0kB writeback:136kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1320845 all_unreclaimable? yes DMA free:3296kB min:68kB low:84kB high:100kB active_anon:5540kB inactive_anon:0kB active_file:0kB inactive_file:0kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:248kB slab_unreclaimable:2628kB kernel_stack:792kB pagetables:2316kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 809 1965 1965 Normal free:3600kB min:3604kB low:4504kB high:5404kB active_anon:86304kB inactive_anon:0kB active_file:160kB inactive_file:376kB present:897016kB managed:858524kB mlocked:0kB slab_reclaimable:24944kB slab_unreclaimable:296048kB kernel_stack:163832kB pagetables:35892kB bounce:0kB free_pcp:3076kB local_pcp:656kB free_cma:0kB lowmem_reserve[]: 0 0 9247 9247 HighMem free:86156kB min:512kB low:1796kB high:3080kB active_anon:312852kB inactive_anon:410024kB active_file:1924kB inactive_file:2012kB present:1183736kB managed:1183736kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:365784kB bounce:0kB free_pcp:3868kB local_pcp:720kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 DMA: 8*4kB (UM) 8*8kB (UM) 4*16kB (M) 2*32kB (UM) 2*64kB (UM) 1*128kB (M) 3*256kB (UME) 2*512kB (UE) 1*1024kB (E) 0*2048kB 0*4096kB = 3296kB Normal: 240*4kB (UME) 160*8kB (UME) 23*16kB (ME) 3*32kB (UE) 3*64kB (UME) 2*128kB (ME) 1*256kB (U) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3408kB HighMem: 10942*4kB (UM) 3102*8kB (UM) 866*16kB (UM) 76*32kB (UM) 11*64kB (UM) 4*128kB (UM) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 86344kB Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB 54409 total pagecache pages 53215 pages in swap cache Swap cache stats: add 300982, delete 247765, find 157978/226539 Free swap = 3803244kB Total swap = 4192252kB 524186 pages RAM 295934 pages HighMem/MovableOnly 9642 pages reserved 0 pages cma reserved With that, we can see normal zone has a 86M reclaimable memory so we can know something goes wrong(I will fix the problem in next patch) in reclaim. [mgorman@techsingularity.net: rename zone LRU stats in /proc/vmstat] Link: http://lkml.kernel.org/r/20160725072300.GK10438@techsingularity.net Link: http://lkml.kernel.org/r/1469110261-7365-2-git-send-email-mgorman@techsingularity.net Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Minchan Kim
|
33e077bd60 |
mm: show node_pages_scanned per node, not zone
The node_pages_scanned represents the number of scanned pages of node for reclaim so it's pointless to show it as kilobytes. As well, node_pages_scanned is per-node value, not per-zone. This patch changes node_pages_scanned per-zone-killobytes with per-node-count. [minchan@kernel.org: fix node_pages_scanned] Link: http://lkml.kernel.org/r/20160716101431.GA10305@bbox Link: http://lkml.kernel.org/r/1468588165-12461-5-git-send-email-mgorman@techsingularity.net Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
|
bca6759258 |
mm, vmstat: remove zone and node double accounting by approximating retries
The number of LRU pages, dirty pages and writeback pages must be
accounted for on both zones and nodes because of the reclaim retry
logic, compaction retry logic and highmem calculations all depending on
per-zone stats.
Many lowmem allocations are immune from OOM kill due to a check in
__alloc_pages_may_oom for (ac->high_zoneidx < ZONE_NORMAL) since commit
|
||
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Mel Gorman
|
16709d1de1 |
mm: vmstat: replace __count_zone_vm_events with a zone id equivalent
This is partially a preparation patch for more vmstat work but it also has the slight advantage that __count_zid_vm_events is cheaper to calculate than __count_zone_vm_events(). Link: http://lkml.kernel.org/r/1467970510-21195-32-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
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Mel Gorman
|
3b8c0be43c |
mm: page_alloc: cache the last node whose dirty limit is reached
If a page is about to be dirtied then the page allocator attempts to limit the total number of dirty pages that exists in any given zone. The call to node_dirty_ok is expensive so this patch records if the last pgdat examined hit the dirty limits. In some cases, this reduces the number of calls to node_dirty_ok(). Link: http://lkml.kernel.org/r/1467970510-21195-31-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
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Mel Gorman
|
e6cbd7f2ef |
mm, page_alloc: remove fair zone allocation policy
The fair zone allocation policy interleaves allocation requests between zones to avoid an age inversion problem whereby new pages are reclaimed to balance a zone. Reclaim is now node-based so this should no longer be an issue and the fair zone allocation policy is not free. This patch removes it. Link: http://lkml.kernel.org/r/1467970510-21195-30-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
a5f5f91da6 |
mm: convert zone_reclaim to node_reclaim
As reclaim is now per-node based, convert zone_reclaim to be node_reclaim. It is possible that a node will be reclaimed multiple times if it has multiple zones but this is unavoidable without caching all nodes traversed so far. The documentation and interface to userspace is the same from a configuration perspective and will will be similar in behaviour unless the node-local allocation requests were also limited to lower zones. Link: http://lkml.kernel.org/r/1467970510-21195-24-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
52e9f87ae8 |
mm, page_alloc: wake kswapd based on the highest eligible zone
The ac_classzone_idx is used as the basis for waking kswapd and that is based on the preferred zoneref. If the preferred zoneref's first zone is lower than what is available on other nodes, it's possible that kswapd is woken on a zone with only higher, but still eligible, zones. As classzone_idx is strictly adhered to now, it causes a problem because eligible pages are skipped. For example, node 0 has only DMA32 and node 1 has only NORMAL. An allocating context running on node 0 may wake kswapd on node 1 telling it to skip all NORMAL pages. Link: http://lkml.kernel.org/r/1467970510-21195-23-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
e1a556374a |
mm, vmscan: only wakeup kswapd once per node for the requested classzone
kswapd is woken when zones are below the low watermark but the wakeup decision is not taking the classzone into account. Now that reclaim is node-based, it is only required to wake kswapd once per node and only if all zones are unbalanced for the requested classzone. Note that one node might be checked multiple times if the zonelist is ordered by node because there is no cheap way of tracking what nodes have already been visited. For zone-ordering, each node should be checked only once. Link: http://lkml.kernel.org/r/1467970510-21195-22-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
11fb998986 |
mm: move most file-based accounting to the node
There are now a number of accounting oddities such as mapped file pages being accounted for on the node while the total number of file pages are accounted on the zone. This can be coped with to some extent but it's confusing so this patch moves the relevant file-based accounted. Due to throttling logic in the page allocator for reliable OOM detection, it is still necessary to track dirty and writeback pages on a per-zone basis. [mgorman@techsingularity.net: fix NR_ZONE_WRITE_PENDING accounting] Link: http://lkml.kernel.org/r/1468404004-5085-5-git-send-email-mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1467970510-21195-20-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
50658e2e04 |
mm: move page mapped accounting to the node
Reclaim makes decisions based on the number of pages that are mapped but it's mixing node and zone information. Account NR_FILE_MAPPED and NR_ANON_PAGES pages on the node. Link: http://lkml.kernel.org/r/1467970510-21195-18-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
281e37265f |
mm, page_alloc: consider dirtyable memory in terms of nodes
Historically dirty pages were spread among zones but now that LRUs are per-node it is more appropriate to consider dirty pages in a node. Link: http://lkml.kernel.org/r/1467970510-21195-17-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
a9dd0a8310 |
mm, vmscan: make shrink_node decisions more node-centric
Earlier patches focused on having direct reclaim and kswapd use data that is node-centric for reclaiming but shrink_node() itself still uses too much zone information. This patch removes unnecessary zone-based information with the most important decision being whether to continue reclaim or not. Some memcg APIs are adjusted as a result even though memcg itself still uses some zone information. [mgorman@techsingularity.net: optimization] Link: http://lkml.kernel.org/r/1468588165-12461-2-git-send-email-mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1467970510-21195-14-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
38087d9b03 |
mm, vmscan: simplify the logic deciding whether kswapd sleeps
kswapd goes through some complex steps trying to figure out if it should stay awake based on the classzone_idx and the requested order. It is unnecessarily complex and passes in an invalid classzone_idx to balance_pgdat(). What matters most of all is whether a larger order has been requsted and whether kswapd successfully reclaimed at the previous order. This patch irons out the logic to check just that and the end result is less headache inducing. Link: http://lkml.kernel.org/r/1467970510-21195-10-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
599d0c954f |
mm, vmscan: move LRU lists to node
This moves the LRU lists from the zone to the node and related data such as counters, tracing, congestion tracking and writeback tracking. Unfortunately, due to reclaim and compaction retry logic, it is necessary to account for the number of LRU pages on both zone and node logic. Most reclaim logic is based on the node counters but the retry logic uses the zone counters which do not distinguish inactive and active sizes. It would be possible to leave the LRU counters on a per-zone basis but it's a heavier calculation across multiple cache lines that is much more frequent than the retry checks. Other than the LRU counters, this is mostly a mechanical patch but note that it introduces a number of anomalies. For example, the scans are per-zone but using per-node counters. We also mark a node as congested when a zone is congested. This causes weird problems that are fixed later but is easier to review. In the event that there is excessive overhead on 32-bit systems due to the nodes being on LRU then there are two potential solutions 1. Long-term isolation of highmem pages when reclaim is lowmem When pages are skipped, they are immediately added back onto the LRU list. If lowmem reclaim persisted for long periods of time, the same highmem pages get continually scanned. The idea would be that lowmem keeps those pages on a separate list until a reclaim for highmem pages arrives that splices the highmem pages back onto the LRU. It potentially could be implemented similar to the UNEVICTABLE list. That would reduce the skip rate with the potential corner case is that highmem pages have to be scanned and reclaimed to free lowmem slab pages. 2. Linear scan lowmem pages if the initial LRU shrink fails This will break LRU ordering but may be preferable and faster during memory pressure than skipping LRU pages. Link: http://lkml.kernel.org/r/1467970510-21195-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Mel Gorman
|
a52633d8e9 |
mm, vmscan: move lru_lock to the node
Node-based reclaim requires node-based LRUs and locking. This is a preparation patch that just moves the lru_lock to the node so later patches are easier to review. It is a mechanical change but note this patch makes contention worse because the LRU lock is hotter and direct reclaim and kswapd can contend on the same lock even when reclaiming from different zones. Link: http://lkml.kernel.org/r/1467970510-21195-3-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Minchan Kim <minchan@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Mel Gorman
|
75ef718405 |
mm, vmstat: add infrastructure for per-node vmstats
Patchset: "Move LRU page reclaim from zones to nodes v9"
This series moves LRUs from the zones to the node. While this is a
current rebase, the test results were based on mmotm as of June 23rd.
Conceptually, this series is simple but there are a lot of details.
Some of the broad motivations for this are;
1. The residency of a page partially depends on what zone the page was
allocated from. This is partially combatted by the fair zone allocation
policy but that is a partial solution that introduces overhead in the
page allocator paths.
2. Currently, reclaim on node 0 behaves slightly different to node 1. For
example, direct reclaim scans in zonelist order and reclaims even if
the zone is over the high watermark regardless of the age of pages
in that LRU. Kswapd on the other hand starts reclaim on the highest
unbalanced zone. A difference in distribution of file/anon pages due
to when they were allocated results can result in a difference in
again. While the fair zone allocation policy mitigates some of the
problems here, the page reclaim results on a multi-zone node will
always be different to a single-zone node.
it was scheduled on as a result.
3. kswapd and the page allocator scan zones in the opposite order to
avoid interfering with each other but it's sensitive to timing. This
mitigates the page allocator using pages that were allocated very recently
in the ideal case but it's sensitive to timing. When kswapd is allocating
from lower zones then it's great but during the rebalancing of the highest
zone, the page allocator and kswapd interfere with each other. It's worse
if the highest zone is small and difficult to balance.
4. slab shrinkers are node-based which makes it harder to identify the exact
relationship between slab reclaim and LRU reclaim.
The reason we have zone-based reclaim is that we used to have
large highmem zones in common configurations and it was necessary
to quickly find ZONE_NORMAL pages for reclaim. Today, this is much
less of a concern as machines with lots of memory will (or should) use
64-bit kernels. Combinations of 32-bit hardware and 64-bit hardware are
rare. Machines that do use highmem should have relatively low highmem:lowmem
ratios than we worried about in the past.
Conceptually, moving to node LRUs should be easier to understand. The
page allocator plays fewer tricks to game reclaim and reclaim behaves
similarly on all nodes.
The series has been tested on a 16 core UMA machine and a 2-socket 48
core NUMA machine. The UMA results are presented in most cases as the NUMA
machine behaved similarly.
pagealloc
---------
This is a microbenchmark that shows the benefit of removing the fair zone
allocation policy. It was tested uip to order-4 but only orders 0 and 1 are
shown as the other orders were comparable.
4.7.0-rc4 4.7.0-rc4
mmotm-20160623 nodelru-v9
Min total-odr0-1 490.00 ( 0.00%) 457.00 ( 6.73%)
Min total-odr0-2 347.00 ( 0.00%) 329.00 ( 5.19%)
Min total-odr0-4 288.00 ( 0.00%) 273.00 ( 5.21%)
Min total-odr0-8 251.00 ( 0.00%) 239.00 ( 4.78%)
Min total-odr0-16 234.00 ( 0.00%) 222.00 ( 5.13%)
Min total-odr0-32 223.00 ( 0.00%) 211.00 ( 5.38%)
Min total-odr0-64 217.00 ( 0.00%) 208.00 ( 4.15%)
Min total-odr0-128 214.00 ( 0.00%) 204.00 ( 4.67%)
Min total-odr0-256 250.00 ( 0.00%) 230.00 ( 8.00%)
Min total-odr0-512 271.00 ( 0.00%) 269.00 ( 0.74%)
Min total-odr0-1024 291.00 ( 0.00%) 282.00 ( 3.09%)
Min total-odr0-2048 303.00 ( 0.00%) 296.00 ( 2.31%)
Min total-odr0-4096 311.00 ( 0.00%) 309.00 ( 0.64%)
Min total-odr0-8192 316.00 ( 0.00%) 314.00 ( 0.63%)
Min total-odr0-16384 317.00 ( 0.00%) 315.00 ( 0.63%)
Min total-odr1-1 742.00 ( 0.00%) 712.00 ( 4.04%)
Min total-odr1-2 562.00 ( 0.00%) 530.00 ( 5.69%)
Min total-odr1-4 457.00 ( 0.00%) 433.00 ( 5.25%)
Min total-odr1-8 411.00 ( 0.00%) 381.00 ( 7.30%)
Min total-odr1-16 381.00 ( 0.00%) 356.00 ( 6.56%)
Min total-odr1-32 372.00 ( 0.00%) 346.00 ( 6.99%)
Min total-odr1-64 372.00 ( 0.00%) 343.00 ( 7.80%)
Min total-odr1-128 375.00 ( 0.00%) 351.00 ( 6.40%)
Min total-odr1-256 379.00 ( 0.00%) 351.00 ( 7.39%)
Min total-odr1-512 385.00 ( 0.00%) 355.00 ( 7.79%)
Min total-odr1-1024 386.00 ( 0.00%) 358.00 ( 7.25%)
Min total-odr1-2048 390.00 ( 0.00%) 362.00 ( 7.18%)
Min total-odr1-4096 390.00 ( 0.00%) 362.00 ( 7.18%)
Min total-odr1-8192 388.00 ( 0.00%) 363.00 ( 6.44%)
This shows a steady improvement throughout. The primary benefit is from
reduced system CPU usage which is obvious from the overall times;
4.7.0-rc4 4.7.0-rc4
mmotm-20160623nodelru-v8
User 189.19 191.80
System 2604.45 2533.56
Elapsed 2855.30 2786.39
The vmstats also showed that the fair zone allocation policy was definitely
removed as can be seen here;
4.7.0-rc3 4.7.0-rc3
mmotm-20160623 nodelru-v8
DMA32 allocs 28794729769 0
Normal allocs 48432501431 77227309877
Movable allocs 0 0
tiobench on ext4
----------------
tiobench is a benchmark that artifically benefits if old pages remain resident
while new pages get reclaimed. The fair zone allocation policy mitigates this
problem so pages age fairly. While the benchmark has problems, it is important
that tiobench performance remains constant as it implies that page aging
problems that the fair zone allocation policy fixes are not re-introduced.
4.7.0-rc4 4.7.0-rc4
mmotm-20160623 nodelru-v9
Min PotentialReadSpeed 89.65 ( 0.00%) 90.21 ( 0.62%)
Min SeqRead-MB/sec-1 82.68 ( 0.00%) 82.01 ( -0.81%)
Min SeqRead-MB/sec-2 72.76 ( 0.00%) 72.07 ( -0.95%)
Min SeqRead-MB/sec-4 75.13 ( 0.00%) 74.92 ( -0.28%)
Min SeqRead-MB/sec-8 64.91 ( 0.00%) 65.19 ( 0.43%)
Min SeqRead-MB/sec-16 62.24 ( 0.00%) 62.22 ( -0.03%)
Min RandRead-MB/sec-1 0.88 ( 0.00%) 0.88 ( 0.00%)
Min RandRead-MB/sec-2 0.95 ( 0.00%) 0.92 ( -3.16%)
Min RandRead-MB/sec-4 1.43 ( 0.00%) 1.34 ( -6.29%)
Min RandRead-MB/sec-8 1.61 ( 0.00%) 1.60 ( -0.62%)
Min RandRead-MB/sec-16 1.80 ( 0.00%) 1.90 ( 5.56%)
Min SeqWrite-MB/sec-1 76.41 ( 0.00%) 76.85 ( 0.58%)
Min SeqWrite-MB/sec-2 74.11 ( 0.00%) 73.54 ( -0.77%)
Min SeqWrite-MB/sec-4 80.05 ( 0.00%) 80.13 ( 0.10%)
Min SeqWrite-MB/sec-8 72.88 ( 0.00%) 73.20 ( 0.44%)
Min SeqWrite-MB/sec-16 75.91 ( 0.00%) 76.44 ( 0.70%)
Min RandWrite-MB/sec-1 1.18 ( 0.00%) 1.14 ( -3.39%)
Min RandWrite-MB/sec-2 1.02 ( 0.00%) 1.03 ( 0.98%)
Min RandWrite-MB/sec-4 1.05 ( 0.00%) 0.98 ( -6.67%)
Min RandWrite-MB/sec-8 0.89 ( 0.00%) 0.92 ( 3.37%)
Min RandWrite-MB/sec-16 0.92 ( 0.00%) 0.93 ( 1.09%)
4.7.0-rc4 4.7.0-rc4
mmotm-20160623 approx-v9
User 645.72 525.90
System 403.85 331.75
Elapsed 6795.36 6783.67
This shows that the series has little or not impact on tiobench which is
desirable and a reduction in system CPU usage. It indicates that the fair
zone allocation policy was removed in a manner that didn't reintroduce
one class of page aging bug. There were only minor differences in overall
reclaim activity
4.7.0-rc4 4.7.0-rc4
mmotm-20160623nodelru-v8
Minor Faults 645838 647465
Major Faults 573 640
Swap Ins 0 0
Swap Outs 0 0
DMA allocs 0 0
DMA32 allocs 46041453 44190646
Normal allocs 78053072 79887245
Movable allocs 0 0
Allocation stalls 24 67
Stall zone DMA 0 0
Stall zone DMA32 0 0
Stall zone Normal 0 2
Stall zone HighMem 0 0
Stall zone Movable 0 65
Direct pages scanned 10969 30609
Kswapd pages scanned 93375144 93492094
Kswapd pages reclaimed 93372243 93489370
Direct pages reclaimed 10969 30609
Kswapd efficiency 99% 99%
Kswapd velocity 13741.015 13781.934
Direct efficiency 100% 100%
Direct velocity 1.614 4.512
Percentage direct scans 0% 0%
kswapd activity was roughly comparable. There were differences in direct
reclaim activity but negligible in the context of the overall workload
(velocity of 4 pages per second with the patches applied, 1.6 pages per
second in the baseline kernel).
pgbench read-only large configuration on ext4
---------------------------------------------
pgbench is a database benchmark that can be sensitive to page reclaim
decisions. This also checks if removing the fair zone allocation policy
is safe
pgbench Transactions
4.7.0-rc4 4.7.0-rc4
mmotm-20160623 nodelru-v8
Hmean 1 188.26 ( 0.00%) 189.78 ( 0.81%)
Hmean 5 330.66 ( 0.00%) 328.69 ( -0.59%)
Hmean 12 370.32 ( 0.00%) 380.72 ( 2.81%)
Hmean 21 368.89 ( 0.00%) 369.00 ( 0.03%)
Hmean 30 382.14 ( 0.00%) 360.89 ( -5.56%)
Hmean 32 428.87 ( 0.00%) 432.96 ( 0.95%)
Negligible differences again. As with tiobench, overall reclaim activity
was comparable.
bonnie++ on ext4
----------------
No interesting performance difference, negligible differences on reclaim
stats.
paralleldd on ext4
------------------
This workload uses varying numbers of dd instances to read large amounts of
data from disk.
4.7.0-rc3 4.7.0-rc3
mmotm-20160623 nodelru-v9
Amean Elapsd-1 186.04 ( 0.00%) 189.41 ( -1.82%)
Amean Elapsd-3 192.27 ( 0.00%) 191.38 ( 0.46%)
Amean Elapsd-5 185.21 ( 0.00%) 182.75 ( 1.33%)
Amean Elapsd-7 183.71 ( 0.00%) 182.11 ( 0.87%)
Amean Elapsd-12 180.96 ( 0.00%) 181.58 ( -0.35%)
Amean Elapsd-16 181.36 ( 0.00%) 183.72 ( -1.30%)
4.7.0-rc4 4.7.0-rc4
mmotm-20160623 nodelru-v9
User 1548.01 1552.44
System 8609.71 8515.08
Elapsed 3587.10 3594.54
There is little or no change in performance but some drop in system CPU usage.
4.7.0-rc3 4.7.0-rc3
mmotm-20160623 nodelru-v9
Minor Faults 362662 367360
Major Faults 1204 1143
Swap Ins 22 0
Swap Outs 2855 1029
DMA allocs 0 0
DMA32 allocs 31409797 28837521
Normal allocs 46611853 49231282
Movable allocs 0 0
Direct pages scanned 0 0
Kswapd pages scanned 40845270 40869088
Kswapd pages reclaimed 40830976 40855294
Direct pages reclaimed 0 0
Kswapd efficiency 99% 99%
Kswapd velocity 11386.711 11369.769
Direct efficiency 100% 100%
Direct velocity 0.000 0.000
Percentage direct scans 0% 0%
Page writes by reclaim 2855 1029
Page writes file 0 0
Page writes anon 2855 1029
Page reclaim immediate 771 1628
Sector Reads 293312636 293536360
Sector Writes 18213568 18186480
Page rescued immediate 0 0
Slabs scanned 128257 132747
Direct inode steals 181 56
Kswapd inode steals 59 1131
It basically shows that kswapd was active at roughly the same rate in
both kernels. There was also comparable slab scanning activity and direct
reclaim was avoided in both cases. There appears to be a large difference
in numbers of inodes reclaimed but the workload has few active inodes and
is likely a timing artifact.
stutter
-------
stutter simulates a simple workload. One part uses a lot of anonymous
memory, a second measures mmap latency and a third copies a large file.
The primary metric is checking for mmap latency.
stutter
4.7.0-rc4 4.7.0-rc4
mmotm-20160623 nodelru-v8
Min mmap 16.6283 ( 0.00%) 13.4258 ( 19.26%)
1st-qrtle mmap 54.7570 ( 0.00%) 34.9121 ( 36.24%)
2nd-qrtle mmap 57.3163 ( 0.00%) 46.1147 ( 19.54%)
3rd-qrtle mmap 58.9976 ( 0.00%) 47.1882 ( 20.02%)
Max-90% mmap 59.7433 ( 0.00%) 47.4453 ( 20.58%)
Max-93% mmap 60.1298 ( 0.00%) 47.6037 ( 20.83%)
Max-95% mmap 73.4112 ( 0.00%) 82.8719 (-12.89%)
Max-99% mmap 92.8542 ( 0.00%) 88.8870 ( 4.27%)
Max mmap 1440.6569 ( 0.00%) 121.4201 ( 91.57%)
Mean mmap 59.3493 ( 0.00%) 42.2991 ( 28.73%)
Best99%Mean mmap 57.2121 ( 0.00%) 41.8207 ( 26.90%)
Best95%Mean mmap 55.9113 ( 0.00%) 39.9620 ( 28.53%)
Best90%Mean mmap 55.6199 ( 0.00%) 39.3124 ( 29.32%)
Best50%Mean mmap 53.2183 ( 0.00%) 33.1307 ( 37.75%)
Best10%Mean mmap 45.9842 ( 0.00%) 20.4040 ( 55.63%)
Best5%Mean mmap 43.2256 ( 0.00%) 17.9654 ( 58.44%)
Best1%Mean mmap 32.9388 ( 0.00%) 16.6875 ( 49.34%)
This shows a number of improvements with the worst-case outlier greatly
improved.
Some of the vmstats are interesting
4.7.0-rc4 4.7.0-rc4
mmotm-20160623nodelru-v8
Swap Ins 163 502
Swap Outs 0 0
DMA allocs 0 0
DMA32 allocs 618719206 1381662383
Normal allocs 891235743 564138421
Movable allocs 0 0
Allocation stalls 2603 1
Direct pages scanned 216787 2
Kswapd pages scanned 50719775 41778378
Kswapd pages reclaimed 41541765 41777639
Direct pages reclaimed 209159 0
Kswapd efficiency 81% 99%
Kswapd velocity 16859.554 14329.059
Direct efficiency 96% 0%
Direct velocity 72.061 0.001
Percentage direct scans 0% 0%
Page writes by reclaim 6215049 0
Page writes file 6215049 0
Page writes anon 0 0
Page reclaim immediate 70673 90
Sector Reads 81940800 81680456
Sector Writes 100158984 98816036
Page rescued immediate 0 0
Slabs scanned 1366954 22683
While this is not guaranteed in all cases, this particular test showed
a large reduction in direct reclaim activity. It's also worth noting
that no page writes were issued from reclaim context.
This series is not without its hazards. There are at least three areas
that I'm concerned with even though I could not reproduce any problems in
that area.
1. Reclaim/compaction is going to be affected because the amount of reclaim is
no longer targetted at a specific zone. Compaction works on a per-zone basis
so there is no guarantee that reclaiming a few THP's worth page pages will
have a positive impact on compaction success rates.
2. The Slab/LRU reclaim ratio is affected because the frequency the shrinkers
are called is now different. This may or may not be a problem but if it
is, it'll be because shrinkers are not called enough and some balancing
is required.
3. The anon/file reclaim ratio may be affected. Pages about to be dirtied are
distributed between zones and the fair zone allocation policy used to do
something very similar for anon. The distribution is now different but not
necessarily in any way that matters but it's still worth bearing in mind.
VM statistic counters for reclaim decisions are zone-based. If the kernel
is to reclaim on a per-node basis then we need to track per-node
statistics but there is no infrastructure for that. The most notable
change is that the old node_page_state is renamed to
sum_zone_node_page_state. The new node_page_state takes a pglist_data and
uses per-node stats but none exist yet. There is some renaming such as
vm_stat to vm_zone_stat and the addition of vm_node_stat and the renaming
of mod_state to mod_zone_state. Otherwise, this is mostly a mechanical
patch with no functional change. There is a lot of similarity between the
node and zone helpers which is unfortunate but there was no obvious way of
reusing the code and maintaining type safety.
Link: http://lkml.kernel.org/r/1467970510-21195-2-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
a621184ac6 |
mm, meminit: remove early_page_nid_uninitialised
The helper early_page_nid_uninitialised() has been dead since commit
|
||
zhong jiang
|
400bc7fd4f |
mm: update the comment in __isolate_free_page
We need to assure the comment is consistent with the code. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1466171914-21027-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Kirill A. Shutemov
|
65c453778a |
mm, rmap: account shmem thp pages
Let's add ShmemHugePages and ShmemPmdMapped fields into meminfo and smaps. It indicates how many times we allocate and map shmem THP. NR_ANON_TRANSPARENT_HUGEPAGES is renamed to NR_ANON_THPS. Link: http://lkml.kernel.org/r/1466021202-61880-27-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Kirill A. Shutemov
|
9a73f61bdb |
thp, mlock: do not mlock PTE-mapped file huge pages
As with anon THP, we only mlock file huge pages if we can prove that the page is not mapped with PTE. This way we can avoid mlock leak into non-mlocked vma on split. We rely on PageDoubleMap() under lock_page() to check if the the page may be PTE mapped. PG_double_map is set by page_add_file_rmap() when the page mapped with PTEs. Link: http://lkml.kernel.org/r/1466021202-61880-21-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Vladimir Davydov
|
4949148ad4 |
mm: charge/uncharge kmemcg from generic page allocator paths
Currently, to charge a non-slab allocation to kmemcg one has to use alloc_kmem_pages helper with __GFP_ACCOUNT flag. A page allocated with this helper should finally be freed using free_kmem_pages, otherwise it won't be uncharged. This API suits its current users fine, but it turns out to be impossible to use along with page reference counting, i.e. when an allocation is supposed to be freed with put_page, as it is the case with pipe or unix socket buffers. To overcome this limitation, this patch moves charging/uncharging to generic page allocator paths, i.e. to __alloc_pages_nodemask and free_pages_prepare, and zaps alloc/free_kmem_pages helpers. This way, one can use any of the available page allocation functions to get the allocated page charged to kmemcg - it's enough to pass __GFP_ACCOUNT, just like in case of kmalloc and friends. A charged page will be automatically uncharged on free. To make it possible, we need to mark pages charged to kmemcg somehow. To avoid introducing a new page flag, we make use of page->_mapcount for marking such pages. Since pages charged to kmemcg are not supposed to be mapped to userspace, it should work just fine. There are other (ab)users of page->_mapcount - buddy and balloon pages - but we don't conflict with them. In case kmemcg is compiled out or not used at runtime, this patch introduces no overhead to generic page allocator paths. If kmemcg is used, it will be plus one gfp flags check on alloc and plus one page->_mapcount check on free, which shouldn't hurt performance, because the data accessed are hot. Link: http://lkml.kernel.org/r/a9736d856f895bcb465d9f257b54efe32eda6f99.1464079538.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Vladimir Davydov
|
452647784b |
mm: memcontrol: cleanup kmem charge functions
- Handle memcg_kmem_enabled check out to the caller. This reduces the number of function definitions making the code easier to follow. At the same time it doesn't result in code bloat, because all of these functions are used only in one or two places. - Move __GFP_ACCOUNT check to the caller as well so that one wouldn't have to dive deep into memcg implementation to see which allocations are charged and which are not. - Refresh comments. Link: http://lkml.kernel.org/r/52882a28b542c1979fd9a033b4dc8637fc347399.1464079537.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Joonsoo Kim
|
46f24fd857 |
mm/page_alloc: introduce post allocation processing on page allocator
This patch is motivated from Hugh and Vlastimil's concern [1]. There are two ways to get freepage from the allocator. One is using normal memory allocation API and the other is __isolate_free_page() which is internally used for compaction and pageblock isolation. Later usage is rather tricky since it doesn't do whole post allocation processing done by normal API. One problematic thing I already know is that poisoned page would not be checked if it is allocated by __isolate_free_page(). Perhaps, there would be more. We could add more debug logic for allocated page in the future and this separation would cause more problem. I'd like to fix this situation at this time. Solution is simple. This patch commonize some logic for newly allocated page and uses it on all sites. This will solve the problem. [1] http://marc.info/?i=alpine.LSU.2.11.1604270029350.7066%40eggly.anvils%3E [iamjoonsoo.kim@lge.com: mm-page_alloc-introduce-post-allocation-processing-on-page-allocator-v3] Link: http://lkml.kernel.org/r/1464230275-25791-7-git-send-email-iamjoonsoo.kim@lge.com Link: http://lkml.kernel.org/r/1466150259-27727-9-git-send-email-iamjoonsoo.kim@lge.com Link: http://lkml.kernel.org/r/1464230275-25791-7-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
a9627bc5e3 |
mm/page_owner: introduce split_page_owner and replace manual handling
split_page() calls set_page_owner() to set up page_owner to each pages. But, it has a drawback that head page and the others have different stacktrace because callsite of set_page_owner() is slightly differnt. To avoid this problem, this patch copies head page's page_owner to the others. It needs to introduce new function, split_page_owner() but it also remove the other function, get_page_owner_gfp() so looks good to do. Link: http://lkml.kernel.org/r/1464230275-25791-4-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
83358ece26 |
mm/page_owner: initialize page owner without holding the zone lock
It's not necessary to initialized page_owner with holding the zone lock. It would cause more contention on the zone lock although it's not a big problem since it is just debug feature. But, it is better than before so do it. This is also preparation step to use stackdepot in page owner feature. Stackdepot allocates new pages when there is no reserved space and holding the zone lock in this case will cause deadlock. Link: http://lkml.kernel.org/r/1464230275-25791-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
66c64223ad |
mm/compaction: split freepages without holding the zone lock
We don't need to split freepages with holding the zone lock. It will cause more contention on zone lock so not desirable. [rientjes@google.com: if __isolate_free_page() fails, avoid adding to freelist so we don't call map_pages() with it] Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1606211447001.43430@chino.kir.corp.google.com Link: http://lkml.kernel.org/r/1464230275-25791-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Minchan Kim
|
bda807d444 |
mm: migrate: support non-lru movable page migration
We have allowed migration for only LRU pages until now and it was enough to make high-order pages. But recently, embedded system(e.g., webOS, android) uses lots of non-movable pages(e.g., zram, GPU memory) so we have seen several reports about troubles of small high-order allocation. For fixing the problem, there were several efforts (e,g,. enhance compaction algorithm, SLUB fallback to 0-order page, reserved memory, vmalloc and so on) but if there are lots of non-movable pages in system, their solutions are void in the long run. So, this patch is to support facility to change non-movable pages with movable. For the feature, this patch introduces functions related to migration to address_space_operations as well as some page flags. If a driver want to make own pages movable, it should define three functions which are function pointers of struct address_space_operations. 1. bool (*isolate_page) (struct page *page, isolate_mode_t mode); What VM expects on isolate_page function of driver is to return *true* if driver isolates page successfully. On returing true, VM marks the page as PG_isolated so concurrent isolation in several CPUs skip the page for isolation. If a driver cannot isolate the page, it should return *false*. Once page is successfully isolated, VM uses page.lru fields so driver shouldn't expect to preserve values in that fields. 2. int (*migratepage) (struct address_space *mapping, struct page *newpage, struct page *oldpage, enum migrate_mode); After isolation, VM calls migratepage of driver with isolated page. The function of migratepage is to move content of the old page to new page and set up fields of struct page newpage. Keep in mind that you should indicate to the VM the oldpage is no longer movable via __ClearPageMovable() under page_lock if you migrated the oldpage successfully and returns 0. If driver cannot migrate the page at the moment, driver can return -EAGAIN. On -EAGAIN, VM will retry page migration in a short time because VM interprets -EAGAIN as "temporal migration failure". On returning any error except -EAGAIN, VM will give up the page migration without retrying in this time. Driver shouldn't touch page.lru field VM using in the functions. 3. void (*putback_page)(struct page *); If migration fails on isolated page, VM should return the isolated page to the driver so VM calls driver's putback_page with migration failed page. In this function, driver should put the isolated page back to the own data structure. 4. non-lru movable page flags There are two page flags for supporting non-lru movable page. * PG_movable Driver should use the below function to make page movable under page_lock. void __SetPageMovable(struct page *page, struct address_space *mapping) It needs argument of address_space for registering migration family functions which will be called by VM. Exactly speaking, PG_movable is not a real flag of struct page. Rather than, VM reuses page->mapping's lower bits to represent it. #define PAGE_MAPPING_MOVABLE 0x2 page->mapping = page->mapping | PAGE_MAPPING_MOVABLE; so driver shouldn't access page->mapping directly. Instead, driver should use page_mapping which mask off the low two bits of page->mapping so it can get right struct address_space. For testing of non-lru movable page, VM supports __PageMovable function. However, it doesn't guarantee to identify non-lru movable page because page->mapping field is unified with other variables in struct page. As well, if driver releases the page after isolation by VM, page->mapping doesn't have stable value although it has PAGE_MAPPING_MOVABLE (Look at __ClearPageMovable). But __PageMovable is cheap to catch whether page is LRU or non-lru movable once the page has been isolated. Because LRU pages never can have PAGE_MAPPING_MOVABLE in page->mapping. It is also good for just peeking to test non-lru movable pages before more expensive checking with lock_page in pfn scanning to select victim. For guaranteeing non-lru movable page, VM provides PageMovable function. Unlike __PageMovable, PageMovable functions validates page->mapping and mapping->a_ops->isolate_page under lock_page. The lock_page prevents sudden destroying of page->mapping. Driver using __SetPageMovable should clear the flag via __ClearMovablePage under page_lock before the releasing the page. * PG_isolated To prevent concurrent isolation among several CPUs, VM marks isolated page as PG_isolated under lock_page. So if a CPU encounters PG_isolated non-lru movable page, it can skip it. Driver doesn't need to manipulate the flag because VM will set/clear it automatically. Keep in mind that if driver sees PG_isolated page, it means the page have been isolated by VM so it shouldn't touch page.lru field. PG_isolated is alias with PG_reclaim flag so driver shouldn't use the flag for own purpose. [opensource.ganesh@gmail.com: mm/compaction: remove local variable is_lru] Link: http://lkml.kernel.org/r/20160618014841.GA7422@leo-test Link: http://lkml.kernel.org/r/1464736881-24886-3-git-send-email-minchan@kernel.org Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: John Einar Reitan <john.reitan@foss.arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Vladimir Davydov
|
2a966b77ae |
mm: oom: add memcg to oom_control
It's a part of oom context just like allocation order and nodemask, so let's move it to oom_control instead of passing it in the argument list. Link: http://lkml.kernel.org/r/40e03fd7aaf1f55c75d787128d6d17c5a71226c2.1464358556.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Oliver O'Halloran
|
90cae1fe1c |
mm/init: fix zone boundary creation
As a part of memory initialisation the architecture passes an array to
free_area_init_nodes() which specifies the max PFN of each memory zone.
This array is not necessarily monotonic (due to unused zones) so this
array is parsed to build monotonic lists of the min and max PFN for each
zone. ZONE_MOVABLE is special cased here as its limits are managed by
the mm subsystem rather than the architecture. Unfortunately, this
special casing is broken when ZONE_MOVABLE is the not the last zone in
the zone list. The core of the issue is:
if (i == ZONE_MOVABLE)
continue;
arch_zone_lowest_possible_pfn[i] =
arch_zone_highest_possible_pfn[i-1];
As ZONE_MOVABLE is skipped the lowest_possible_pfn of the next zone will
be set to zero. This patch fixes this bug by adding explicitly tracking
where the next zone should start rather than relying on the contents
arch_zone_highest_possible_pfn[].
Thie is low priority. To get bitten by this you need to enable a zone
that appears after ZONE_MOVABLE in the zone_type enum. As far as I can
tell this means running a kernel with ZONE_DEVICE or ZONE_CMA enabled,
so I can't see this affecting too many people.
I only noticed this because I've been fiddling with ZONE_DEVICE on
powerpc and 4.6 broke my test kernel. This bug, in conjunction with the
changes in Taku Izumi's kernelcore=mirror patch (
|
||
|
Mel Gorman
|
ef70b6f41c |
mm, meminit: ensure node is online before checking whether pages are uninitialised
early_page_uninitialised looks up an arbitrary PFN. While a machine without node 0 will boot with "mm, page_alloc: Always return a valid node from early_pfn_to_nid", it works because it assumes that nodes are always in PFN order. This is not guaranteed so this patch adds robustness by always checking if the node being checked is online. Link: http://lkml.kernel.org/r/1468008031-3848-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
e4568d3803 |
mm, meminit: always return a valid node from early_pfn_to_nid
early_pfn_to_nid can return node 0 if a PFN is invalid on machines that
has no node 0. A machine with only node 1 was observed to crash with
the following message:
BUG: unable to handle kernel paging request at 000000000002a3c8
PGD 0
Modules linked in:
Hardware name: Supermicro H8DSP-8/H8DSP-8, BIOS 080011 06/30/2006
task: ffffffff81c0d500 ti: ffffffff81c00000 task.ti: ffffffff81c00000
RIP: reserve_bootmem_region+0x6a/0xef
CR2: 000000000002a3c8 CR3: 0000000001c06000 CR4: 00000000000006b0
Call Trace:
free_all_bootmem+0x4b/0x12a
mem_init+0x70/0xa3
start_kernel+0x25b/0x49b
The problem is that early_page_uninitialised uses the early_pfn_to_nid
helper which returns node 0 for invalid PFNs. No caller of
early_pfn_to_nid cares except early_page_uninitialised. This patch has
early_pfn_to_nid always return a valid node.
Link: http://lkml.kernel.org/r/1468008031-3848-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
e46e7b77c9 |
mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies
The optimistic fast path may use cpuset_current_mems_allowed instead of
of a NULL nodemask supplied by the caller for cpuset allocations. The
preferred zone is calculated on this basis for statistic purposes and as
a starting point in the zonelist iterator.
However, if the context can ignore memory policies due to being atomic
or being able to ignore watermarks then the starting point in the
zonelist iterator is no longer correct. This patch resets the zonelist
iterator in the allocator slowpath if the context can ignore memory
policies. This will alter the zone used for statistics but only after
it is known that it makes sense for that context. Resetting it before
entering the slowpath would potentially allow an ALLOC_CPUSET allocation
to be accounted for against the wrong zone. Note that while nodemask is
not explicitly set to the original nodemask, it would only have been
overwritten if cpuset_enabled() and it was reset before the slowpath was
entered.
Link: http://lkml.kernel.org/r/20160602103936.GU2527@techsingularity.net
Fixes:
|
||
|
Mel Gorman
|
0d0bd89435 |
mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy
Geert Uytterhoeven reported the following problem that bisected to commit |
||
|
Vlastimil Babka
|
83b9355bf6 |
mm, page_alloc: prevent infinite loop in buffered_rmqueue()
In DEBUG_VM kernel, we can hit infinite loop for order == 0 in
buffered_rmqueue() when check_new_pcp() returns 1, because the bad page
is never removed from the pcp list. Fix this by removing the page
before retrying. Also we don't need to check if page is non-NULL,
because we simply grab it from the list which was just tested for being
non-empty.
Fixes:
|
||
Yang Shi
|
f86e427197 |
mm: check the return value of lookup_page_ext for all call sites
Per the discussion with Joonsoo Kim [1], we need check the return value of lookup_page_ext() for all call sites since it might return NULL in some cases, although it is unlikely, i.e. memory hotplug. Tested with ltp with "page_owner=0". [1] http://lkml.kernel.org/r/20160519002809.GA10245@js1304-P5Q-DELUXE [akpm@linux-foundation.org: fix build-breaking typos] [arnd@arndb.de: fix build problems from lookup_page_ext] Link: http://lkml.kernel.org/r/6285269.2CksypHdYp@wuerfel [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1464023768-31025-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Naoya Horiguchi
|
e570f56ccc |
mm: check_new_page_bad() directly returns in __PG_HWPOISON case
Currently we check page->flags twice for "HWPoisoned" case of check_new_page_bad(), which can cause a race with unpoisoning. This race unnecessarily taints kernel with "BUG: Bad page state". check_new_page_bad() is the only caller of bad_page() which is interested in __PG_HWPOISON, so let's move the hwpoison related code in bad_page() to it. Link: http://lkml.kernel.org/r/20160518100949.GA17299@hori1.linux.bs1.fc.nec.co.jp Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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seokhoon.yoon
|
29b52de182 |
mm, kasan: fix to call kasan_free_pages() after poisoning page
When CONFIG_PAGE_POISONING and CONFIG_KASAN is enabled,
free_pages_prepare()'s codeflow is below.
1)kmemcheck_free_shadow()
2)kasan_free_pages()
- set shadow byte of page is freed
3)kernel_poison_pages()
3.1) check access to page is valid or not using kasan
---> error occur, kasan think it is invalid access
3.2) poison page
4)kernel_map_pages()
So kasan_free_pages() should be called after poisoning the page.
Link: http://lkml.kernel.org/r/1463220405-7455-1-git-send-email-iamyooon@gmail.com
Signed-off-by: seokhoon.yoon <iamyooon@gmail.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
Stefan Bader
|
4b50bcc7ed |
mm: use phys_addr_t for reserve_bootmem_region() arguments
Since commit |
||
Minfei Huang
|
2a138dc7e5 |
mm: use existing helper to convert "on"/"off" to boolean
It's more convenient to use existing function helper to convert string "on/off" to boolean. Link: http://lkml.kernel.org/r/1461908824-16129-1-git-send-email-mnghuan@gmail.com Signed-off-by: Minfei Huang <mnghuan@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Michal Hocko
|
31e49bfda1 |
mm, oom: protect !costly allocations some more for !CONFIG_COMPACTION
Joonsoo has reported that he is able to trigger OOM for !costly high order requests (heavy fork() workload close the OOM) with the new oom detection rework. This is because we rely only on should_reclaim_retry when the compaction is disabled and it only checks watermarks for the requested order and so we might trigger OOM when there is a lot of free memory. It is not very clear what are the usual workloads when the compaction is disabled. Relying on high order allocations heavily without any mechanism to create those orders except for unbound amount of reclaim is certainly not a good idea. To prevent from potential regressions let's help this configuration some. We have to sacrifice the determinsm though because there simply is none here possible. should_compact_retry implementation for !CONFIG_COMPACTION, which was empty so far, will do watermark check for order-0 on all eligible zones. This will cause retrying until either the reclaim cannot make any further progress or all the zones are depleted even for order-0 pages. This means that the number of retries is basically unbounded for !costly orders but that was the case before the rework as well so this shouldn't regress. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1463051677-29418-3-git-send-email-mhocko@kernel.org Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
|
86a294a81f |
mm, oom, compaction: prevent from should_compact_retry looping for ever for costly orders
"mm: consider compaction feedback also for costly allocation" has
removed the upper bound for the reclaim/compaction retries based on the
number of reclaimed pages for costly orders. While this is desirable
the patch did miss a mis interaction between reclaim, compaction and the
retry logic. The direct reclaim tries to get zones over min watermark
while compaction backs off and returns COMPACT_SKIPPED when all zones
are below low watermark + 1<<order gap. If we are getting really close
to OOM then __compaction_suitable can keep returning COMPACT_SKIPPED a
high order request (e.g. hugetlb order-9) while the reclaim is not able
to release enough pages to get us over low watermark. The reclaim is
still able to make some progress (usually trashing over few remaining
pages) so we are not able to break out from the loop.
I have seen this happening with the same test described in "mm: consider
compaction feedback also for costly allocation" on a swapless system.
The original problem got resolved by "vmscan: consider classzone_idx in
compaction_ready" but it shows how things might go wrong when we
approach the oom event horizont.
The reason why compaction requires being over low rather than min
watermark is not clear to me. This check was there essentially since
|
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Michal Hocko
|
7854ea6c28 |
mm: consider compaction feedback also for costly allocation
PAGE_ALLOC_COSTLY_ORDER retry logic is mostly handled inside
should_reclaim_retry currently where we decide to not retry after at
least order worth of pages were reclaimed or the watermark check for at
least one zone would succeed after reclaiming all pages if the reclaim
hasn't made any progress. Compaction feedback is mostly ignored and we
just try to make sure that the compaction did at least something before
giving up.
The first condition was added by
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Michal Hocko
|
33c2d21438 |
mm, oom: protect !costly allocations some more
should_reclaim_retry will give up retries for higher order allocations if none of the eligible zones has any requested or higher order pages available even if we pass the watermak check for order-0. This is done because there is no guarantee that the reclaimable and currently free pages will form the required order. This can, however, lead to situations where the high-order request (e.g. order-2 required for the stack allocation during fork) will trigger OOM too early - e.g. after the first reclaim/compaction round. Such a system would have to be highly fragmented and there is no guarantee further reclaim/compaction attempts would help but at least make sure that the compaction was active before we go OOM and keep retrying even if should_reclaim_retry tells us to oom if - the last compaction round backed off or - we haven't completed at least MAX_COMPACT_RETRIES active compaction rounds. The first rule ensures that the very last attempt for compaction was not ignored while the second guarantees that the compaction has done some work. Multiple retries might be needed to prevent occasional pigggy backing of other contexts to steal the compacted pages before the current context manages to retry to allocate them. compaction_failed() is taken as a final word from the compaction that the retry doesn't make much sense. We have to be careful though because the first compaction round is MIGRATE_ASYNC which is rather weak as it ignores pages under writeback and gives up too easily in other situations. We therefore have to make sure that MIGRATE_SYNC_LIGHT mode has been used before we give up. With this logic in place we do not have to increase the migration mode unconditionally and rather do it only if the compaction failed for the weaker mode. A nice side effect is that the stronger migration mode is used only when really needed so this has a potential of smaller latencies in some cases. Please note that the compaction doesn't tell us much about how successful it was when returning compaction_made_progress so we just have to blindly trust that another retry is worthwhile and cap the number to something reasonable to guarantee a convergence. If the given number of successful retries is not sufficient for a reasonable workloads we should focus on the collected compaction tracepoints data and try to address the issue in the compaction code. If this is not feasible we can increase the retries limit. [mhocko@suse.com: fix warning] Link: http://lkml.kernel.org/r/20160512061636.GA4200@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michal Hocko
|
ede3771373 |
mm: throttle on IO only when there are too many dirty and writeback pages
wait_iff_congested has been used to throttle allocator before it retried another round of direct reclaim to allow the writeback to make some progress and prevent reclaim from looping over dirty/writeback pages without making any progress. We used to do congestion_wait before commit |
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|
Michal Hocko
|
0a0337e0d1 |
mm, oom: rework oom detection
__alloc_pages_slowpath has traditionally relied on the direct reclaim and did_some_progress as an indicator that it makes sense to retry allocation rather than declaring OOM. shrink_zones had to rely on zone_reclaimable if shrink_zone didn't make any progress to prevent from a premature OOM killer invocation - the LRU might be full of dirty or writeback pages and direct reclaim cannot clean those up. zone_reclaimable allows to rescan the reclaimable lists several times and restart if a page is freed. This is really subtle behavior and it might lead to a livelock when a single freed page keeps allocator looping but the current task will not be able to allocate that single page. OOM killer would be more appropriate than looping without any progress for unbounded amount of time. This patch changes OOM detection logic and pulls it out from shrink_zone which is too low to be appropriate for any high level decisions such as OOM which is per zonelist property. It is __alloc_pages_slowpath which knows how many attempts have been done and what was the progress so far therefore it is more appropriate to implement this logic. The new heuristic is implemented in should_reclaim_retry helper called from __alloc_pages_slowpath. It tries to be more deterministic and easier to follow. It builds on an assumption that retrying makes sense only if the currently reclaimable memory + free pages would allow the current allocation request to succeed (as per __zone_watermark_ok) at least for one zone in the usable zonelist. This alone wouldn't be sufficient, though, because the writeback might get stuck and reclaimable pages might be pinned for a really long time or even depend on the current allocation context. Therefore there is a backoff mechanism implemented which reduces the reclaim target after each reclaim round without any progress. This means that we should eventually converge to only NR_FREE_PAGES as the target and fail on the wmark check and proceed to OOM. The backoff is simple and linear with 1/16 of the reclaimable pages for each round without any progress. We are optimistic and reset counter for successful reclaim rounds. Costly high order pages mostly preserve their semantic and those without __GFP_REPEAT fail right away while those which have the flag set will back off after the amount of reclaimable pages reaches equivalent of the requested order. The only difference is that if there was no progress during the reclaim we rely on zone watermark check. This is more logical thing to do than previous 1<<order attempts which were a result of zone_reclaimable faking the progress. [vdavydov@virtuozzo.com: check classzone_idx for shrink_zone] [hannes@cmpxchg.org: separate the heuristic into should_reclaim_retry] [rientjes@google.com: use zone_page_state_snapshot for NR_FREE_PAGES] [rientjes@google.com: shrink_zones doesn't need to return anything] Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michal Hocko
|
c5d01d0d18 |
mm, compaction: simplify __alloc_pages_direct_compact feedback interface
__alloc_pages_direct_compact communicates potential back off by two variables: - deferred_compaction tells that the compaction returned COMPACT_DEFERRED - contended_compaction is set when there is a contention on zone->lock resp. zone->lru_lock locks __alloc_pages_slowpath then backs of for THP allocation requests to prevent from long stalls. This is rather messy and it would be much cleaner to return a single compact result value and hide all the nasty details into __alloc_pages_direct_compact. This patch shouldn't introduce any functional changes. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michal Hocko
|
ea7ab982b6 |
mm, compaction: change COMPACT_ constants into enum
Compaction code is doing weird dances between COMPACT_FOO -> int -> unsigned long But there doesn't seem to be any reason for that. All functions which return/use one of those constants are not expecting any other value so it really makes sense to define an enum for them and make it clear that no other values are expected. This is a pure cleanup and shouldn't introduce any functional changes. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Rik van Riel
|
59dc76b0d4 |
mm: vmscan: reduce size of inactive file list
The inactive file list should still be large enough to contain readahead windows and freshly written file data, but it no longer is the only source for detecting multiple accesses to file pages. The workingset refault measurement code causes recently evicted file pages that get accessed again after a shorter interval to be promoted directly to the active list. With that mechanism in place, we can afford to (on a larger system) dedicate more memory to the active file list, so we can actually cache more of the frequently used file pages in memory, and not have them pushed out by streaming writes, once-used streaming file reads, etc. This can help things like database workloads, where only half the page cache can currently be used to cache the database working set. This patch automatically increases that fraction on larger systems, using the same ratio that has already been used for anonymous memory. [hannes@cmpxchg.org: cgroup-awareness] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Andres Freund <andres@anarazel.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Mel Gorman
|
4741526b83 |
mm, page_alloc: restore the original nodemask if the fast path allocation failed
The page allocator fast path uses either the requested nodemask or cpuset_current_mems_allowed if cpusets are enabled. If the allocation context allows watermarks to be ignored then it can also ignore memory policies. However, on entering the allocator slowpath the nodemask may still be cpuset_current_mems_allowed and the policies are enforced. This patch resets the nodemask appropriately before entering the slowpath. Link: http://lkml.kernel.org/r/20160504143628.GU2858@techsingularity.net Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Vlastimil Babka
|
4e6118016e |
mm, page_alloc: uninline the bad page part of check_new_page()
Bad pages should be rare so the code handling them doesn't need to be inline for performance reasons. Put it to separate function which returns void. This also assumes that the initial page_expected_state() result will match the result of the thorough check, i.e. the page doesn't become "good" in the meanwhile. This matches the same expectations already in place in free_pages_check(). !DEBUG_VM bloat-o-meter: add/remove: 1/0 grow/shrink: 0/1 up/down: 134/-274 (-140) function old new delta check_new_page_bad - 134 +134 get_page_from_freelist 3468 3194 -274 Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
e2769dbdc5 |
mm, page_alloc: don't duplicate code in free_pcp_prepare
The new free_pcp_prepare() function shares a lot of code with free_pages_prepare(), which makes this a maintenance risk when some future patch modifies only one of them. We should be able to achieve the same effect (skipping free_pages_check() from !DEBUG_VM configs) by adding a parameter to free_pages_prepare() and making it inline, so the checks (and the order != 0 parts) are eliminated from the call from free_pcp_prepare(). !DEBUG_VM: bloat-o-meter reports no difference, as my gcc was already inlining free_pages_prepare() and the elimination seems to work as expected DEBUG_VM bloat-o-meter: add/remove: 0/1 grow/shrink: 2/0 up/down: 1035/-778 (257) function old new delta __free_pages_ok 297 1060 +763 free_hot_cold_page 480 752 +272 free_pages_prepare 778 - -778 Here inlining didn't occur before, and added some code, but it's ok for a debug option. [akpm@linux-foundation.org: fix build] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
479f854a20 |
mm, page_alloc: defer debugging checks of pages allocated from the PCP
Every page allocated checks a number of page fields for validity. This
catches corruption bugs of pages that are already freed but it is
expensive. This patch weakens the debugging check by checking PCP pages
only when the PCP lists are being refilled. All compound pages are
checked. This potentially avoids debugging checks entirely if the PCP
lists are never emptied and refilled so some corruption issues may be
missed. Full checking requires DEBUG_VM.
With the two deferred debugging patches applied, the impact to a page
allocator microbenchmark is
4.6.0-rc3 4.6.0-rc3
inline-v3r6 deferalloc-v3r7
Min alloc-odr0-1 344.00 ( 0.00%) 317.00 ( 7.85%)
Min alloc-odr0-2 248.00 ( 0.00%) 231.00 ( 6.85%)
Min alloc-odr0-4 209.00 ( 0.00%) 192.00 ( 8.13%)
Min alloc-odr0-8 181.00 ( 0.00%) 166.00 ( 8.29%)
Min alloc-odr0-16 168.00 ( 0.00%) 154.00 ( 8.33%)
Min alloc-odr0-32 161.00 ( 0.00%) 148.00 ( 8.07%)
Min alloc-odr0-64 158.00 ( 0.00%) 145.00 ( 8.23%)
Min alloc-odr0-128 156.00 ( 0.00%) 143.00 ( 8.33%)
Min alloc-odr0-256 168.00 ( 0.00%) 154.00 ( 8.33%)
Min alloc-odr0-512 178.00 ( 0.00%) 167.00 ( 6.18%)
Min alloc-odr0-1024 186.00 ( 0.00%) 174.00 ( 6.45%)
Min alloc-odr0-2048 192.00 ( 0.00%) 180.00 ( 6.25%)
Min alloc-odr0-4096 198.00 ( 0.00%) 184.00 ( 7.07%)
Min alloc-odr0-8192 200.00 ( 0.00%) 188.00 ( 6.00%)
Min alloc-odr0-16384 201.00 ( 0.00%) 188.00 ( 6.47%)
Min free-odr0-1 189.00 ( 0.00%) 180.00 ( 4.76%)
Min free-odr0-2 132.00 ( 0.00%) 126.00 ( 4.55%)
Min free-odr0-4 104.00 ( 0.00%) 99.00 ( 4.81%)
Min free-odr0-8 90.00 ( 0.00%) 85.00 ( 5.56%)
Min free-odr0-16 84.00 ( 0.00%) 80.00 ( 4.76%)
Min free-odr0-32 80.00 ( 0.00%) 76.00 ( 5.00%)
Min free-odr0-64 78.00 ( 0.00%) 74.00 ( 5.13%)
Min free-odr0-128 77.00 ( 0.00%) 73.00 ( 5.19%)
Min free-odr0-256 94.00 ( 0.00%) 91.00 ( 3.19%)
Min free-odr0-512 108.00 ( 0.00%) 112.00 ( -3.70%)
Min free-odr0-1024 115.00 ( 0.00%) 118.00 ( -2.61%)
Min free-odr0-2048 120.00 ( 0.00%) 125.00 ( -4.17%)
Min free-odr0-4096 123.00 ( 0.00%) 129.00 ( -4.88%)
Min free-odr0-8192 126.00 ( 0.00%) 130.00 ( -3.17%)
Min free-odr0-16384 126.00 ( 0.00%) 131.00 ( -3.97%)
Note that the free paths for large numbers of pages is impacted as the
debugging cost gets shifted into that path when the page data is no
longer necessarily cache-hot.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
4db7548ccb |
mm, page_alloc: defer debugging checks of freed pages until a PCP drain
Every page free checks a number of page fields for validity. This catches premature frees and corruptions but it is also expensive. This patch weakens the debugging check by checking PCP pages at the time they are drained from the PCP list. This will trigger the bug but the site that freed the corrupt page will be lost. To get the full context, a kernel rebuild with DEBUG_VM is necessary. [akpm@linux-foundation.org: fix build] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Vlastimil Babka
|
002f290627 |
cpuset: use static key better and convert to new API
An important function for cpusets is cpuset_node_allowed(), which
optimizes on the fact if there's a single root CPU set, it must be
trivially allowed. But the check "nr_cpusets() <= 1" doesn't use the
cpusets_enabled_key static key the right way where static keys eliminate
branching overhead with jump labels.
This patch converts it so that static key is used properly. It's also
switched to the new static key API and the checking functions are
converted to return bool instead of int. We also provide a new variant
__cpuset_zone_allowed() which expects that the static key check was
already done and they key was enabled. This is needed for
get_page_from_freelist() where we want to also avoid the relatively
slower check when ALLOC_CPUSET is not set in alloc_flags.
The impact on the page allocator microbenchmark is less than expected
but the cleanup in itself is worthwhile.
4.6.0-rc2 4.6.0-rc2
multcheck-v1r20 cpuset-v1r20
Min alloc-odr0-1 348.00 ( 0.00%) 348.00 ( 0.00%)
Min alloc-odr0-2 254.00 ( 0.00%) 254.00 ( 0.00%)
Min alloc-odr0-4 213.00 ( 0.00%) 213.00 ( 0.00%)
Min alloc-odr0-8 186.00 ( 0.00%) 183.00 ( 1.61%)
Min alloc-odr0-16 173.00 ( 0.00%) 171.00 ( 1.16%)
Min alloc-odr0-32 166.00 ( 0.00%) 163.00 ( 1.81%)
Min alloc-odr0-64 162.00 ( 0.00%) 159.00 ( 1.85%)
Min alloc-odr0-128 160.00 ( 0.00%) 157.00 ( 1.88%)
Min alloc-odr0-256 169.00 ( 0.00%) 166.00 ( 1.78%)
Min alloc-odr0-512 180.00 ( 0.00%) 180.00 ( 0.00%)
Min alloc-odr0-1024 188.00 ( 0.00%) 187.00 ( 0.53%)
Min alloc-odr0-2048 194.00 ( 0.00%) 193.00 ( 0.52%)
Min alloc-odr0-4096 199.00 ( 0.00%) 198.00 ( 0.50%)
Min alloc-odr0-8192 202.00 ( 0.00%) 201.00 ( 0.50%)
Min alloc-odr0-16384 203.00 ( 0.00%) 202.00 ( 0.49%)
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Zefan Li <lizefan@huawei.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
0b423ca22f |
mm, page_alloc: inline pageblock lookup in page free fast paths
The function call overhead of get_pfnblock_flags_mask() is measurable in the page free paths. This patch uses an inlined version that is faster. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
e5b31ac2ca |
mm, page_alloc: remove unnecessary variable from free_pcppages_bulk
The original count is never reused so it can be removed. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
da838d4fcb |
mm, page_alloc: pull out side effects from free_pages_check
Check without side-effects should be easier to maintain. It also removes the duplicated cpupid and flags reset done in !DEBUG_VM variant of both free_pcp_prepare() and then bulkfree_pcp_prepare(). Finally, it enables the next patch. It shouldn't result in new branches, thanks to inlining of the check. !DEBUG_VM bloat-o-meter: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-27 (-27) function old new delta __free_pages_ok 748 739 -9 free_pcppages_bulk 1403 1385 -18 DEBUG_VM: add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-28 (-28) function old new delta free_pages_prepare 806 778 -28 This is also slightly faster because cpupid information is not set on tail pages so we can avoid resets there. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
bb552ac6c6 |
mm, page_alloc: un-inline the bad part of free_pages_check
From: Vlastimil Babka <vbabka@suse.cz> !DEBUG_VM size and bloat-o-meter: add/remove: 1/0 grow/shrink: 0/2 up/down: 124/-370 (-246) function old new delta free_pages_check_bad - 124 +124 free_pcppages_bulk 1288 1171 -117 __free_pages_ok 948 695 -253 DEBUG_VM: add/remove: 1/0 grow/shrink: 0/1 up/down: 124/-214 (-90) function old new delta free_pages_check_bad - 124 +124 free_pages_prepare 1112 898 -214 [akpm@linux-foundation.org: fix whitespace] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
7bfec6f47b |
mm, page_alloc: check multiple page fields with a single branch
Every page allocated or freed is checked for sanity to avoid corruptions
that are difficult to detect later. A bad page could be due to a number
of fields. Instead of using multiple branches, this patch combines
multiple fields into a single branch. A detailed check is only
necessary if that check fails.
4.6.0-rc2 4.6.0-rc2
initonce-v1r20 multcheck-v1r20
Min alloc-odr0-1 359.00 ( 0.00%) 348.00 ( 3.06%)
Min alloc-odr0-2 260.00 ( 0.00%) 254.00 ( 2.31%)
Min alloc-odr0-4 214.00 ( 0.00%) 213.00 ( 0.47%)
Min alloc-odr0-8 186.00 ( 0.00%) 186.00 ( 0.00%)
Min alloc-odr0-16 173.00 ( 0.00%) 173.00 ( 0.00%)
Min alloc-odr0-32 165.00 ( 0.00%) 166.00 ( -0.61%)
Min alloc-odr0-64 162.00 ( 0.00%) 162.00 ( 0.00%)
Min alloc-odr0-128 161.00 ( 0.00%) 160.00 ( 0.62%)
Min alloc-odr0-256 170.00 ( 0.00%) 169.00 ( 0.59%)
Min alloc-odr0-512 181.00 ( 0.00%) 180.00 ( 0.55%)
Min alloc-odr0-1024 190.00 ( 0.00%) 188.00 ( 1.05%)
Min alloc-odr0-2048 196.00 ( 0.00%) 194.00 ( 1.02%)
Min alloc-odr0-4096 202.00 ( 0.00%) 199.00 ( 1.49%)
Min alloc-odr0-8192 205.00 ( 0.00%) 202.00 ( 1.46%)
Min alloc-odr0-16384 205.00 ( 0.00%) 203.00 ( 0.98%)
Again, the benefit is marginal but avoiding excessive branches is
important. Ideally the paths would not have to check these conditions
at all but regrettably abandoning the tests would make use-after-free
bugs much harder to detect.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
93ea9964d1 |
mm, page_alloc: remove field from alloc_context
The classzone_idx can be inferred from preferred_zoneref so remove the unnecessary field and save stack space. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
c33d6c06f6 |
mm, page_alloc: avoid looking up the first zone in a zonelist twice
The allocator fast path looks up the first usable zone in a zonelist and
then get_page_from_freelist does the same job in the zonelist iterator.
This patch preserves the necessary information.
4.6.0-rc2 4.6.0-rc2
fastmark-v1r20 initonce-v1r20
Min alloc-odr0-1 364.00 ( 0.00%) 359.00 ( 1.37%)
Min alloc-odr0-2 262.00 ( 0.00%) 260.00 ( 0.76%)
Min alloc-odr0-4 214.00 ( 0.00%) 214.00 ( 0.00%)
Min alloc-odr0-8 186.00 ( 0.00%) 186.00 ( 0.00%)
Min alloc-odr0-16 173.00 ( 0.00%) 173.00 ( 0.00%)
Min alloc-odr0-32 165.00 ( 0.00%) 165.00 ( 0.00%)
Min alloc-odr0-64 161.00 ( 0.00%) 162.00 ( -0.62%)
Min alloc-odr0-128 159.00 ( 0.00%) 161.00 ( -1.26%)
Min alloc-odr0-256 168.00 ( 0.00%) 170.00 ( -1.19%)
Min alloc-odr0-512 180.00 ( 0.00%) 181.00 ( -0.56%)
Min alloc-odr0-1024 190.00 ( 0.00%) 190.00 ( 0.00%)
Min alloc-odr0-2048 196.00 ( 0.00%) 196.00 ( 0.00%)
Min alloc-odr0-4096 202.00 ( 0.00%) 202.00 ( 0.00%)
Min alloc-odr0-8192 206.00 ( 0.00%) 205.00 ( 0.49%)
Min alloc-odr0-16384 206.00 ( 0.00%) 205.00 ( 0.49%)
The benefit is negligible and the results are within the noise but each
cycle counts.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
48ee5f3696 |
mm, page_alloc: shortcut watermark checks for order-0 pages
Watermarks have to be checked on every allocation including the number
of pages being allocated and whether reserves can be accessed. The
reserves only matter if memory is limited and the free_pages adjustment
only applies to high-order pages. This patch adds a shortcut for
order-0 pages that avoids numerous calculations if there is plenty of
free memory yielding the following performance difference in a page
allocator microbenchmark;
4.6.0-rc2 4.6.0-rc2
optfair-v1r20 fastmark-v1r20
Min alloc-odr0-1 380.00 ( 0.00%) 364.00 ( 4.21%)
Min alloc-odr0-2 273.00 ( 0.00%) 262.00 ( 4.03%)
Min alloc-odr0-4 227.00 ( 0.00%) 214.00 ( 5.73%)
Min alloc-odr0-8 196.00 ( 0.00%) 186.00 ( 5.10%)
Min alloc-odr0-16 183.00 ( 0.00%) 173.00 ( 5.46%)
Min alloc-odr0-32 173.00 ( 0.00%) 165.00 ( 4.62%)
Min alloc-odr0-64 169.00 ( 0.00%) 161.00 ( 4.73%)
Min alloc-odr0-128 169.00 ( 0.00%) 159.00 ( 5.92%)
Min alloc-odr0-256 180.00 ( 0.00%) 168.00 ( 6.67%)
Min alloc-odr0-512 190.00 ( 0.00%) 180.00 ( 5.26%)
Min alloc-odr0-1024 198.00 ( 0.00%) 190.00 ( 4.04%)
Min alloc-odr0-2048 204.00 ( 0.00%) 196.00 ( 3.92%)
Min alloc-odr0-4096 209.00 ( 0.00%) 202.00 ( 3.35%)
Min alloc-odr0-8192 213.00 ( 0.00%) 206.00 ( 3.29%)
Min alloc-odr0-16384 214.00 ( 0.00%) 206.00 ( 3.74%)
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
305347550b |
mm, page_alloc: reduce cost of fair zone allocation policy retry
The fair zone allocation policy is not without cost but it can be
reduced slightly. This patch removes an unnecessary local variable,
checks the likely conditions of the fair zone policy first, uses a bool
instead of a flags check and falls through when a remote node is
encountered instead of doing a full restart. The benefit is marginal
but it's there
4.6.0-rc2 4.6.0-rc2
decstat-v1r20 optfair-v1r20
Min alloc-odr0-1 377.00 ( 0.00%) 380.00 ( -0.80%)
Min alloc-odr0-2 273.00 ( 0.00%) 273.00 ( 0.00%)
Min alloc-odr0-4 226.00 ( 0.00%) 227.00 ( -0.44%)
Min alloc-odr0-8 196.00 ( 0.00%) 196.00 ( 0.00%)
Min alloc-odr0-16 183.00 ( 0.00%) 183.00 ( 0.00%)
Min alloc-odr0-32 175.00 ( 0.00%) 173.00 ( 1.14%)
Min alloc-odr0-64 172.00 ( 0.00%) 169.00 ( 1.74%)
Min alloc-odr0-128 170.00 ( 0.00%) 169.00 ( 0.59%)
Min alloc-odr0-256 183.00 ( 0.00%) 180.00 ( 1.64%)
Min alloc-odr0-512 191.00 ( 0.00%) 190.00 ( 0.52%)
Min alloc-odr0-1024 199.00 ( 0.00%) 198.00 ( 0.50%)
Min alloc-odr0-2048 204.00 ( 0.00%) 204.00 ( 0.00%)
Min alloc-odr0-4096 210.00 ( 0.00%) 209.00 ( 0.48%)
Min alloc-odr0-8192 213.00 ( 0.00%) 213.00 ( 0.00%)
Min alloc-odr0-16384 214.00 ( 0.00%) 214.00 ( 0.00%)
The benefit is marginal at best but one of the most important benefits,
avoiding a second search when falling back to another node is not
triggered by this particular test so the benefit for some corner cases
is understated.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
4fcb097117 |
mm, page_alloc: shorten the page allocator fast path
The page allocator fast path checks page multiple times unnecessarily. This patch avoids all the slowpath checks if the first allocation attempt succeeds. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
3777999dd4 |
mm, page_alloc: check once if a zone has isolated pageblocks
When bulk freeing pages from the per-cpu lists the zone is checked for isolated pageblocks on every release. This patch checks it once per drain. [mgorman@techsingularity.net: fix locking radce, per Vlastimil] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
83d4ca8148 |
mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath
__GFP_HARDWALL only has meaning in the context of cpusets but the fast
path always applies the flag on the first attempt. Move the
manipulations into the cpuset paths where they will be masked by a
static branch in the common case.
With the other micro-optimisations in this series combined, the impact
on a page allocator microbenchmark is
4.6.0-rc2 4.6.0-rc2
decstat-v1r20 micro-v1r20
Min alloc-odr0-1 381.00 ( 0.00%) 377.00 ( 1.05%)
Min alloc-odr0-2 275.00 ( 0.00%) 273.00 ( 0.73%)
Min alloc-odr0-4 229.00 ( 0.00%) 226.00 ( 1.31%)
Min alloc-odr0-8 199.00 ( 0.00%) 196.00 ( 1.51%)
Min alloc-odr0-16 186.00 ( 0.00%) 183.00 ( 1.61%)
Min alloc-odr0-32 179.00 ( 0.00%) 175.00 ( 2.23%)
Min alloc-odr0-64 174.00 ( 0.00%) 172.00 ( 1.15%)
Min alloc-odr0-128 172.00 ( 0.00%) 170.00 ( 1.16%)
Min alloc-odr0-256 181.00 ( 0.00%) 183.00 ( -1.10%)
Min alloc-odr0-512 193.00 ( 0.00%) 191.00 ( 1.04%)
Min alloc-odr0-1024 201.00 ( 0.00%) 199.00 ( 1.00%)
Min alloc-odr0-2048 206.00 ( 0.00%) 204.00 ( 0.97%)
Min alloc-odr0-4096 212.00 ( 0.00%) 210.00 ( 0.94%)
Min alloc-odr0-8192 215.00 ( 0.00%) 213.00 ( 0.93%)
Min alloc-odr0-16384 216.00 ( 0.00%) 214.00 ( 0.93%)
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
5bb1b16975 |
mm, page_alloc: remove unnecessary initialisation from __alloc_pages_nodemask()
page is guaranteed to be set before it is read with or without the initialisation. [akpm@linux-foundation.org: fix warning] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
be06af002f |
mm, page_alloc: remove unnecessary initialisation in get_page_from_freelist
Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
4dfa6cd8fd |
mm, page_alloc: remove unnecessary local variable in get_page_from_freelist
zonelist here is a copy of a struct field that is used once. Ditch it. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
fa379b9586 |
mm, page_alloc: convert nr_fair_skipped to bool
The number of zones skipped to a zone expiring its fair zone allocation quota is irrelevant. Convert to bool. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
c603844bdc |
mm, page_alloc: convert alloc_flags to unsigned
alloc_flags is a bitmask of flags but it is signed which does not necessarily generate the best code depending on the compiler. Even without an impact, it makes more sense that this be unsigned. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
f75fb889d1 |
mm, page_alloc: avoid unnecessary zone lookups during pageblock operations
Pageblocks have an associated bitmap to store migrate types and whether the pageblock should be skipped during compaction. The bitmap may be associated with a memory section or a zone but the zone is looked up unconditionally. The compiler should optimise this away automatically so this is a cosmetic patch only in many cases. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
754078eb45 |
mm, page_alloc: use __dec_zone_state for order-0 page allocation
__dec_zone_state is cheaper to use for removing an order-0 page as it
has fewer conditions to check.
The performance difference on a page allocator microbenchmark is;
4.6.0-rc2 4.6.0-rc2
optiter-v1r20 decstat-v1r20
Min alloc-odr0-1 382.00 ( 0.00%) 381.00 ( 0.26%)
Min alloc-odr0-2 282.00 ( 0.00%) 275.00 ( 2.48%)
Min alloc-odr0-4 233.00 ( 0.00%) 229.00 ( 1.72%)
Min alloc-odr0-8 203.00 ( 0.00%) 199.00 ( 1.97%)
Min alloc-odr0-16 188.00 ( 0.00%) 186.00 ( 1.06%)
Min alloc-odr0-32 182.00 ( 0.00%) 179.00 ( 1.65%)
Min alloc-odr0-64 177.00 ( 0.00%) 174.00 ( 1.69%)
Min alloc-odr0-128 175.00 ( 0.00%) 172.00 ( 1.71%)
Min alloc-odr0-256 184.00 ( 0.00%) 181.00 ( 1.63%)
Min alloc-odr0-512 197.00 ( 0.00%) 193.00 ( 2.03%)
Min alloc-odr0-1024 203.00 ( 0.00%) 201.00 ( 0.99%)
Min alloc-odr0-2048 209.00 ( 0.00%) 206.00 ( 1.44%)
Min alloc-odr0-4096 214.00 ( 0.00%) 212.00 ( 0.93%)
Min alloc-odr0-8192 218.00 ( 0.00%) 215.00 ( 1.38%)
Min alloc-odr0-16384 219.00 ( 0.00%) 216.00 ( 1.37%)
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
682a3385e7 |
mm, page_alloc: inline the fast path of the zonelist iterator
The page allocator iterates through a zonelist for zones that match the
addressing limitations and nodemask of the caller but many allocations
will not be restricted. Despite this, there is always functional call
overhead which builds up.
This patch inlines the optimistic basic case and only calls the iterator
function for the complex case. A hindrance was the fact that
cpuset_current_mems_allowed is used in the fastpath as the allowed
nodemask even though all nodes are allowed on most systems. The patch
handles this by only considering cpuset_current_mems_allowed if a cpuset
exists. As well as being faster in the fast-path, this removes some
junk in the slowpath.
The performance difference on a page allocator microbenchmark is;
4.6.0-rc2 4.6.0-rc2
statinline-v1r20 optiter-v1r20
Min alloc-odr0-1 412.00 ( 0.00%) 382.00 ( 7.28%)
Min alloc-odr0-2 301.00 ( 0.00%) 282.00 ( 6.31%)
Min alloc-odr0-4 247.00 ( 0.00%) 233.00 ( 5.67%)
Min alloc-odr0-8 215.00 ( 0.00%) 203.00 ( 5.58%)
Min alloc-odr0-16 199.00 ( 0.00%) 188.00 ( 5.53%)
Min alloc-odr0-32 191.00 ( 0.00%) 182.00 ( 4.71%)
Min alloc-odr0-64 187.00 ( 0.00%) 177.00 ( 5.35%)
Min alloc-odr0-128 185.00 ( 0.00%) 175.00 ( 5.41%)
Min alloc-odr0-256 193.00 ( 0.00%) 184.00 ( 4.66%)
Min alloc-odr0-512 207.00 ( 0.00%) 197.00 ( 4.83%)
Min alloc-odr0-1024 213.00 ( 0.00%) 203.00 ( 4.69%)
Min alloc-odr0-2048 220.00 ( 0.00%) 209.00 ( 5.00%)
Min alloc-odr0-4096 226.00 ( 0.00%) 214.00 ( 5.31%)
Min alloc-odr0-8192 229.00 ( 0.00%) 218.00 ( 4.80%)
Min alloc-odr0-16384 229.00 ( 0.00%) 219.00 ( 4.37%)
perf indicated that next_zones_zonelist disappeared in the profile and
__next_zones_zonelist did not appear. This is expected as the
micro-benchmark would hit the inlined fast-path every time.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
060e74173f |
mm, page_alloc: inline zone_statistics
zone_statistics has one call-site but it's a public function. Make it
static and inline.
The performance difference on a page allocator microbenchmark is;
4.6.0-rc2 4.6.0-rc2
statbranch-v1r20 statinline-v1r20
Min alloc-odr0-1 419.00 ( 0.00%) 412.00 ( 1.67%)
Min alloc-odr0-2 305.00 ( 0.00%) 301.00 ( 1.31%)
Min alloc-odr0-4 250.00 ( 0.00%) 247.00 ( 1.20%)
Min alloc-odr0-8 219.00 ( 0.00%) 215.00 ( 1.83%)
Min alloc-odr0-16 203.00 ( 0.00%) 199.00 ( 1.97%)
Min alloc-odr0-32 195.00 ( 0.00%) 191.00 ( 2.05%)
Min alloc-odr0-64 191.00 ( 0.00%) 187.00 ( 2.09%)
Min alloc-odr0-128 189.00 ( 0.00%) 185.00 ( 2.12%)
Min alloc-odr0-256 198.00 ( 0.00%) 193.00 ( 2.53%)
Min alloc-odr0-512 210.00 ( 0.00%) 207.00 ( 1.43%)
Min alloc-odr0-1024 216.00 ( 0.00%) 213.00 ( 1.39%)
Min alloc-odr0-2048 221.00 ( 0.00%) 220.00 ( 0.45%)
Min alloc-odr0-4096 227.00 ( 0.00%) 226.00 ( 0.44%)
Min alloc-odr0-8192 232.00 ( 0.00%) 229.00 ( 1.29%)
Min alloc-odr0-16384 232.00 ( 0.00%) 229.00 ( 1.29%)
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
175145748d |
mm, page_alloc: use new PageAnonHead helper in the free page fast path
The PageAnon check always checks for compound_head but this is a
relatively expensive check if the caller already knows the page is a
head page. This patch creates a helper and uses it in the page free
path which only operates on head pages.
With this patch and "Only check PageCompound for high-order pages", the
performance difference on a page allocator microbenchmark is;
4.6.0-rc2 4.6.0-rc2
vanilla nocompound-v1r20
Min alloc-odr0-1 425.00 ( 0.00%) 417.00 ( 1.88%)
Min alloc-odr0-2 313.00 ( 0.00%) 308.00 ( 1.60%)
Min alloc-odr0-4 257.00 ( 0.00%) 253.00 ( 1.56%)
Min alloc-odr0-8 224.00 ( 0.00%) 221.00 ( 1.34%)
Min alloc-odr0-16 208.00 ( 0.00%) 205.00 ( 1.44%)
Min alloc-odr0-32 199.00 ( 0.00%) 199.00 ( 0.00%)
Min alloc-odr0-64 195.00 ( 0.00%) 193.00 ( 1.03%)
Min alloc-odr0-128 192.00 ( 0.00%) 191.00 ( 0.52%)
Min alloc-odr0-256 204.00 ( 0.00%) 200.00 ( 1.96%)
Min alloc-odr0-512 213.00 ( 0.00%) 212.00 ( 0.47%)
Min alloc-odr0-1024 219.00 ( 0.00%) 219.00 ( 0.00%)
Min alloc-odr0-2048 225.00 ( 0.00%) 225.00 ( 0.00%)
Min alloc-odr0-4096 230.00 ( 0.00%) 231.00 ( -0.43%)
Min alloc-odr0-8192 235.00 ( 0.00%) 234.00 ( 0.43%)
Min alloc-odr0-16384 235.00 ( 0.00%) 234.00 ( 0.43%)
Min free-odr0-1 215.00 ( 0.00%) 191.00 ( 11.16%)
Min free-odr0-2 152.00 ( 0.00%) 136.00 ( 10.53%)
Min free-odr0-4 119.00 ( 0.00%) 107.00 ( 10.08%)
Min free-odr0-8 106.00 ( 0.00%) 96.00 ( 9.43%)
Min free-odr0-16 97.00 ( 0.00%) 87.00 ( 10.31%)
Min free-odr0-32 91.00 ( 0.00%) 83.00 ( 8.79%)
Min free-odr0-64 89.00 ( 0.00%) 81.00 ( 8.99%)
Min free-odr0-128 88.00 ( 0.00%) 80.00 ( 9.09%)
Min free-odr0-256 106.00 ( 0.00%) 95.00 ( 10.38%)
Min free-odr0-512 116.00 ( 0.00%) 111.00 ( 4.31%)
Min free-odr0-1024 125.00 ( 0.00%) 118.00 ( 5.60%)
Min free-odr0-2048 133.00 ( 0.00%) 126.00 ( 5.26%)
Min free-odr0-4096 136.00 ( 0.00%) 130.00 ( 4.41%)
Min free-odr0-8192 138.00 ( 0.00%) 130.00 ( 5.80%)
Min free-odr0-16384 137.00 ( 0.00%) 130.00 ( 5.11%)
There is a sizable boost to the free allocator performance. While there
is an apparent boost on the allocation side, it's likely a co-incidence
or due to the patches slightly reducing cache footprint.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
d61f859039 |
mm, page_alloc: only check PageCompound for high-order pages
Another year, another round of page allocator optimisations focusing
this time on the alloc and free fast paths. This should be of help to
workloads that are allocator-intensive from kernel space where the cost
of zeroing is not nceessraily incurred.
The series is motivated by the observation that page alloc
microbenchmarks on multiple machines regressed between 3.12.44 and 4.4.
Second, there is discussions before LSF/MM considering the possibility
of adding another page allocator which is potentially hazardous but a
patch series improving performance is better than whining.
After the series is applied, there are still hazards. In the free
paths, the debugging checking and page zone/pageblock lookups dominate
but there was not an obvious solution to that. In the alloc path, the
major contributers are dealing with zonelists, new page preperation, the
fair zone allocation and numerous statistic updates. The fair zone
allocator is removed by the per-node LRU series if that gets merged so
it's nor a major concern at the moment.
On normal userspace benchmarks, there is little impact as the zeroing
cost is significant but it's visible
aim9
4.6.0-rc3 4.6.0-rc3
vanilla deferalloc-v3
Min page_test 828693.33 ( 0.00%) 887060.00 ( 7.04%)
Min brk_test 4847266.67 ( 0.00%) 4966266.67 ( 2.45%)
Min exec_test 1271.00 ( 0.00%) 1275.67 ( 0.37%)
Min fork_test 12371.75 ( 0.00%) 12380.00 ( 0.07%)
The overall impact on a page allocator microbenchmark for a range of orders
and number of pages allocated in a batch is
4.6.0-rc3 4.6.0-rc3
vanilla deferalloc-v3r7
Min alloc-odr0-1 428.00 ( 0.00%) 316.00 ( 26.17%)
Min alloc-odr0-2 314.00 ( 0.00%) 231.00 ( 26.43%)
Min alloc-odr0-4 256.00 ( 0.00%) 192.00 ( 25.00%)
Min alloc-odr0-8 222.00 ( 0.00%) 166.00 ( 25.23%)
Min alloc-odr0-16 207.00 ( 0.00%) 154.00 ( 25.60%)
Min alloc-odr0-32 197.00 ( 0.00%) 148.00 ( 24.87%)
Min alloc-odr0-64 193.00 ( 0.00%) 144.00 ( 25.39%)
Min alloc-odr0-128 191.00 ( 0.00%) 143.00 ( 25.13%)
Min alloc-odr0-256 203.00 ( 0.00%) 153.00 ( 24.63%)
Min alloc-odr0-512 212.00 ( 0.00%) 165.00 ( 22.17%)
Min alloc-odr0-1024 221.00 ( 0.00%) 172.00 ( 22.17%)
Min alloc-odr0-2048 225.00 ( 0.00%) 179.00 ( 20.44%)
Min alloc-odr0-4096 232.00 ( 0.00%) 185.00 ( 20.26%)
Min alloc-odr0-8192 235.00 ( 0.00%) 187.00 ( 20.43%)
Min alloc-odr0-16384 236.00 ( 0.00%) 188.00 ( 20.34%)
Min alloc-odr1-1 519.00 ( 0.00%) 450.00 ( 13.29%)
Min alloc-odr1-2 391.00 ( 0.00%) 336.00 ( 14.07%)
Min alloc-odr1-4 313.00 ( 0.00%) 268.00 ( 14.38%)
Min alloc-odr1-8 277.00 ( 0.00%) 235.00 ( 15.16%)
Min alloc-odr1-16 256.00 ( 0.00%) 218.00 ( 14.84%)
Min alloc-odr1-32 252.00 ( 0.00%) 212.00 ( 15.87%)
Min alloc-odr1-64 244.00 ( 0.00%) 206.00 ( 15.57%)
Min alloc-odr1-128 244.00 ( 0.00%) 207.00 ( 15.16%)
Min alloc-odr1-256 243.00 ( 0.00%) 207.00 ( 14.81%)
Min alloc-odr1-512 245.00 ( 0.00%) 209.00 ( 14.69%)
Min alloc-odr1-1024 248.00 ( 0.00%) 214.00 ( 13.71%)
Min alloc-odr1-2048 253.00 ( 0.00%) 220.00 ( 13.04%)
Min alloc-odr1-4096 258.00 ( 0.00%) 224.00 ( 13.18%)
Min alloc-odr1-8192 261.00 ( 0.00%) 229.00 ( 12.26%)
Min alloc-odr2-1 560.00 ( 0.00%) 753.00 (-34.46%)
Min alloc-odr2-2 424.00 ( 0.00%) 351.00 ( 17.22%)
Min alloc-odr2-4 339.00 ( 0.00%) 393.00 (-15.93%)
Min alloc-odr2-8 298.00 ( 0.00%) 246.00 ( 17.45%)
Min alloc-odr2-16 276.00 ( 0.00%) 227.00 ( 17.75%)
Min alloc-odr2-32 271.00 ( 0.00%) 221.00 ( 18.45%)
Min alloc-odr2-64 264.00 ( 0.00%) 217.00 ( 17.80%)
Min alloc-odr2-128 264.00 ( 0.00%) 217.00 ( 17.80%)
Min alloc-odr2-256 264.00 ( 0.00%) 218.00 ( 17.42%)
Min alloc-odr2-512 269.00 ( 0.00%) 223.00 ( 17.10%)
Min alloc-odr2-1024 279.00 ( 0.00%) 230.00 ( 17.56%)
Min alloc-odr2-2048 283.00 ( 0.00%) 235.00 ( 16.96%)
Min alloc-odr2-4096 285.00 ( 0.00%) 239.00 ( 16.14%)
Min alloc-odr3-1 629.00 ( 0.00%) 505.00 ( 19.71%)
Min alloc-odr3-2 472.00 ( 0.00%) 374.00 ( 20.76%)
Min alloc-odr3-4 383.00 ( 0.00%) 301.00 ( 21.41%)
Min alloc-odr3-8 341.00 ( 0.00%) 266.00 ( 21.99%)
Min alloc-odr3-16 316.00 ( 0.00%) 248.00 ( 21.52%)
Min alloc-odr3-32 308.00 ( 0.00%) 241.00 ( 21.75%)
Min alloc-odr3-64 305.00 ( 0.00%) 241.00 ( 20.98%)
Min alloc-odr3-128 308.00 ( 0.00%) 244.00 ( 20.78%)
Min alloc-odr3-256 317.00 ( 0.00%) 249.00 ( 21.45%)
Min alloc-odr3-512 327.00 ( 0.00%) 256.00 ( 21.71%)
Min alloc-odr3-1024 331.00 ( 0.00%) 261.00 ( 21.15%)
Min alloc-odr3-2048 333.00 ( 0.00%) 266.00 ( 20.12%)
Min alloc-odr4-1 767.00 ( 0.00%) 572.00 ( 25.42%)
Min alloc-odr4-2 578.00 ( 0.00%) 429.00 ( 25.78%)
Min alloc-odr4-4 474.00 ( 0.00%) 346.00 ( 27.00%)
Min alloc-odr4-8 422.00 ( 0.00%) 310.00 ( 26.54%)
Min alloc-odr4-16 399.00 ( 0.00%) 295.00 ( 26.07%)
Min alloc-odr4-32 392.00 ( 0.00%) 293.00 ( 25.26%)
Min alloc-odr4-64 394.00 ( 0.00%) 293.00 ( 25.63%)
Min alloc-odr4-128 405.00 ( 0.00%) 305.00 ( 24.69%)
Min alloc-odr4-256 417.00 ( 0.00%) 319.00 ( 23.50%)
Min alloc-odr4-512 425.00 ( 0.00%) 326.00 ( 23.29%)
Min alloc-odr4-1024 426.00 ( 0.00%) 329.00 ( 22.77%)
Min free-odr0-1 216.00 ( 0.00%) 178.00 ( 17.59%)
Min free-odr0-2 152.00 ( 0.00%) 125.00 ( 17.76%)
Min free-odr0-4 120.00 ( 0.00%) 99.00 ( 17.50%)
Min free-odr0-8 106.00 ( 0.00%) 85.00 ( 19.81%)
Min free-odr0-16 97.00 ( 0.00%) 80.00 ( 17.53%)
Min free-odr0-32 92.00 ( 0.00%) 76.00 ( 17.39%)
Min free-odr0-64 89.00 ( 0.00%) 74.00 ( 16.85%)
Min free-odr0-128 89.00 ( 0.00%) 73.00 ( 17.98%)
Min free-odr0-256 107.00 ( 0.00%) 90.00 ( 15.89%)
Min free-odr0-512 117.00 ( 0.00%) 108.00 ( 7.69%)
Min free-odr0-1024 125.00 ( 0.00%) 118.00 ( 5.60%)
Min free-odr0-2048 132.00 ( 0.00%) 125.00 ( 5.30%)
Min free-odr0-4096 135.00 ( 0.00%) 130.00 ( 3.70%)
Min free-odr0-8192 137.00 ( 0.00%) 130.00 ( 5.11%)
Min free-odr0-16384 137.00 ( 0.00%) 131.00 ( 4.38%)
Min free-odr1-1 318.00 ( 0.00%) 289.00 ( 9.12%)
Min free-odr1-2 228.00 ( 0.00%) 207.00 ( 9.21%)
Min free-odr1-4 182.00 ( 0.00%) 165.00 ( 9.34%)
Min free-odr1-8 163.00 ( 0.00%) 146.00 ( 10.43%)
Min free-odr1-16 151.00 ( 0.00%) 135.00 ( 10.60%)
Min free-odr1-32 146.00 ( 0.00%) 129.00 ( 11.64%)
Min free-odr1-64 145.00 ( 0.00%) 130.00 ( 10.34%)
Min free-odr1-128 148.00 ( 0.00%) 134.00 ( 9.46%)
Min free-odr1-256 148.00 ( 0.00%) 137.00 ( 7.43%)
Min free-odr1-512 151.00 ( 0.00%) 140.00 ( 7.28%)
Min free-odr1-1024 154.00 ( 0.00%) 143.00 ( 7.14%)
Min free-odr1-2048 156.00 ( 0.00%) 144.00 ( 7.69%)
Min free-odr1-4096 156.00 ( 0.00%) 142.00 ( 8.97%)
Min free-odr1-8192 156.00 ( 0.00%) 140.00 ( 10.26%)
Min free-odr2-1 361.00 ( 0.00%) 457.00 (-26.59%)
Min free-odr2-2 258.00 ( 0.00%) 224.00 ( 13.18%)
Min free-odr2-4 208.00 ( 0.00%) 223.00 ( -7.21%)
Min free-odr2-8 185.00 ( 0.00%) 160.00 ( 13.51%)
Min free-odr2-16 173.00 ( 0.00%) 149.00 ( 13.87%)
Min free-odr2-32 166.00 ( 0.00%) 145.00 ( 12.65%)
Min free-odr2-64 166.00 ( 0.00%) 146.00 ( 12.05%)
Min free-odr2-128 169.00 ( 0.00%) 148.00 ( 12.43%)
Min free-odr2-256 170.00 ( 0.00%) 152.00 ( 10.59%)
Min free-odr2-512 177.00 ( 0.00%) 156.00 ( 11.86%)
Min free-odr2-1024 182.00 ( 0.00%) 162.00 ( 10.99%)
Min free-odr2-2048 181.00 ( 0.00%) 160.00 ( 11.60%)
Min free-odr2-4096 180.00 ( 0.00%) 159.00 ( 11.67%)
Min free-odr3-1 431.00 ( 0.00%) 367.00 ( 14.85%)
Min free-odr3-2 306.00 ( 0.00%) 259.00 ( 15.36%)
Min free-odr3-4 249.00 ( 0.00%) 208.00 ( 16.47%)
Min free-odr3-8 224.00 ( 0.00%) 186.00 ( 16.96%)
Min free-odr3-16 208.00 ( 0.00%) 176.00 ( 15.38%)
Min free-odr3-32 206.00 ( 0.00%) 174.00 ( 15.53%)
Min free-odr3-64 210.00 ( 0.00%) 178.00 ( 15.24%)
Min free-odr3-128 215.00 ( 0.00%) 182.00 ( 15.35%)
Min free-odr3-256 224.00 ( 0.00%) 189.00 ( 15.62%)
Min free-odr3-512 232.00 ( 0.00%) 195.00 ( 15.95%)
Min free-odr3-1024 230.00 ( 0.00%) 195.00 ( 15.22%)
Min free-odr3-2048 229.00 ( 0.00%) 193.00 ( 15.72%)
Min free-odr4-1 561.00 ( 0.00%) 439.00 ( 21.75%)
Min free-odr4-2 418.00 ( 0.00%) 318.00 ( 23.92%)
Min free-odr4-4 339.00 ( 0.00%) 269.00 ( 20.65%)
Min free-odr4-8 299.00 ( 0.00%) 239.00 ( 20.07%)
Min free-odr4-16 289.00 ( 0.00%) 234.00 ( 19.03%)
Min free-odr4-32 291.00 ( 0.00%) 235.00 ( 19.24%)
Min free-odr4-64 298.00 ( 0.00%) 238.00 ( 20.13%)
Min free-odr4-128 308.00 ( 0.00%) 251.00 ( 18.51%)
Min free-odr4-256 321.00 ( 0.00%) 267.00 ( 16.82%)
Min free-odr4-512 327.00 ( 0.00%) 269.00 ( 17.74%)
Min free-odr4-1024 326.00 ( 0.00%) 271.00 ( 16.87%)
Min total-odr0-1 644.00 ( 0.00%) 494.00 ( 23.29%)
Min total-odr0-2 466.00 ( 0.00%) 356.00 ( 23.61%)
Min total-odr0-4 376.00 ( 0.00%) 291.00 ( 22.61%)
Min total-odr0-8 328.00 ( 0.00%) 251.00 ( 23.48%)
Min total-odr0-16 304.00 ( 0.00%) 234.00 ( 23.03%)
Min total-odr0-32 289.00 ( 0.00%) 224.00 ( 22.49%)
Min total-odr0-64 282.00 ( 0.00%) 218.00 ( 22.70%)
Min total-odr0-128 280.00 ( 0.00%) 216.00 ( 22.86%)
Min total-odr0-256 310.00 ( 0.00%) 243.00 ( 21.61%)
Min total-odr0-512 329.00 ( 0.00%) 273.00 ( 17.02%)
Min total-odr0-1024 346.00 ( 0.00%) 290.00 ( 16.18%)
Min total-odr0-2048 357.00 ( 0.00%) 304.00 ( 14.85%)
Min total-odr0-4096 367.00 ( 0.00%) 315.00 ( 14.17%)
Min total-odr0-8192 372.00 ( 0.00%) 317.00 ( 14.78%)
Min total-odr0-16384 373.00 ( 0.00%) 319.00 ( 14.48%)
Min total-odr1-1 838.00 ( 0.00%) 739.00 ( 11.81%)
Min total-odr1-2 619.00 ( 0.00%) 543.00 ( 12.28%)
Min total-odr1-4 495.00 ( 0.00%) 433.00 ( 12.53%)
Min total-odr1-8 440.00 ( 0.00%) 382.00 ( 13.18%)
Min total-odr1-16 407.00 ( 0.00%) 353.00 ( 13.27%)
Min total-odr1-32 398.00 ( 0.00%) 341.00 ( 14.32%)
Min total-odr1-64 389.00 ( 0.00%) 336.00 ( 13.62%)
Min total-odr1-128 392.00 ( 0.00%) 341.00 ( 13.01%)
Min total-odr1-256 391.00 ( 0.00%) 344.00 ( 12.02%)
Min total-odr1-512 396.00 ( 0.00%) 349.00 ( 11.87%)
Min total-odr1-1024 402.00 ( 0.00%) 357.00 ( 11.19%)
Min total-odr1-2048 409.00 ( 0.00%) 364.00 ( 11.00%)
Min total-odr1-4096 414.00 ( 0.00%) 366.00 ( 11.59%)
Min total-odr1-8192 417.00 ( 0.00%) 369.00 ( 11.51%)
Min total-odr2-1 921.00 ( 0.00%) 1210.00 (-31.38%)
Min total-odr2-2 682.00 ( 0.00%) 576.00 ( 15.54%)
Min total-odr2-4 547.00 ( 0.00%) 616.00 (-12.61%)
Min total-odr2-8 483.00 ( 0.00%) 406.00 ( 15.94%)
Min total-odr2-16 449.00 ( 0.00%) 376.00 ( 16.26%)
Min total-odr2-32 437.00 ( 0.00%) 366.00 ( 16.25%)
Min total-odr2-64 431.00 ( 0.00%) 363.00 ( 15.78%)
Min total-odr2-128 433.00 ( 0.00%) 365.00 ( 15.70%)
Min total-odr2-256 434.00 ( 0.00%) 371.00 ( 14.52%)
Min total-odr2-512 446.00 ( 0.00%) 379.00 ( 15.02%)
Min total-odr2-1024 461.00 ( 0.00%) 392.00 ( 14.97%)
Min total-odr2-2048 464.00 ( 0.00%) 395.00 ( 14.87%)
Min total-odr2-4096 465.00 ( 0.00%) 398.00 ( 14.41%)
Min total-odr3-1 1060.00 ( 0.00%) 872.00 ( 17.74%)
Min total-odr3-2 778.00 ( 0.00%) 633.00 ( 18.64%)
Min total-odr3-4 632.00 ( 0.00%) 510.00 ( 19.30%)
Min total-odr3-8 565.00 ( 0.00%) 452.00 ( 20.00%)
Min total-odr3-16 524.00 ( 0.00%) 424.00 ( 19.08%)
Min total-odr3-32 514.00 ( 0.00%) 415.00 ( 19.26%)
Min total-odr3-64 515.00 ( 0.00%) 419.00 ( 18.64%)
Min total-odr3-128 523.00 ( 0.00%) 426.00 ( 18.55%)
Min total-odr3-256 541.00 ( 0.00%) 438.00 ( 19.04%)
Min total-odr3-512 559.00 ( 0.00%) 451.00 ( 19.32%)
Min total-odr3-1024 561.00 ( 0.00%) 456.00 ( 18.72%)
Min total-odr3-2048 562.00 ( 0.00%) 459.00 ( 18.33%)
Min total-odr4-1 1328.00 ( 0.00%) 1011.00 ( 23.87%)
Min total-odr4-2 997.00 ( 0.00%) 747.00 ( 25.08%)
Min total-odr4-4 813.00 ( 0.00%) 615.00 ( 24.35%)
Min total-odr4-8 721.00 ( 0.00%) 550.00 ( 23.72%)
Min total-odr4-16 689.00 ( 0.00%) 529.00 ( 23.22%)
Min total-odr4-32 683.00 ( 0.00%) 528.00 ( 22.69%)
Min total-odr4-64 692.00 ( 0.00%) 531.00 ( 23.27%)
Min total-odr4-128 713.00 ( 0.00%) 556.00 ( 22.02%)
Min total-odr4-256 738.00 ( 0.00%) 586.00 ( 20.60%)
Min total-odr4-512 753.00 ( 0.00%) 595.00 ( 20.98%)
Min total-odr4-1024 752.00 ( 0.00%) 600.00 ( 20.21%)
This patch (of 27):
order-0 pages by definition cannot be compound so avoid the check in the
fast path for those pages.
[akpm@linux-foundation.org: use unlikely(order) in free_pages_prepare(), per Vlastimil]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Michal Hocko
|
3da88fb3ba |
mm, oom: move GFP_NOFS check to out_of_memory
__alloc_pages_may_oom is the central place to decide when the
out_of_memory should be invoked. This is a good approach for most
checks there because they are page allocator specific and the allocation
fails right after for all of them.
The notable exception is GFP_NOFS context which is faking
did_some_progress and keep the page allocator looping even though there
couldn't have been any progress from the OOM killer. This patch doesn't
change this behavior because we are not ready to allow those allocation
requests to fail yet (and maybe we will face the reality that we will
never manage to safely fail these request). Instead __GFP_FS check is
moved down to out_of_memory and prevent from OOM victim selection there.
There are two reasons for that
- OOM notifiers might release some memory even from this context
as none of the registered notifier seems to be FS related
- this might help a dying thread to get an access to memory
reserves and move on which will make the behavior more
consistent with the case when the task gets killed from a
different context.
Keep a comment in __alloc_pages_may_oom to make sure we do not forget
how GFP_NOFS is special and that we really want to do something about
it.
Note to the current oom_notifier users:
The observable difference for you is that oom notifiers cannot depend on
any fs locks because we could deadlock. Not that this would be allowed
today because that would just lockup machine in most of the cases and
ruling out the OOM killer along the way. Another difference is that
callbacks might be invoked sooner now because GFP_NOFS is a weaker
reclaim context and so there could be reclaimable memory which is just
not reachable now. That would require GFP_NOFS only loads which are
really rare and more importantly the observable result would be dropping
of reconstructible object and potential performance drop which is not
such a big deal when we are struggling to fulfill other important
allocation requests.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Raushaniya Maksudova <rmaksudova@parallels.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Joonsoo Kim
|
fc2bd799c7 |
mm/page_alloc: correct highmem memory statistics
ZONE_MOVABLE could be treated as highmem so we need to consider it for accurate statistics. And, in following patches, ZONE_CMA will be introduced and it can be treated as highmem, too. So, instead of manually adding stat of ZONE_MOVABLE, looping all zones and check whether the zone is highmem or not and add stat of the zone which can be treated as highmem. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
ba6b0979e3 |
power: add zone range overlapping check
There is a system thats node's pfns are overlapped as follows: -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to care this overlapping when iterating pfn range. mark_free_pages() iterates requested zone's pfn range and unset all range's bitmap first. And then it marks freepages in a zone to the bitmap. If there is an overlapping zone, above unset could clear previous marked bit and reference to this bitmap in the future will cause the problem. To prevent it, this patch adds a zone check in mark_free_pages(). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
b9eb63191a |
mm/memory_hotplug: add comment to some functions related to memory hotplug
__offline_isolated_pages() and test_pages_isolated() are used by memory hotplug. These functions require that range is in a single zone but there is no code to do this because memory hotplug checks it before calling these functions. To avoid confusing future user of these functions, this patch adds comments to them. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Li Zhang
|
949698a31a |
mm/page_alloc: Remove useless parameter of __free_pages_boot_core
__free_pages_boot_core has parameter pfn which is not used at all. Remove it. Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com> Reviewed-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
0139aa7b7f |
mm: rename _count, field of the struct page, to _refcount
Many developers already know that field for reference count of the struct page is _count and atomic type. They would try to handle it directly and this could break the purpose of page reference count tracepoint. To prevent direct _count modification, this patch rename it to _refcount and add warning message on the code. After that, developer who need to handle reference count will find that field should not be accessed directly. [akpm@linux-foundation.org: fix comments, per Vlastimil] [akpm@linux-foundation.org: Documentation/vm/transhuge.txt too] [sfr@canb.auug.org.au: sync ethernet driver changes] Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Sunil Goutham <sgoutham@cavium.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Manish Chopra <manish.chopra@qlogic.com> Cc: Yuval Mintz <yuval.mintz@qlogic.com> Cc: Tariq Toukan <tariqt@mellanox.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Jason Baron
|
bc22af74f2 |
mm: update min_free_kbytes from khugepaged after core initialization
Khugepaged attempts to raise min_free_kbytes if its set too low.
However, on boot khugepaged sets min_free_kbytes first from
subsys_initcall(), and then the mm 'core' over-rides min_free_kbytes
after from init_per_zone_wmark_min(), via a module_init() call.
Khugepaged used to use a late_initcall() to set min_free_kbytes (such
that it occurred after the core initialization), however this was
removed when the initialization of min_free_kbytes was integrated into
the starting of the khugepaged thread.
The fix here is simply to invoke the core initialization using a
core_initcall() instead of module_init(), such that the previous
initialization ordering is restored. I didn't restore the
late_initcall() since start_stop_khugepaged() already sets
min_free_kbytes via set_recommended_min_free_kbytes().
This was noticed when we had a number of page allocation failures when
moving a workload to a kernel with this new initialization ordering. On
an 8GB system this restores min_free_kbytes back to 67584 from 11365
when CONFIG_TRANSPARENT_HUGEPAGE=y is set and either
CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y or
CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y.
Fixes:
|
||
|
Vlastimil Babka
|
d9dddbf556 |
mm/page_alloc: prevent merging between isolated and other pageblocks
Hanjun Guo has reported that a CMA stress test causes broken accounting of CMA and free pages: > Before the test, I got: > -bash-4.3# cat /proc/meminfo | grep Cma > CmaTotal: 204800 kB > CmaFree: 195044 kB > > > After running the test: > -bash-4.3# cat /proc/meminfo | grep Cma > CmaTotal: 204800 kB > CmaFree: 6602584 kB > > So the freed CMA memory is more than total.. > > Also the the MemFree is more than mem total: > > -bash-4.3# cat /proc/meminfo > MemTotal: 16342016 kB > MemFree: 22367268 kB > MemAvailable: 22370528 kB Laura Abbott has confirmed the issue and suspected the freepage accounting rewrite around 3.18/4.0 by Joonsoo Kim. Joonsoo had a theory that this is caused by unexpected merging between MIGRATE_ISOLATE and MIGRATE_CMA pageblocks: > CMA isolates MAX_ORDER aligned blocks, but, during the process, > partialy isolated block exists. If MAX_ORDER is 11 and > pageblock_order is 9, two pageblocks make up MAX_ORDER > aligned block and I can think following scenario because pageblock > (un)isolation would be done one by one. > > (each character means one pageblock. 'C', 'I' means MIGRATE_CMA, > MIGRATE_ISOLATE, respectively. > > CC -> IC -> II (Isolation) > II -> CI -> CC (Un-isolation) > > If some pages are freed at this intermediate state such as IC or CI, > that page could be merged to the other page that is resident on > different type of pageblock and it will cause wrong freepage count. This was supposed to be prevented by CMA operating on MAX_ORDER blocks, but since it doesn't hold the zone->lock between pageblocks, a race window does exist. It's also likely that unexpected merging can occur between MIGRATE_ISOLATE and non-CMA pageblocks. This should be prevented in __free_one_page() since commit |
||
Tetsuo Handa
|
0a687aace3 |
mm,oom: do not loop !__GFP_FS allocation if the OOM killer is disabled
After the OOM killer is disabled during suspend operation, any !__GFP_NOFAIL && __GFP_FS allocations are forced to fail. Thus, any !__GFP_NOFAIL && !__GFP_FS allocations should be forced to fail as well. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Li Zhang
|
987b3095c2 |
mm: meminit: initialise more memory for inode/dentry hash tables in early boot
Upstream has supported page parallel initialisation for X86 and the boot
time is improved greately. Some tests have been done for Power.
Here is the result I have done with different memory size.
* 4GB memory:
boot time is as the following:
with patch vs without patch: 10.4s vs 24.5s
boot time is improved 57%
* 200GB memory:
boot time looks the same with and without patches.
boot time is about 38s
* 32TB memory:
boot time looks the same with and without patches
boot time is about 160s.
The boot time is much shorter than X86 with 24TB memory.
From community discussion, it costs about 694s for X86 24T system.
Parallel initialisation improves the performance by deferring memory
initilisation to kswap with N kthreads, it should improve the performance
therotically.
In testing on X86, performance is improved greatly with huge memory. But
on Power platform, it is improved greatly with less than 100GB memory.
For huge memory, it is not improved greatly. But it saves the time with
several threads at least, as the following information shows(32TB system
log):
[ 22.648169] node 9 initialised, 16607461 pages in 280ms
[ 22.783772] node 3 initialised, 23937243 pages in 410ms
[ 22.858877] node 6 initialised, 29179347 pages in 490ms
[ 22.863252] node 2 initialised, 29179347 pages in 490ms
[ 22.907545] node 0 initialised, 32049614 pages in 540ms
[ 22.920891] node 15 initialised, 32212280 pages in 550ms
[ 22.923236] node 4 initialised, 32306127 pages in 550ms
[ 22.923384] node 12 initialised, 32314319 pages in 550ms
[ 22.924754] node 8 initialised, 32314319 pages in 550ms
[ 22.940780] node 13 initialised, 33353677 pages in 570ms
[ 22.940796] node 11 initialised, 33353677 pages in 570ms
[ 22.941700] node 5 initialised, 33353677 pages in 570ms
[ 22.941721] node 10 initialised, 33353677 pages in 570ms
[ 22.941876] node 7 initialised, 33353677 pages in 570ms
[ 22.944946] node 14 initialised, 33353677 pages in 570ms
[ 22.946063] node 1 initialised, 33345485 pages in 580ms
It saves the time about 550*16 ms at least, although it can be ignore to
compare the boot time about 160 seconds. What's more, the boot time is
much shorter on Power even without patches than x86 for huge memory
machine.
So this patchset is still necessary to be enabled for Power.
This patch (of 2):
This patch is based on Mel Gorman's old patch in the mailing list,
https://lkml.org/lkml/2015/5/5/280 which is discussed but it is fixed with
a completion to wait for all memory initialised in page_alloc_init_late().
It is to fix the OOM problem on X86 with 24TB memory which allocates
memory in late initialisation. But for Power platform with 32TB memory,
it causes a call trace in vfs_caches_init->inode_init() and inode hash
table needs more memory. So this patch allocates 1GB for 0.25TB/node for
large system as it is mentioned in https://lkml.org/lkml/2015/5/1/627
This call trace is found on Power with 32TB memory, 1024CPUs, 16nodes.
Currently, it only allocates 2GB*16=32GB for early initialisation. But
Dentry cache hash table needes 16GB and Inode cache hash table needs 16GB.
So the system have no enough memory for it. The log from dmesg as the
following:
Dentry cache hash table entries: 2147483648 (order: 18,17179869184 bytes)
vmalloc: allocation failure, allocated 16021913600 of 17179934720 bytes
swapper/0: page allocation failure: order:0,mode:0x2080020
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-0-ppc64
Call Trace:
.dump_stack+0xb4/0xb664 (unreliable)
.warn_alloc_failed+0x114/0x160
.__vmalloc_area_node+0x1a4/0x2b0
.__vmalloc_node_range+0xe4/0x110
.__vmalloc_node+0x40/0x50
.alloc_large_system_hash+0x134/0x2a4
.inode_init+0xa4/0xf0
.vfs_caches_init+0x80/0x144
.start_kernel+0x40c/0x4e0
start_here_common+0x20/0x4a4
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|