Fix a race on creating pdflush threads. Without the patch, it is possible
to create more than MAX_PDFLUSH_THREADS threads, and this has been
observed in practice on IO loaded SMP machines.
The fix involves moving the lock around to protect the check against the
thread count and correctly dealing with thread creation failure.
This fix also _mostly_ repairs a race condition on how quickly the threads
are created. The original intent was to create a pdflush thread (up to
the max allowed) every second. Without this patch is is possible to
create NCPUS pdflush threads concurrently. The 'mostly' caveat is because
an assumption is made that thread creation will be successful. If we fail
to create the thread, the miss is not considered fatal. (we will try
again in 1 second)
Signed-off-by: Peter W Morreale <pmorreale@novell.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a ptraced task is unlinked, we need to stop branch tracing for
that task.
Since the unlink is called with interrupts disabled, and we need
interrupts enabled to stop branch tracing, we defer the work.
Collect all branch tracing related stuff in a branch tracing context.
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144550.712401000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This eliminates a compiler warning:
mm/allocpercpu.c: In function 'free_percpu':
mm/allocpercpu.c:146: warning: passing argument 2 of '__percpu_depopulate_mask' discards qualifiers from pointer target type
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kmemtrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
kmemtrace: trace kfree() calls with NULL or zero-length objects
kmemtrace: small cleanups
kmemtrace: restore original tracing data binary format, improve ABI
kmemtrace: kmemtrace_alloc() must fill type_id
kmemtrace: use tracepoints
kmemtrace, rcu: don't include unnecessary headers, allow kmemtrace w/ tracepoints
kmemtrace, rcu: fix rcupreempt.c data structure dependencies
kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies
kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies
kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_unlzma.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_bunzip2.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_inflate.c
kmemtrace, squashfs: fix slab.h dependency problem in squasfs
kmemtrace, befs: fix slab.h dependency problem
kmemtrace, security: fix linux/key.h header file dependencies
kmemtrace, fs: fix linux/fdtable.h header file dependencies
kmemtrace, fs: uninline simple_transaction_set()
kmemtrace, fs, security: move alloc_secdata() and free_secdata() to linux/security.h
This makes sure that we never wait on async IO for sync requests, instead
of doing the split on writes vs reads.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the profiling information returns userspace IPs but no way
to correlate them to userspace code. Userspace could look into
/proc/$pid/maps but that might not be current or even present anymore
at the time of analyzing the IPs.
Therefore provide means to track the mmap information and provide it
in the output stream.
XXX: only covers mmap()/munmap(), mremap() and mprotect() are missing.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Orig-LKML-Reference: <20090330171023.417259499@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...
Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits)
cpumask: remove cpumask allocation from idle_balance, fix
numa, cpumask: move numa_node_id default implementation to topology.h, fix
cpumask: remove cpumask allocation from idle_balance
x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus
x86: cpumask: update 32-bit APM not to mug current->cpus_allowed
x86: microcode: cleanup
x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c
cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
numa, cpumask: move numa_node_id default implementation to topology.h
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
cpumask: remove x86 cpumask_t uses.
cpumask: use cpumask_var_t in uv_flush_tlb_others.
cpumask: remove cpumask_t assignment from vector_allocation_domain()
cpumask: make Xen use the new operators.
cpumask: clean up summit's send_IPI functions
cpumask: use new cpumask functions throughout x86
x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask
cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
x86: unify 32 and 64-bit node_to_cpumask_map
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
trivial: Update my email address
trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
trivial: Fix misspelling of "Celsius".
trivial: remove unused variable 'path' in alloc_file()
trivial: fix a pdlfush -> pdflush typo in comment
trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
trivial: wusb: Storage class should be before const qualifier
trivial: drivers/char/bsr.c: Storage class should be before const qualifier
trivial: h8300: Storage class should be before const qualifier
trivial: fix where cgroup documentation is not correctly referred to
trivial: Give the right path in Documentation example
trivial: MTD: remove EOL from MODULE_DESCRIPTION
trivial: Fix typo in bio_split()'s documentation
trivial: PWM: fix of #endif comment
trivial: fix typos/grammar errors in Kconfig texts
trivial: Fix misspelling of firmware
trivial: cgroups: documentation typo and spelling corrections
trivial: Update contact info for Jochen Hein
trivial: fix typo "resgister" -> "register"
...
This patch adds Kconfig and Makefile entries and exports to
VFS functions to be used by POHMELFS.
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a function to install a monitor on the page lock waitqueue for a particular
page, thus allowing the page being unlocked to be detected.
This is used by CacheFiles to detect read completion on a page in the backing
filesystem so that it can then copy the data to the waiting netfs page.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Recruit a page flag to aid in cache management. The following extra flag is
defined:
(1) PG_fscache (PG_private_2)
The marked page is backed by a local cache and is pinning resources in the
cache driver.
If PG_fscache is set, then things that checked for PG_private will now also
check for that. This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
The attached patch causes read_cache_pages() to release page-private data on a
page for which add_to_page_cache() fails. If the filler function fails, then
the problematic page is left attached to the pagecache (with appropriate flags
set, one presumes) and the remaining to-be-attached pages are invalidated and
discarded. This permits pages with caching references associated with them to
be cleaned up.
The invalidatepage() address space op is called (indirectly) to do the honours.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Impact: also output kfree(NULL) entries
This patch moves the trace_kfree() calls before the ZERO_OR_NULL_PTR
check so that we can trace call-sites that call kfree() with NULL many
times which might be an indication of a bug.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <1237971957.30175.18.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kmemtrace now uses tracepoints instead of markers. We no longer need to
use format specifiers to pass arguments.
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
[ folded: Use the new TP_PROTO and TP_ARGS to fix the build. ]
[ folded: fix build when CONFIG_KMEMTRACE is disabled. ]
[ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <ae61c0f37156db8ec8dc0d5778018edde60a92e3.1237813499.git.eduard.munteanu@linux360.ro>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
mm/failslab.c depends on slab.h without including it:
CC mm/failslab.o
mm/failslab.c: In function ‘should_failslab’:
mm/failslab.c:16: error: ‘__GFP_NOFAIL’ undeclared (first use in this function)
mm/failslab.c:16: error: (Each undeclared identifier is reported only once
mm/failslab.c:16: error: for each function it appears in.)
mm/failslab.c:19: error: ‘__GFP_WAIT’ undeclared (first use in this function)
make[1]: *** [mm/failslab.o] Error 1
make: *** [mm] Error 2
It gets included implicitly currently - but this will not be the
case with upcoming kmemtrace changes.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <1237888761.25315.69.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Current mem_cgroup_cache_charge is a bit complicated especially
in the case of shmem's swap-in.
This patch cleans it up by using try_charge_swapin and commit_charge_swapin.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's pointed out that swap_cgroup's message at swapon() is nonsense.
Because
* It can be calculated very easily if all necessary information is
written in Kconfig.
* It's not necessary to annoying people at every swapon().
In other view, now, memory usage per swp_entry is reduced to 2bytes from
8bytes(64bit) and I think it's reasonably small.
Reported-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine,
size of swap_cgroup goes down to 2 bytes from 8bytes.
This means, when 2GB of swap is equipped, (assume the page size is 4096bytes)
From size of swap_cgroup = 2G/4k * 8 = 4Mbytes.
To size of swap_cgroup = 2G/4k * 2 = 1Mbytes.
Reduction is large. Of course, there are trade-offs. This CSS ID will
add overhead to swap-in/swap-out/swap-free.
But in general,
- swap is a resource which the user tend to avoid use.
- If swap is never used, swap_cgroup area is not used.
- Reading traditional manuals, size of swap should be proportional to
size of memory. Memory size of machine is increasing now.
I think reducing size of swap_cgroup makes sense.
Note:
- ID->CSS lookup routine has no locks, it's under RCU-Read-Side.
- memcg can be obsolete at rmdir() but not freed while refcnt from
swap_cgroup is available.
Changelog v4->v5:
- reworked on to memcg-charge-swapcache-to-proper-memcg.patch
Changlog ->v4:
- fixed not configured case.
- deleted unnecessary comments.
- fixed NULL pointer bug.
- fixed message in dmesg.
[nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memcg_test.txt says at 4.1:
This swap-in is one of the most complicated work. In do_swap_page(),
following events occur when pte is unchanged.
(1) the page (SwapCache) is looked up.
(2) lock_page()
(3) try_charge_swapin()
(4) reuse_swap_page() (may call delete_swap_cache())
(5) commit_charge_swapin()
(6) swap_free().
Considering following situation for example.
(A) The page has not been charged before (2) and reuse_swap_page()
doesn't call delete_from_swap_cache().
(B) The page has not been charged before (2) and reuse_swap_page()
calls delete_from_swap_cache().
(C) The page has been charged before (2) and reuse_swap_page() doesn't
call delete_from_swap_cache().
(D) The page has been charged before (2) and reuse_swap_page() calls
delete_from_swap_cache().
memory.usage/memsw.usage changes to this page/swp_entry will be
Case (A) (B) (C) (D)
Event
Before (2) 0/ 1 0/ 1 1/ 1 1/ 1
===========================================
(3) +1/+1 +1/+1 +1/+1 +1/+1
(4) - 0/ 0 - -1/ 0
(5) 0/-1 0/ 0 -1/-1 0/ 0
(6) - 0/-1 - 0/-1
===========================================
Result 1/ 1 1/ 1 1/ 1 1/ 1
In any cases, charges to this page should be 1/ 1.
In case of (D), mem_cgroup_try_get_from_swapcache() returns NULL
(because lookup_swap_cgroup() returns NULL), so "+1/+1" at (3) means
charges to the memcg("foo") to which the "current" belongs.
OTOH, "-1/0" at (4) and "0/-1" at (6) means uncharges from the memcg("baa")
to which the page has been charged.
So, if the "foo" and "baa" is different(for example because of task move),
this charge will be moved from "baa" to "foo".
I think this is an unexpected behavior.
This patch fixes this by modifying mem_cgroup_try_get_from_swapcache()
to return the memcg to which the swapcache has been charged if PCG_USED bit
is set.
IIUC, checking PCG_USED bit of swapcache is safe under page lock.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, mem_cgroup_calc_mapped_ratio() is unused at all. it can be
removed and KAMEZAWA-san suggested it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add RSS and swap to OOM output from memcg
Display memcg values like failcnt, usage and limit when an OOM occurs due
to memcg.
Thanks to Johannes Weiner, Li Zefan, David Rientjes, Kamezawa Hiroyuki,
Daisuke Nishimura and KOSAKI Motohiro for review.
Sample output
-------------
Task in /a/x killed as a result of limit of /a
memory: usage 1048576kB, limit 1048576kB, failcnt 4183
memory+swap: usage 1400964kB, limit 9007199254740991kB, failcnt 0
[akpm@linux-foundation.org: compilation fix]
[akpm@linux-foundation.org: fix kerneldoc and whitespace]
[akpm@linux-foundation.org: add printk facility level]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch tries to fix OOM Killer problems caused by hierarchy.
Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to
kill a task in memcg.
But, when hierarchy is used, it's broken and correct task cannot
be killed. For example, in following cgroup
/groupA/ hierarchy=1, limit=1G,
01 nolimit
02 nolimit
All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to
groupA's 1Gbytes but OOM Killer just kills tasks in groupA.
This patch provides makes the bad process be selected from all tasks
under hierarchy. BTW, currently, oom_jiffies is updated against groupA
in above case. oom_jiffies of tree should be updated.
To see how oom_jiffies is used, please check mem_cgroup_oom_called()
callers.
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: const fix]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.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>
As pointed out, shrinking memcg's limit should return -EBUSY after
reasonable retries. This patch tries to fix the current behavior of
shrink_usage.
Before looking into "shrink should return -EBUSY" problem, we should fix
hierarchical reclaim code. It compares current usage and current limit,
but it only makes sense when the kernel reclaims memory because hit
limits. This is also a problem.
What this patch does are.
1. add new argument "shrink" to hierarchical reclaim. If "shrink==true",
hierarchical reclaim returns immediately and the caller checks the kernel
should shrink more or not.
(At shrinking memory, usage is always smaller than limit. So check for
usage < limit is useless.)
2. For adjusting to above change, 2 changes in "shrink"'s retry path.
2-a. retry_count depends on # of children because the kernel visits
the children under hierarchy one by one.
2-b. rather than checking return value of hierarchical_reclaim's progress,
compares usage-before-shrink and usage-after-shrink.
If usage-before-shrink <= usage-after-shrink, retry_count is
decremented.
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.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>
Clean up memory.stat file routine and show "total" hierarchical stat.
This patch does
- renamed get_all_zonestat to be get_local_zonestat.
- remove old mem_cgroup_stat_desc, which is only for per-cpu stat.
- add mcs_stat to cover both of per-cpu/per-lru stat.
- add "total" stat of hierarchy (*)
- add a callback system to scan all memcg under a root.
== "total" is added.
[kamezawa@localhost ~]$ cat /opt/cgroup/xxx/memory.stat
cache 0
rss 0
pgpgin 0
pgpgout 0
inactive_anon 0
active_anon 0
inactive_file 0
active_file 0
unevictable 0
hierarchical_memory_limit 50331648
hierarchical_memsw_limit 9223372036854775807
total_cache 65536
total_rss 192512
total_pgpgin 218
total_pgpgout 155
total_inactive_anon 0
total_active_anon 135168
total_inactive_file 61440
total_active_file 4096
total_unevictable 0
==
(*) maybe the user can do calc hierarchical stat by his own program
in userland but if it can be written in clean way, it's worth to be
shown, I think.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.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>
Assigning CSS ID for each memcg and use css_get_next() for scanning hierarchy.
Assume folloing tree.
group_A (ID=3)
/01 (ID=4)
/0A (ID=7)
/02 (ID=10)
group_B (ID=5)
and task in group_A/01/0A hits limit at group_A.
reclaim will be done in following order (round-robin).
group_A(3) -> group_A/01 (4) -> group_A/01/0A (7) -> group_A/02(10)
-> group_A -> .....
Round robin by ID. The last visited cgroup is recorded and restart
from it when it start reclaim again.
(More smart algorithm can be implemented..)
No cgroup_mutex or hierarchy_mutex is required.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.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>
In following situation, with memory subsystem,
/groupA use_hierarchy==1
/01 some tasks
/02 some tasks
/03 some tasks
/04 empty
When tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim
is triggered and the kernel walks tree under groupA. In this case,
rmdir /groupA/04 fails with -EBUSY frequently because of temporal
refcnt from the kernel.
In general. cgroup can be rmdir'd if there are no children groups and
no tasks. Frequent fails of rmdir() is not useful to users.
(And the reason for -EBUSY is unknown to users.....in most cases)
This patch tries to modify above behavior, by
- retries if css_refcnt is got by someone.
- add "return value" to pre_destroy() and allows subsystem to
say "we're really busy!"
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is a fairly common operation to have a pointer to a work and to need a
pointer to the delayed work it is contained in. In particular, all
delayed works which want to rearm themselves will have to do that. So it
would seem fair to offer a helper function for this operation.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The calculation of the value nr in do_xip_mapping_read is incorrect. If
the copy required more than one iteration in the do while loop the copies
variable will be non-zero. The maximum length that may be passed to the
call to copy_to_user(buf+copied, xip_mem+offset, nr) is len-copied but the
check only compares against (nr > len).
This bug is the cause for the heap corruption Carsten has been chasing
for so long:
*** glibc detected *** /bin/bash: free(): invalid next size (normal): 0x00000000800e39f0 ***
======= Backtrace: =========
/lib64/libc.so.6[0x200000b9b44]
/lib64/libc.so.6(cfree+0x8e)[0x200000bdade]
/bin/bash(free_buffered_stream+0x32)[0x80050e4e]
/bin/bash(close_buffered_stream+0x1c)[0x80050ea4]
/bin/bash(unset_bash_input+0x2a)[0x8001c366]
/bin/bash(make_child+0x1d4)[0x8004115c]
/bin/bash[0x8002fc3c]
/bin/bash(execute_command_internal+0x656)[0x8003048e]
/bin/bash(execute_command+0x5e)[0x80031e1e]
/bin/bash(execute_command_internal+0x79a)[0x800305d2]
/bin/bash(execute_command+0x5e)[0x80031e1e]
/bin/bash(reader_loop+0x270)[0x8001efe0]
/bin/bash(main+0x1328)[0x8001e960]
/lib64/libc.so.6(__libc_start_main+0x100)[0x200000592a8]
/bin/bash(clearerr+0x5e)[0x8001c092]
With this bug fix the commit 0e4a9b5928
"ext2/xip: refuse to change xip flag during remount with busy inodes" can
be removed again.
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Even though vmstat_work is marked deferrable, there are still benefits to
aligning it. For certain applications we want to keep OS jitter as low as
possible and aligning timers and work so they occur together can reduce
their overall impact.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a number of issues with the per-MM VMA patch:
(1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
a NOMMU system with more than 2G pages. Makes no difference on a 32-bit
system.
(2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
lest it overflow.
(3) Move the allocation of the vm_area_struct slab back for fork.c.
(4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.
(5) Use BUG_ON() rather than if () BUG().
(6) Make the default validate_nommu_regions() a static inline rather than a
#define.
(7) Make free_page_series()'s objection to pages with a refcount != 1 more
informative.
(8) Adjust the __put_nommu_region() banner comment to indicate that the
semaphore must be held for writing.
(9) Limit the number of warnings about munmaps of non-mmapped regions.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a build failure with generic debug pagealloc:
mm/debug-pagealloc.c: In function 'set_page_poison':
mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: In function 'clear_page_poison':
mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: In function 'page_poison':
mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: At top level:
mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
include/linux/mm.h:1278: error: previous definition of 'kernel_map_pages' was here
mm/debug-pagealloc.c: In function 'kernel_map_pages':
mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared (first use in this function)
by fixing
- debug_flags should be in struct page
- define DEBUG_PAGEALLOC config option for all architectures
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Synopsis: if shmem_writepage calls swap_writepage directly, most shmem
swap loads benefit, and a catastrophic interaction between SLUB and some
flash storage is avoided.
shmem_writepage() has always been peculiar in making no attempt to write:
it has just transferred a shmem page from file cache to swap cache, then
let that page make its way around the LRU again before being written and
freed.
The idea was that people use tmpfs because they want those pages to stay
in RAM; so although we give it an overflow to swap, we should resist
writing too soon, giving those pages a second chance before they can be
reclaimed.
That was always questionable, and I've toyed with this patch for years;
but never had a clear justification to depart from the original design.
It became more questionable in 2.6.28, when the split LRU patches classed
shmem and tmpfs pages as SwapBacked rather than as file_cache: that in
itself gives them more resistance to reclaim than normal file pages. I
prepared this patch for 2.6.29, but the merge window arrived before I'd
completed gathering statistics to justify sending it in.
Then while comparing SLQB against SLUB, running SLUB on a laptop I'd
habitually used with SLAB, I found SLUB to run my tmpfs kbuild swapping
tests five times slower than SLAB or SLQB - other machines slower too, but
nowhere near so bad. Simpler "cp -a" swapping tests showed the same.
slub_max_order=0 brings sanity to all, but heavy swapping is too far from
normal to justify such a tuning. The crucial factor on that laptop turns
out to be that I'm using an SD card for swap. What happens is this:
By default, SLUB uses order-2 pages for shmem_inode_cache (and many other
fs inodes), so creating tmpfs files under memory pressure brings lumpy
reclaim into play. One subpage of the order is chosen from the bottom of
the LRU as usual, then the other three picked out from their random
positions on the LRUs.
In a tmpfs load, many of these pages will be ones which already passed
through shmem_writepage, so already have swap allocated. And though their
offsets on swap were probably allocated sequentially, now that the pages
are picked off at random, their swap offsets are scattered.
But the flash storage on the SD card is very sensitive to having its
writes merged: once swap is written at scattered offsets, performance
falls apart. Rotating disk seeks increase too, but less disastrously.
So: stop giving shmem/tmpfs pages a second pass around the LRU, write them
out to swap as soon as their swap has been allocated.
It's surely possible to devise an artificial load which runs faster the
old way, one whose sizing is such that the tmpfs pages on their second
pass are the ones that are wanted again, and other pages not.
But I've not yet found such a load: on all machines, under the loads I've
tried, immediate swap_writepage speeds up shmem swapping: especially when
using the SLUB allocator (and more effectively than slub_max_order=0), but
also with the others; and it also reduces the variance between runs. How
much faster varies widely: a factor of five is rare, 5% is common.
One load which might have suffered: imagine a swapping shmem load in a
limited mem_cgroup on a machine with plenty of memory. Before 2.6.29 the
swapcache was not charged, and such a load would have run quickest with
the shmem swapcache never written to swap. But now swapcache is charged,
so even this load benefits from shmem_writepage directly to swap.
Apologies for the #ifndef CONFIG_SWAP swap_writepage() stub in swap.h:
it's silly because that will never get called; but refactoring shmem.c
sensibly according to CONFIG_SWAP will be a separate task.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
try_to_free_pages() is used for the direct reclaim of up to
SWAP_CLUSTER_MAX pages when watermarks are low. The caller to
alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to
be used but this is not passed to try_to_free_pages(). This can lead to
unnecessary reclaim of pages that are unusable by the caller and int the
worst case lead to allocation failure as progress was not been make where
it is needed.
This patch passes the nodemask used for alloc_pages_nodemask() to
try_to_free_pages().
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a shrinker has a negative number of objects to delete, the symbol
name of the shrinker should be printed, not shrink_slab. This also makes
the error message slightly more informative.
Cc: Ingo Molnar <mingo@elte.hu>
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>
Make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=n. There's no logical
reason it shouldn't be available, and it can be used for ramfs.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Enrik Berkhan <Enrik.Berkhan@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mlock() facility does not exist for NOMMU since all mappings are
effectively locked anyway, so we don't make the bits available when
they're not useful.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Enrik Berkhan <Enrik.Berkhan@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86 has debug_kmap_atomic_prot() which is error checking function for
kmap_atomic. It is usefull for the other architectures, although it needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.
This patch exposes it to the other architectures.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags. There should be no functional change.
This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg. virtual_address to the
driver, which might be important in some special cases).
This is required for a subsequent fix. And will also make it easier to
merge page_mkwrite() with fault() in future.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9838
On i386, HZ=1000, jiffies_to_clock_t() converts time in a somewhat strange
way from the user's point of view:
# echo 500 >/proc/sys/vm/dirty_writeback_centisecs
# cat /proc/sys/vm/dirty_writeback_centisecs
499
So, we have 5000 jiffies converted to only 499 clock ticks and reported
back.
TICK_NSEC = 999848
ACTHZ = 256039
Keeping in-kernel variable in units passed from userspace will fix issue
of course, but this probably won't be right for every sysctl.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390. This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().
This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I notice there are many places doing copy_from_user() which follows
kmalloc():
dst = kmalloc(len, GFP_KERNEL);
if (!dst)
return -ENOMEM;
if (copy_from_user(dst, src, len)) {
kfree(dst);
return -EFAULT
}
memdup_user() is a wrapper of the above code. With this new function, we
don't have to write 'len' twice, which can lead to typos/mistakes. It
also produces smaller code and kernel text.
A quick grep shows 250+ places where memdup_user() *may* be used. I'll
prepare a patchset to do this conversion.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
chg is unsigned, so it cannot be less than 0.
Also, since region_chg returns long, let vma_needs_reservation() forward
this to alloc_huge_page(). Store it as long as well. all callers cast it
to long anyway.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pagevec_swap_free() at the end of shrink_active_list() was introduced
in 68a22394 "vmscan: free swap space on swap-in/activation" when
shrink_active_list() was still rotating referenced active pages.
In 7e9cd48 "vmscan: fix pagecache reclaim referenced bit check" this was
changed, the rotating removed but the pagevec_swap_free() after the
rotation loop was forgotten, applying now to the pagevec of the
deactivation loop instead.
Now swap space is freed for deactivated pages. And only for those that
happen to be on the pagevec after the deactivation loop.
Complete 7e9cd48 and remove the rest of the swap freeing.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In shrink_active_list() after the deactivation loop, we strip buffer heads
from the potentially remaining pages in the pagevec.
Currently, this drops the zone's lru lock for stripping, only to reacquire
it again afterwards to update statistics.
It is not necessary to strip the pages before updating the stats, so move
the whole thing out of the protected region and save the extra locking.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a helper function account_page_dirtied(). Use that from two
callsites. reiser4 adds a function which adds a third callsite.
Signed-off-by: Edward Shishkin<edward.shishkin@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During page allocation, there are two stages of direct reclaim that are
applied to each zone in the preferred list. The first stage using
zone_reclaim() reclaims unmapped file backed pages and slab pages if over
defined limits as these are cheaper to reclaim. The caller specifies the
order of the target allocation but the scan control is not being correctly
initialised.
The impact is that the correct number of pages are being reclaimed but
that lumpy reclaim is not being applied. This increases the chances of a
full direct reclaim via try_to_free_pages() is required.
This patch initialises the order field of the scan control as requested by
the caller.
[mel@csn.ul.ie: rewrote changelog]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At first look, mark_page_accessed() in follow_page() seems a bit strange.
It seems pte_mkyoung() would be better consistent with other kernel code.
However, it is intentional. The commit log said:
------------------------------------------------
commit 9e45f61d69be9024a2e6bef3831fb04d90fac7a8
Author: akpm <akpm>
Date: Fri Aug 15 07:24:59 2003 +0000
[PATCH] Use mark_page_accessed() in follow_page()
Touching a page via follow_page() counts as a reference so we should be
either setting the referenced bit in the pte or running mark_page_accessed().
Altering the pte is tricky because we haven't implemented an atomic
pte_mkyoung(). And mark_page_accessed() is better anyway because it has more
aging state: it can move the page onto the active list.
BKrev: 3f3c8acbplT8FbwBVGtth7QmnqWkIw
------------------------------------------------
The atomic issue is still true nowadays. adding comment help to understand
code intention and it would be better.
[akpm@linux-foundation.org: clarify text]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shrink_inactive_list() scans in sc->swap_cluster_max chunks until it hits
the scan limit it was passed.
shrink_inactive_list()
{
do {
isolate_pages(swap_cluster_max)
shrink_page_list()
} while (nr_scanned < max_scan);
}
This assumes that swap_cluster_max is not bigger than the scan limit
because the latter is checked only after at least one iteration.
In shrink_all_memory() sc->swap_cluster_max is initialized to the overall
reclaim goal in the beginning but not decreased while reclaim is making
progress which leads to subsequent calls to shrink_inactive_list()
reclaiming way too much in the one iteration that is done unconditionally.
Set sc->swap_cluster_max always to the proper goal before doing
shrink_all_zones()
shrink_list()
shrink_inactive_list().
While the current shrink_all_memory() happily reclaims more than actually
requested, this patch fixes it to never exceed the goal:
unpatched
wanted=10000 reclaimed=13356
wanted=10000 reclaimed=19711
wanted=10000 reclaimed=10289
wanted=10000 reclaimed=17306
wanted=10000 reclaimed=10700
wanted=10000 reclaimed=10004
wanted=10000 reclaimed=13301
wanted=10000 reclaimed=10976
wanted=10000 reclaimed=10605
wanted=10000 reclaimed=10088
wanted=10000 reclaimed=15000
patched
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=9599
wanted=10000 reclaimed=8476
wanted=10000 reclaimed=8326
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=9919
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=9624
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=8500 reclaimed=8092
wanted=316 reclaimed=316
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: MinChan Kim <minchan.kim@gmail.com>
Acked-by: Nigel Cunningham <ncunningham@crca.org.au>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a79311c14e "vmscan: bail out of
direct reclaim after swap_cluster_max pages" moved the nr_reclaimed
counter into the scan control to accumulate the number of all reclaimed
pages in a reclaim invocation.
shrink_all_memory() can use the same mechanism. it increase code
consistency and redability.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit bf3f3bc5e7 (mm: don't
mark_page_accessed in fault path) only remove the mark_page_accessed() in
filemap_fault().
Therefore, swap-backed pages and file-backed pages have inconsistent
behavior. mark_page_accessed() should be removed from do_swap_page().
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: cleanup
In almost cases, for_each_zone() is used with populated_zone(). It's
because almost function doesn't need memoryless node information.
Therefore, for_each_populated_zone() can help to make code simplify.
This patch has no functional change.
[akpm@linux-foundation.org: small cleanup]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sc.may_swap does not only influence reclaiming of anon pages but pages
mapped into pagetables in general, which also includes mapped file pages.
In shrink_page_list():
if (!sc->may_swap && page_mapped(page))
goto keep_locked;
For anon pages, this makes sense as they are always mapped and reclaiming
them always requires swapping.
But mapped file pages are skipped here as well and it has nothing to do
with swapping.
The real effect of the knob is whether mapped pages are unmapped and
reclaimed or not. Rename it to `may_unmap' to have its name match its
actual meaning more precisely.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: MinChan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no need to call for int_sqrt if argument is 0.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
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>
vmap's dirty_list is unused. It's for optimizing flushing. but Nick
didn't write the code yet. so, we don't need it until time as it is
needed.
This patch removes vmap_block's dirty_list and codes related to it.
Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case if start_pfn overlap the upper bound no need to test end_pfn again
since we have it already trimmed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: build fix
fix typo in mm/slob.c:
mm/slob.c:469: error: ‘flags’ undeclared (first use in this function)
mm/slob.c:469: error: (Each undeclared identifier is reported only once
mm/slob.c:469: error: for each function it appears in.)
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090128135457.350751756@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-stage-3-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (190 commits)
Revert "cpuacct: reduce one NULL check in fast-path"
Revert "x86: don't compile vsmp_64 for 32bit"
x86: Correct behaviour of irq affinity
x86: early_ioremap_init(), use __fix_to_virt(), because we are sure it's safe
x86: use default_cpu_mask_to_apicid for 64bit
x86: fix set_extra_move_desc calling
x86, PAT, PCI: Change vma prot in pci_mmap to reflect inherited prot
x86/dmi: fix dmi_alloc() section mismatches
x86: e820 fix various signedness issues in setup.c and e820.c
x86: apic/io_apic.c define msi_ir_chip and ir_ioapic_chip all the time
x86: irq.c keep CONFIG_X86_LOCAL_APIC interrupts together
x86: irq.c use same path for show_interrupts
x86: cpu/cpu.h cleanup
x86: Fix a couple of sparse warnings in arch/x86/kernel/apic/io_apic.c
Revert "x86: create a non-zero sized bm_pte only when needed"
x86: pci-nommu.c cleanup
x86: io_delay.c cleanup
x86: rtc.c cleanup
x86: i8253 cleanup
x86: kdebugfs.c cleanup
...
It doesn't change the semantics, but it looks like
the logical 'or' was meant to be used here.
Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Impact: cleanup
Time to clean up remaining laggards using the old cpu_ functions.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Trond.Myklebust@netapp.com
Impact: cleanup
(Thanks to Al Viro for reminding me of this, via Ingo)
CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:
#define CPU_MASK_ALL (cpumask_t) { { ... } }
Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:
#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
Which formalizes this practice. One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).
So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
with the modern "cpu_all_mask" (a real const struct cpumask *).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mike Travis <travis@sgi.com>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (422 commits)
[ARM] 5435/1: fix compile warning in sanity_check_meminfo()
[ARM] 5434/1: ARM: OMAP: Fix mailbox compile for 24xx
[ARM] pxa: fix the bad assumption that PCMCIA sockets always start with 0
[ARM] pxa: fix Colibri PXA300 and PXA320 LCD backlight pins
imxfb: Fix TFT mode
i.MX21/27: remove ifdef CONFIG_FB_IMX
imxfb: add clock support
mxc: add arch_reset() function
clkdev: add possibility to get a clock based on the device name
i.MX1: remove fb support from mach-imx
[ARM] pxa: build arch/arm/plat-pxa/mfp.c only when PXA3xx or ARCH_MMP defined
Gemini: Add support for Teltonika RUT100
Gemini: gpiolib based GPIO support v2
MAINTAINERS: add myself as Gemini architecture maintainer
ARM: Add Gemini architecture v3
[ARM] OMAP: Fix compile for omap2_init_common_hw()
MAINTAINERS: Add myself as Faraday ARM core variant maintainer
ARM: Add support for FA526 v2
[ARM] acorn,ebsa110,footbridge,integrator,sa1100: Convert asm/io.h to linux/io.h
[ARM] collie: fix two minor formatting nits
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
slob: fix lockup in slob_free()
slub: use get_track()
slub: rename calculate_min_partial() to set_min_partial()
slub: add min_partial sysfs tunable
slub: move min_partial to struct kmem_cache
SLUB: Fix default slab order for big object sizes
SLUB: Do not pass 8k objects through to the page allocator
SLUB: Introduce and use SLUB_MAX_SIZE and SLUB_PAGE_SHIFT constants
slob: clean up the code
SLUB: Use ->objsize from struct kmem_cache_cpu in slab_free()
* 'for-2.6.30' of git://git.kernel.dk/linux-2.6-block:
Get rid of pdflush_operation() in emergency sync and remount
btrfs: get rid of current_is_pdflush() in btrfs_btree_balance_dirty
Move the default_backing_dev_info out of readahead.c and into backing-dev.c
block: Repeated lines in switching-sched.txt
bsg: Remove bogus check against request_queue->max_sectors
block: WARN in __blk_put_request() for potential bio leak
loop: fix circular locking in loop_clr_fd()
loop: support barrier writes
bsg: add support for tail queuing
cpqarray: enable bus mastering
block: genhd.h cleanup patch
block: add private bio_set for bio integrity allocations
block: genhd.h comment needs updating
block: get rid of unused blkdev_free_rq() define
block: remove various blk_queue_*() setting functions in blk_init_queue_node()
cciss: add BUILD_BUG_ON() for catching bad CommandList_struct alignment
block: don't create bio_vec slabs of less than the inline number
block: cleanup bio_alloc_bioset()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (71 commits)
SELinux: inode_doinit_with_dentry drop no dentry printk
SELinux: new permission between tty audit and audit socket
SELinux: open perm for sock files
smack: fixes for unlabeled host support
keys: make procfiles per-user-namespace
keys: skip keys from another user namespace
keys: consider user namespace in key_permission
keys: distinguish per-uid keys in different namespaces
integrity: ima iint radix_tree_lookup locking fix
TOMOYO: Do not call tomoyo_realpath_init unless registered.
integrity: ima scatterlist bug fix
smack: fix lots of kernel-doc notation
TOMOYO: Don't create securityfs entries unless registered.
TOMOYO: Fix exception policy read failure.
SELinux: convert the avc cache hash list to an hlist
SELinux: code readability with avc_cache
SELinux: remove unused av.decided field
SELinux: more careful use of avd in avc_has_perm_noaudit
SELinux: remove the unused ae.used
SELinux: check seqno when updating an avc_node
...
Enlarge default dirty ratios from 5/10 to 10/20. This fixes [Bug
#12809] iozone regression with 2.6.29-rc6.
The iozone benchmarks are performed on a 1200M file, with 8GB ram.
iozone -i 0 -i 1 -i 2 -i 3 -i 4 -r 4k -s 64k -s 512m -s 1200m -b tmp.xls
iozone -B -r 4k -s 64k -s 512m -s 1200m -b tmp.xls
The performance regression is triggered by commit 1cf6e7d83bf3(mm: task
dirty accounting fix), which makes more correct/thorough dirty
accounting.
The default 5/10 dirty ratios were picked (a) with the old dirty logic
and (b) largely at random and (c) designed to be aggressive. In
particular, that (a) means that having fixed some of the dirty
accounting, maybe the real bug is now that it was always too aggressive,
just hidden by an accounting issue.
The enlarged 10/20 dirty ratios are just about enough to fix the regression.
[ We will have to look at how this affects the old fsync() latency issue,
but that probably will need independent work. - Linus ]
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: "Lin, Ming M" <ming.m.lin@intel.com>
Tested-by: "Lin, Ming M" <ming.m.lin@intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't hold SLOB lock when freeing the page. Reduces lock hold width. See
the following thread for discussion of the bug:
http://marc.info/?l=linux-kernel&m=123709983214143&w=2
Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Use get_track() in set_track()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Impact: build fix on SH !CONFIG_MMU
Stephen Rothwell reported this linux-next build failure on the SH
architecture:
kernel/built-in.o: In function `disable_all_kprobes':
kernel/kprobes.c:1382: undefined reference to `text_mutex'
[...]
And observed:
| Introduced by commit 4460fdad85 ("tracing,
| Text Edit Lock - kprobes architecture independent support") from the
| tracing tree. text_mutex is defined in mm/memory.c which is only built
| if CONFIG_MMU is defined, which is not true for sh allmodconfig.
Move this lock to kernel/extable.c (which is already home to various
kernel text related routines), which file is always built-in.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <20090320110602.86351a91.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Most ARM machines have a non IO coherent cache, meaning that the
dma_map_*() set of functions must clean and/or invalidate the affected
memory manually before DMA occurs. And because the majority of those
machines have a VIVT cache, the cache maintenance operations must be
performed using virtual
addresses.
When a highmem page is kunmap'd, its mapping (and cache) remains in place
in case it is kmap'd again. However if dma_map_page() is then called with
such a page, some cache maintenance on the remaining mapping must be
performed. In that case, page_address(page) is non null and we can use
that to synchronize the cache.
It is unlikely but still possible for kmap() to race and recycle the
virtual address obtained above, and use it for another page before some
on-going cache invalidation loop in dma_map_page() is done. In that case,
the new mapping could end up with dirty cache lines for another page,
and the unsuspecting cache invalidation loop in dma_map_page() might
simply discard those dirty cache lines resulting in data loss.
For example, let's consider this sequence of events:
- dma_map_page(..., DMA_FROM_DEVICE) is called on a highmem page.
--> - vaddr = page_address(page) is non null. In this case
it is likely that the page has valid cache lines
associated with vaddr. Remember that the cache is VIVT.
--> for (i = vaddr; i < vaddr + PAGE_SIZE; i += 32)
invalidate_cache_line(i);
*** preemption occurs in the middle of the loop above ***
- kmap_high() is called for a different page.
--> - last_pkmap_nr wraps to zero and flush_all_zero_pkmaps()
is called. The pkmap_count value for the page passed
to dma_map_page() above happens to be 1, so the page
is unmapped. But prior to that, flush_cache_kmaps()
cleared the cache for it. So far so good.
- A fresh pkmap entry is assigned for this kmap request.
The Murphy law says this pkmap entry will eventually
happen to use the same vaddr as the one which used to
belong to the other page being processed by
dma_map_page() in the preempted thread above.
- The kmap_high() caller start dirtying the cache using the
just assigned virtual mapping for its page.
*** the first thread is rescheduled ***
- The for(...) loop is resumed, but now cached
data belonging to a different physical page is
being discarded !
And this is not only a preemption issue as ARM can be SMP as well,
making the above scenario just as likely. Hence the need for some kind
of pkmap page pinning which can be used in any context, primarily for
the benefit of dma_map_page() on ARM.
This provides the necessary interface to cope with the above issue if
ARCH_NEEDS_KMAP_HIGH_GET is defined, otherwise the resulting code is
unchanged.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Reviewed-by: MinChan Kim <minchan.kim@gmail.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Impact: cleanup
Add a new vm flag VM_PFN_AT_MMAP to identify a PFNMAP that is
fully mapped with remap_pfn_range. Patch removes the overloading
of VM_INSERTPAGE from the earlier patch.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Nick Piggin <npiggin@suse.de>
LKML-Reference: <20090313233543.GA19909@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
node_to_cpumask (and the blecherous node_to_cpumask_ptr which
contained a declaration) are replaced now everyone implements
cpumask_of_node.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: fix false positive PAT warnings - also fix VirtalBox hang
Use of vma->vm_pgoff to identify the pfnmaps that are fully
mapped at mmap time is broken. vm_pgoff is set by generic mmap
code even for cases where drivers are setting up the mappings
at the fault time.
The problem was originally reported here:
http://marc.info/?l=linux-kernel&m=123383810628583&w=2
Change is_linear_pfn_mapping logic to overload VM_INSERTPAGE
flag along with VM_PFNMAP to mean full PFNMAP setup at mmap
time.
Problem also tracked at:
http://bugzilla.kernel.org/show_bug.cgi?id=12800
Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha>@intel.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: "ebiederm@xmission.com" <ebiederm@xmission.com>
Cc: <stable@kernel.org> # only for 2.6.29.1, not .28
LKML-Reference: <20090313004527.GA7176@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Even when page reclaim is under mem_cgroup, # of scan page is determined by
status of global LRU. Fix that.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: remove spurious WARN on legacy SMP percpu allocator
Commit f2a8205c4e incorrectly added too
tight WARN_ON_ONCE() on alignments for UP and legacy SMP percpu
allocator. Commit e317603694 fixed it
for UP but legacy SMP allocator was forgotten. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sachin P. Sant <sachinp@in.ibm.com>
Impact: code reorganization
Separate out embedding first chunk setup helper from x86 embedding
first chunk allocator and put it in mm/percpu.c. This will be used by
the default percpu first chunk allocator and possibly by other archs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleanup, more flexibility for first chunk init
Non-negative @dyn_size used to be allowed iff @unit_size wasn't auto.
This restriction stemmed from implementation detail and made things a
bit less intuitive. This patch allows @dyn_size to be specified
regardless of @unit_size and swaps the positions of @dyn_size and
@unit_size so that the parameter order makes more sense (static,
reserved and dyn sizes followed by enclosing unit_size).
While at it, add @unit_size >= PCPU_MIN_UNIT_SIZE sanity check.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: generic addr <-> pcpu ptr conversion macros
There's nothing arch specific about x86 __addr_to_pcpu_ptr() and
__pcpu_ptr_to_addr(). With proper __per_cpu_load and __per_cpu_start
defined, they'll do the right thing regardless of actual layout.
Move these macros from arch/x86/include/asm/percpu.h to mm/percpu.c
and allow archs to override it as necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: fix deadlock and allow atomic free
Percpu allocation always uses GFP_KERNEL and whole alloc/free paths
were protected by single mutex. All percpu allocations have been from
GFP_KERNEL-safe context and the original allocator had this assumption
too. However, by protecting both alloc and free paths with the same
mutex, the new allocator creates free -> alloc -> GFP_KERNEL
dependency which the original allocator didn't have. This can lead to
deadlock if free is called from FS or IO paths. Also, in general,
allocators are expected to allow free to be called from atomic
context.
This patch implements finer grained locking to break the deadlock and
allow atomic free. For details, please read the "Synchronization
rules" comment.
While at it, also add CONTEXT: to function comments to describe which
context they expect to be called from and what they do to it.
This problem was reported by Thomas Gleixner and Peter Zijlstra.
http://thread.gmane.org/gmane.linux.kernel/802384
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Peter Zijlstra <peterz@infradead.org>
This is an architecture independant synchronization around kernel text
modifications through use of a global mutex.
A mutex has been chosen so that kprobes, the main user of this, can sleep
during memory allocation between the memory read of the instructions it
must replace and the memory write of the breakpoint.
Other user of this interface: immediate values.
Paravirt and alternatives are always done when SMP is inactive, so there
is no need to use locks.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <49B142D8.7020601@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: code reorganization for later changes
Do fully free chunk reclamation using a work. This change is to
prepare for locking changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: code reorganization for later changes
Separate out chunk area map extension into a separate function -
pcpu_extend_area_map() - and call it directly from pcpu_alloc() such
that pcpu_alloc_area() is guaranteed to have enough area map slots on
invocation.
With this change, pcpu_alloc_area() does only area allocation and the
only failure mode is when the chunk doens't have enough room, so
there's no need to distinguish it from memory allocation failures.
Make it return -1 on such cases instead of hacky -ENOSPC.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: code reorganization for later changes
With static map handling moved to pcpu_split_block(), pcpu_realloc()
only clutters the code and it's also unsuitable for scheduled locking
changes. Implement and use pcpu_mem_alloc/free() instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: add reserved allocation functionality and use it for module
percpu variables
This patch implements reserved allocation from the first chunk. When
setting up the first chunk, arch can ask to set aside certain number
of bytes right after the core static area which is available only
through a separate reserved allocator. This will be used primarily
for module static percpu variables on architectures with limited
relocation range to ensure that the module perpcu symbols are inside
the relocatable range.
If reserved area is requested, the first chunk becomes reserved and
isn't available for regular allocation. If the first chunk also
includes piggy-back dynamic allocation area, a separate chunk mapping
the same region is created to serve dynamic allocation. The first one
is called static first chunk and the second dynamic first chunk.
Although they share the page map, their different area map
initializations guarantee they serve disjoint areas according to their
purposes.
If arch doesn't setup reserved area, reserved allocation is handled
like any other allocation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: allow sharing page map, no functional difference yet
Make chunk->page access indirect by adding a pointer and renaming the
actual array to page_ar. This will be used by future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: argument semantic cleanup
In pcpu_setup_first_chunk(), zero @unit_size and @dyn_size meant
auto-sizing. It's okay for @unit_size as 0 doesn't make sense but 0
dynamic reserve size is valid. Alos, if arch @dyn_size is calculated
from other parameters, it might end up passing in 0 @dyn_size and
malfunction when the size is automatically adjusted.
This patch makes both @unit_size and @dyn_size ssize_t and use -1 for
auto sizing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: no functional change
When the first chunk is created, its initial area map is not allocated
because kmalloc isn't online yet. The map is allocated and
initialized on the first allocation request on the chunk. This works
fine but the scattering of initialization logic between the init
function and allocation path is a bit confusing.
This patch makes the first chunk initialize and use minimal statically
allocated map from pcpu_setpu_first_chunk(). The map resizing path
still needs to handle this specially but it's more straight-forward
and gives more latitude to the init path. This will ease future
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cosmetic, preparation for future changes
Make the following renames in pcpur_setup_first_chunk() in preparation
for future changes.
* s/free_size/dyn_size/
* s/static_vm/first_vm/
* s/static_chunk/schunk/
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: standardize IO on cached ops
On modern CPUs it is almost always a bad idea to use non-temporal stores,
as the regression in this commit has shown it:
30d697f: x86: fix performance regression in write() syscall
The kernel simply has no good information about whether using non-temporal
stores is a good idea or not - and trying to add heuristics only increases
complexity and inserts fragility.
The regression on cached write()s took very long to be found - over two
years. So dont take any chances and let the hardware decide how it makes
use of its caches.
The only exception is drivers/gpu/drm/i915/i915_gem.c: there were we are
absolutely sure that another entity (the GPU) will pick up the dirty
data immediately and that the CPU will not touch that data before the
GPU will.
Also, keep the _nocache() primitives to make it easier for people to
experiment with these details. There may be more clear-cut cases where
non-cached copies can be used, outside of filemap.c.
Cc: Salman Qazi <sqazi@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix new breakages introduced by previous fix
Commit c132937556 tried to clean up
bootmem arch wrapper but it wasn't quite correct. Before the commit,
the followings were broken.
* Low level interface functions prefixed with __ ignored arch
preference.
* reserve_bootmem(...) can't be mapped into
reserve_bootmem_node(NODE_DATA(0)->bdata, ...) because the node is
not preference here. The region specified MUST fall into the
specified region; otherwise, it will panic.
After the commit,
* If allocation fails for the arch preferred node, it should fallback
to whatever is available. Instead, it simply failed allocation.
There are too many internal details to allow generic wrapping and
still keep things simple for archs. Plus, all that arch wants is a
way to prefer certain node over another.
This patch drops the generic wrapping around alloc_bootmem_core() and
add alloc_bootmem_core() instead. If necessary, arch can define
bootmem_arch_referred_node() macro or function which takes all
allocation information and returns the preferred node. bootmem
generic code will always try the preferred node first and then
fallback to other nodes as usual.
Breakages noted and changes reviewed by Johannes Weiner.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Impact: remove compile warning
Mark local variable map_end in pcpu_populate_chunk() with
uninitialized_var(). The variable is always used in tandem with
map_start and guaranteed to be initialized before use but gcc doesn't
understand that.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
I just got this new warning from kmemcheck:
WARNING: kmemcheck: Caught 32-bit read from freed memory (c7806a60)
a06a80c7ecde70c1a04080c700000000a06709c1000000000000000000000000
f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f
^
Pid: 0, comm: swapper Not tainted (2.6.29-rc4 #230)
EIP: 0060:[<c1096df7>] EFLAGS: 00000286 CPU: 0
EIP is at __purge_vmap_area_lazy+0x117/0x140
EAX: 00070f43 EBX: c7806a40 ECX: c1677080 EDX: 00027b66
ESI: 00002001 EDI: c170df0c EBP: c170df00 ESP: c178830c
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
CR0: 80050033 CR2: c7806b14 CR3: 01775000 CR4: 00000690
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: 00004000 DR7: 00000000
[<c1096f3e>] free_unmap_vmap_area_noflush+0x6e/0x70
[<c1096f6a>] remove_vm_area+0x2a/0x70
[<c1097025>] __vunmap+0x45/0xe0
[<c10970de>] vunmap+0x1e/0x30
[<c1008ba5>] text_poke+0x95/0x150
[<c1008ca9>] alternatives_smp_unlock+0x49/0x60
[<c171ef47>] alternative_instructions+0x11b/0x124
[<c171f991>] check_bugs+0xbd/0xdc
[<c17148c5>] start_kernel+0x2ed/0x360
[<c171409e>] __init_begin+0x9e/0xa9
[<ffffffff>] 0xffffffff
It happened here:
$ addr2line -e vmlinux -i c1096df7
mm/vmalloc.c:540
Code:
list_for_each_entry(va, &valist, purge_list)
__free_vmap_area(va);
It's this instruction:
mov 0x20(%ebx),%edx
Which corresponds to a dereference of va->purge_list.next:
(gdb) p ((struct vmap_area *) 0)->purge_list.next
Cannot access memory at address 0x20
It seems that we should use "safe" list traversal here, as the element
is freed inside the loop. Please verify that this is the right fix.
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The new vmap allocator can wrap the address and get confused in the case
of large allocations or VMALLOC_END near the end of address space.
Problem reported by Christoph Hellwig on a 32-bit XFS workload.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reported-by: Christoph Hellwig <hch@lst.de>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Each time I exit Firefox, /proc/meminfo's Committed_AS goes down almost
400 kB: OVERCOMMIT_NEVER would be allowing overcommits it should
prohibit.
Commit fc8744adc8 "Stop playing silly
games with the VM_ACCOUNT flag" changed shmem_file_setup() to set the
shmem file's VM_ACCOUNT flag according to VM_NORESERVE not being set in
the vma flags; but did so only _after_ the shmem_acct_size(flags, size)
call which is expected to pre-account a shared anonymous object.
It's all clearer if we switch shmem.c over to use VM_NORESERVE
throughout in place of !VM_ACCOUNT.
But I very nearly sent in a patch which mistakenly removed the
accounting from tmpfs files: shmem_get_inode()'s memset was good for not
setting VM_ACCOUNT, but now it needs to set VM_NORESERVE.
Rather than setting that by default, then perhaps clearing it again in
shmem_file_setup(), let's pass it as a flag to shmem_get_inode(): that
allows us to remove the #ifdef CONFIG_SHMEM from shmem_file_setup().
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: cleanup, enable future change
Add a 'total bytes copied' parameter to __copy_from_user_*nocache(),
and update all the callsites.
The parameter is not used yet - architecture code can use it to
more intelligently decide whether the copy should be cached or
non-temporal.
Cc: Salman Qazi <sqazi@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As suggested by Christoph Lameter, rename calculate_min_partial() to
set_min_partial() as the function doesn't really do any calculations.
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Most global variables in percpu allocator are initialized during boot
and read only from that point on. Add __read_mostly as per Rusty's
suggestion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Impact: more latitude for first percpu chunk allocation
The first percpu chunk serves the kernel static percpu area and may or
may not contain extra room for further dynamic allocation.
Initialization of the first chunk needs to be done before normal
memory allocation service is up, so it has its own init path -
pcpu_setup_static().
It seems archs need more latitude while initializing the first chunk
for example to take advantage of large page mapping. This patch makes
the following changes to allow this.
* Define PERCPU_DYNAMIC_RESERVE to give arch hint about how much space
to reserve in the first chunk for further dynamic allocation.
* Rename pcpu_setup_static() to pcpu_setup_first_chunk().
* Make pcpu_setup_first_chunk() much more flexible by fetching page
pointer by callback and adding optional @unit_size, @free_size and
@base_addr arguments which allow archs to selectively part of chunk
initialization to their likings.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: allow unit_size to be arbitrary multiple of PAGE_SIZE
In dynamic percpu allocator, there is no reason the unit size should
be power of two. Remove the restriction.
As non-power-of-two unit size means that empty chunks fall into the
same slot index as lightly occupied chunks which is bad for reclaming.
Reserve an extra slot for empty chunks.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: allow larger alignment for early vmalloc area allocation
Some early vmalloc users might want larger alignment, for example, for
custom large page mapping. Add @align to vm_area_register_early().
While at it, drop docbook comment on non-existent @size.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Impact: cleaner and consistent bootmem wrapping
By setting CONFIG_HAVE_ARCH_BOOTMEM_NODE, archs can define
arch-specific wrappers for bootmem allocation. However, this is done
a bit strangely in that only the high level convenience macros can be
changed while lower level, but still exported, interface functions
can't be wrapped. This not only is messy but also leads to strange
situation where alloc_bootmem() does what the arch wants it to do but
the equivalent __alloc_bootmem() call doesn't although they should be
able to be used interchangeably.
This patch updates bootmem such that archs can override / wrap the
backend function - alloc_bootmem_core() instead of the highlevel
interface functions to allow simpler and consistent wrapping. Also,
HAVE_ARCH_BOOTMEM_NODE is renamed to HAVE_ARCH_BOOTMEM.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@saeurebad.de>
Impact: fix short allocation leading to memory corruption
While dropping rvalue wrapping macros around global parameters,
pcpu_chunk_struct_size was set incorrectly resulting in shorter page
pointer array. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that a cache's min_partial has been moved to struct kmem_cache, it's
possible to easily tune it from userspace by adding a sysfs attribute.
It may not be desirable to keep a large number of partial slabs around
if a cache is used infrequently and memory, especially when constrained
by a cgroup, is scarce. It's better to allow userspace to set the
minimum policy per cache instead of relying explicitly on
kmem_cache_shrink().
The memory savings from simply moving min_partial from struct
kmem_cache_node to struct kmem_cache is obviously not significant
(unless maybe you're from SGI or something), at the largest it's
# allocated caches * (MAX_NUMNODES - 1) * sizeof(unsigned long)
The true savings occurs when userspace reduces the number of partial
slabs that would otherwise be wasted, especially on machines with a
large number of nodes (ia64 with CONFIG_NODES_SHIFT at 10 for default?).
As well as the kernel estimates ideal values for n->min_partial and
ensures it's within a sane range, userspace has no other input other
than writing to /sys/kernel/slab/cache/shrink.
There simply isn't any better heuristic to add when calculating the
partial values for a better estimate that works for all possible caches.
And since it's currently a static value, the user really has no way of
reclaiming that wasted space, which can be significant when constrained
by a cgroup (either cpusets or, later, memory controller slab limits)
without shrinking it entirely.
This also allows the user to specify that increased fragmentation and
more partial slabs are actually desired to avoid the cost of allocating
new slabs at runtime for specific caches.
There's also no reason why this should be a per-struct kmem_cache_node
value in the first place. You could argue that a machine would have
such node size asymmetries that it should be specified on a per-node
basis, but we know nobody is doing that right now since it's a purely
static value at the moment and there's no convenient way to tune that
via slub's sysfs interface.
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Although it allows for better cacheline use, it is unnecessary to save a
copy of the cache's min_partial value in each kmem_cache_node.
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* hibernate:
PM: Fix suspend_console and resume_console to use only one semaphore
PM: Wait for console in resume
PM: Fix pm_notifiers during user mode hibernation
swsusp: clean up shrink_all_zones()
swsusp: dont fiddle with swappiness
PM: fix build for CONFIG_PM unset
PM/hibernate: fix "swap breaks after hibernation failures"
PM/resume: wait for device probing to finish
Consolidate driver_probe_done() loops into one place
Move local variables to innermost possible scopes and use local
variables to cache calculations/reads done more than once.
No change in functionality (intended).
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sc.swappiness is not used in the swsusp memory shrinking path, do not
set it.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
http://bugzilla.kernel.org/show_bug.cgi?id=12239
The image writing code dropped a reference to the current swap device.
This doesn't show up if the hibernation succeeds - because it doesn't
affect the image which gets resumed. But it means multiple _failed_
hibernations end up freeing the swap device while it is still use!
swsusp_write() finds the block device for the swap file using swap_type_of().
It then uses blkdev_get() / blkdev_put() to open and close the block device.
Unfortunately, blkdev_get() assumes ownership of the inode of the block_device
passed to it. So blkdev_put() calls iput() on the inode. This is by design
and other callers expect this behaviour. The fix is for swap_type_of() to take
a reference on the inode using bdget().
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew was concerned about the unit of variables named or have suffix
size. Every usage in percpu allocator is in bytes but make it super
clear by adding comments.
While at it, make pcpu_depopulate_chunk() take int @off and @size like
everyone else.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Impact: proper vcache flush on unmap_kernel_range()
flush_cache_vunmap() should be called before pages are unmapped. Add
a call to it in unmap_kernel_range().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Nick Piggin <npiggin@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kzfree() is a wrapper for kfree() that additionally zeroes the underlying
memory before releasing it to the slab allocator.
Currently there is code which memset()s the memory region of an object
before releasing it back to the slab allocator to make sure
security-sensitive data are really zeroed out after use.
These callsites can then just use kzfree() which saves some code, makes
users greppable and allows for a stupid destructor that isn't necessarily
aware of the actual object size.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
