The comment is useless after commit 57a196a584 ("hugetlb: simplify
hugetlb handling in follow_page_mask") since all follow_huge_foo() are
killed.
Link: https://lkml.kernel.org/r/20240725021643.1358536-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kmemleak: support for percpu memory leak detect'.
This is a rework of this series:
https://lore.kernel.org/lkml/20200921020007.35803-1-chenjun102@huawei.com/
Originally I was investigating a percpu leak on our customer nodes and
having this functionality was a huge help, which lead to this fix [1].
So probably it's a good idea to have it in mainstream too, especially as
after [2] it became much easier to implement (we already have a separate
tree for percpu pointers).
[1] commit 0af8c09c89 ("netfilter: x_tables: fix percpu counter block leak on error path when creating new netns")
[2] commit 39042079a0 ("kmemleak: avoid RCU stalls when freeing metadata for per-CPU pointers")
This patch (of 2):
This basically does:
- Add min_percpu_addr and max_percpu_addr to filter out unrelated data
similar to min_addr and max_addr;
- Set min_count for percpu pointers to 1 to start tracking them;
- Calculate checksum of percpu area as xor of crc32 for each cpu;
- Split pointer lookup and update refs code into separate helper and use
it twice: once as if the pointer is a virtual pointer and once as if
it's percpu.
[ptikhomirov@virtuozzo.com: v2]
Link: https://lkml.kernel.org/r/20240731025526.157529-2-ptikhomirov@virtuozzo.com
Link: https://lkml.kernel.org/r/20240725041223.872472-1-ptikhomirov@virtuozzo.com
Link: https://lkml.kernel.org/r/20240725041223.872472-2-ptikhomirov@virtuozzo.com
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Chen Jun <chenjun102@huawei.com>
Cc: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As part of the dynamic kernel stack project, we need to know the amount of
data that can be saved by reducing the default kernel stack size [1].
Provide a kernel stack usage histogram to aid in optimizing kernel stack
sizes and minimizing memory waste in large-scale environments. The
histogram divides stack usage into power-of-two buckets and reports the
results in /proc/vmstat. This information is especially valuable in
environments with millions of machines, where even small optimizations can
have a significant impact.
The histogram data is presented in /proc/vmstat with entries like
"kstack_1k", "kstack_2k", and so on, indicating the number of threads that
exited with stack usage falling within each respective bucket.
Example outputs:
Intel:
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
ARM with 64K page_size:
$ grep kstack /proc/vmstat
kstack_1k 1
kstack_2k 340
kstack_4k 25212
kstack_8k 1659
kstack_16k 0
kstack_32k 0
kstack_64k 0
Note: once the dynamic kernel stack is implemented it will depend on the
implementation the usability of this feature: On hardware that supports
faults on kernel stacks, we will have other metrics that show the total
number of pages allocated for stacks. On hardware where faults are not
supported, we will most likely have some optimization where only some
threads are extended, and for those, these metrics will still be very
useful.
[1] https://lwn.net/Articles/974367
Link: https://lkml.kernel.org/r/20240730150158.832783-3-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-3-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Kernel stack usage histogram", v6.
Provide histogram of stack sizes for the exited threads:
Example outputs:
Intel:
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
ARM with 64K page_size:
$ grep kstack /proc/vmstat
kstack_1k 1
kstack_2k 340
kstack_4k 25212
kstack_8k 1659
kstack_16k 0
kstack_32k 0
kstack_64k 0
This patch (of 3):
At the moment the valid index for the indirection tables for memcg stats
and events is < S8_MAX. These indirection tables are used in performance
critical codepaths. With the latest addition to the vm_events, the
NR_VM_EVENT_ITEMS has gone over S8_MAX. One way to resolve is to increase
the entry size of the indirection table from int8_t to int16_t but this
will increase the potential number of cachelines needed to access the
indirection table.
This patch took a different approach and make the valid index < U8_MAX.
In this way the size of the indirection tables will remain same and we
only need to invalid index check from less than 0 to equal to U8_MAX. In
this approach we have also removed a subtraction from the performance
critical codepaths.
[pasha.tatashin@soleen.com: v6]
Link: https://lkml.kernel.org/r/20240730150158.832783-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-2-pasha.tatashin@soleen.com
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Co-developed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The releasing process of the non-shared anonymous folio mapped solely by
an exiting process may go through two flows: 1) the anonymous folio is
firstly is swaped-out into swapspace and transformed into a swp_entry in
shrink_folio_list; 2) then the swp_entry is released in the process
exiting flow. This will result in the high cpu load of releasing a
non-shared anonymous folio mapped solely by an exiting process.
When the low system memory and the exiting process exist at the same time,
it will be likely to happen, because the non-shared anonymous folio mapped
solely by an exiting process may be reclaimed by shrink_folio_list.
This patch is that shrink skips the non-shared anonymous folio solely
mapped by an exting process and this folio is only released directly in
the process exiting flow, which will save swap-out time and alleviate the
load of the process exiting.
Barry provided some effectiveness testing in [1]. "I observed that
this patch effectively skipped 6114 folios (either 4KB or 64KB mTHP),
potentially reducing the swap-out by up to 92MB (97,300,480 bytes)
during the process exit. The working set size is 256MB."
Link: https://lkml.kernel.org/r/20240710083641.546-1-justinjiang@vivo.com
Link: https://lore.kernel.org/linux-mm/20240710033212.36497-1-21cnbao@gmail.com/ [1]
Signed-off-by: Zhiguo Jiang <justinjiang@vivo.com>
Acked-by: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fold lru_rotate into cpu_fbatches, and rename the folio_batch and the lock
protecting it to lru_move_tail and lock_irq respectively so that all the
boilerplate can be removed at the end of this series.
Also remove data_race() around folio_batch_count(), which is out of place:
all folio_batch_count() calls on remote cpu_fbatches are subject to
data_race(), and therefore data_race() should be inside
folio_batch_count().
Link: https://lkml.kernel.org/r/20240711021317.596178-4-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename cpu_fbatches->activate to cpu_fbatches->lru_activate, and its
handler folio_activate_fn() to lru_activate() so that all the boilerplate
can be removed at the end of this series.
Link: https://lkml.kernel.org/r/20240711021317.596178-3-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/swap: remove boilerplate".
This patch (of 5):
Use folio_activate() as an example:
Before this series
------------------
if (!folio_test_active(folio) && !folio_test_unevictable(folio)) {
struct folio_batch *fbatch;
folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}
local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.activate);
folio_batch_add_and_move(fbatch, folio, folio_activate_fn);
local_unlock(&cpu_fbatches.lock);
}
}
After this series
-----------------
void folio_activate(struct folio *folio)
{
if (folio_test_active(folio) || folio_test_unevictable(folio))
return;
folio_batch_add_and_move(folio, lru_activate, true);
}
And this is applied to all 6 folio_batch handlers in mm/swap.c.
bloat-o-meter
-------------
add/remove: 12/13 grow/shrink: 3/2 up/down: 4653/-4721 (-68)
...
Total: Before=28083019, After=28082951, chg -0.00%
This patch (of 5):
Reduce indentation level by returning directly when there is no cleanup
needed, i.e.,
if (condition) { | if (condition) {
do_this(); | do_this();
return; | return;
} else { | }
do_that(); |
} | do_that();
and
if (condition) { | if (!condition)
do_this(); | return;
do_that(); |
} | do_this();
return; | do_that();
Presumably the old style became repetitive as the result of copy and
paste.
Link: https://lkml.kernel.org/r/20240711021317.596178-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/20240711021317.596178-2-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
memory tiering can be enabled/disabled at runtime and
sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING is used to
check it. In migrate_misplaced_folio(), the check is missing when
PGPROMOTE_SUCCESS is incremented. Add the missing check.
Link: https://lkml.kernel.org/r/20240724130115.793641-4-ziy@nvidia.com
Fixes: 33024536ba ("memory tiering: hot page selection with hint page fault latency")
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Closes: https://lore.kernel.org/linux-mm/f4ae2c9c-fe40-4807-bdb2-64cf2d716c1a@huawei.com/
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If memory tiering mode is on and a folio is not in the top tier memory,
folio's cpupid field is repurposed to store page access time. Instead of
an open coded check, use a function to encapsulate the check.
Link: https://lkml.kernel.org/r/20240724130115.793641-3-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Various memory tiering fixes", v3.
This patch (of 3):
last_cpupid is only available when memory tiering is off or the folio is
in toptier node. Complete the check to read last_cpupid when it is
available.
Before the fix, the default last_cpupid will be used even if memory
tiering mode is turned off at runtime instead of the actual value. This
can prevent task_numa_fault() from getting right numa fault stats, but
should not cause any crash. User might see performance changes after the
fix.
Link: https://lkml.kernel.org/r/20240724130115.793641-1-ziy@nvidia.com
Link: https://lkml.kernel.org/r/20240724130115.793641-2-ziy@nvidia.com
Fixes: 33024536ba ("memory tiering: hot page selection with hint page fault latency")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: David Hildenbrand <david@redhat.com>
Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@redhat.com/
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Extend a usage parameter so that cluster_swap_free_nr() can be reused by
both swapcache_clear() and swap_free(). __swap_entry_free() is quite
similar but more tricky as it requires the return value of
__swap_entry_free_locked() which cluster_swap_free_nr() doesn't support.
Link: https://lkml.kernel.org/r/20240724020056.65838-1-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is no user of mem_cgroup_from_obj(), remove it.
Link: https://lkml.kernel.org/r/20240718091821.44740-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now that we're not passing around a pointer to the flags, there's no
reason to have an extra variable for the gup_flags, simply pass the
gup_flags directly everywhere.
Link: https://lkml.kernel.org/r/1e79b84bd30287cc9847f2aeb002374e6e60a10f.1721337845.git.josef@toxicpanda.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: some small page fault cleanups".
I was recently wreaking havoc in the page fault code and I noticed some
things that could be cleaned up. We no longer modify the gup flags in
faultin_page, so we can clean up how we pass the flags in and remove the
extra variable in __get_user_pages.
This patch (of 2):
We're passing a pointer to the foll_flags for faultin_page, however we
never modify the flags in this call. Change this to just take the flags
value instead.
Link: https://lkml.kernel.org/r/2df51a54c06bdf93e1cb09a19a9ef1df6557b59e.1721337845.git.josef@toxicpanda.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When KASAN is enabled and built with clang:
mm/damon/lru_sort.c:199:12: error: stack frame size (2328) exceeds
limit (2048) in 'damon_lru_sort_apply_parameters' [-Werror,-Wframe-larger-than]
static int damon_lru_sort_apply_parameters(void)
^
1 error generated.
This is because damon_lru_sort_quota contains a large array, and
assigning this variable to a local variable causes a large amount of
stack space to be occupied.
So adjust local variable to dynamic allocation.
Link: https://lkml.kernel.org/r/20240723035513.20153-1-flyingpeng@tencent.com
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
hugetlb_vmemmap_optimize_folio() and hugetlb_vmemmap_restore_folio() are
wrappers meant to be called regardless of whether HVO is enabled.
Therefore, they should not call synchronize_rcu(). Otherwise, it
regresses use cases not enabling HVO.
So move synchronize_rcu() to __hugetlb_vmemmap_optimize_folio() and
__hugetlb_vmemmap_restore_folio(), and call it once for each batch of
folios when HVO is enabled.
Link: https://lkml.kernel.org/r/20240719042503.2752316-1-yuzhao@google.com
Fixes: bd225530a4 ("mm/hugetlb_vmemmap: fix race with speculative PFN walkers")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202407091001.1250ad4a-oliver.sang@intel.com
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Acked-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Initially I added shmem-quota to obj-y, move it to the correct place and
remove the unneeded full file #ifdef
Link: https://lkml.kernel.org/r/20240717063737.910840-1-cem@kernel.org
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Suggested-by: Aristeu Rozanski <aris@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move shmem_huge_global_enabled() into shmem_allowable_huge_orders(), so
that shmem_allowable_huge_orders() can also help to find the allowable
huge orders for tmpfs. Moreover the shmem_huge_global_enabled() can
become static. While we are at it, passing the vma instead of mm for
shmem_huge_global_enabled() makes code cleaner.
No functional changes.
Link: https://lkml.kernel.org/r/8e825146bb29ee1a1c7bd64d2968ff3e19be7815.1721626645.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
shmem_is_huge() is now used to check if the top-level huge page is
enabled, thus rename it to reflect its usage.
Link: https://lkml.kernel.org/r/da53296e0ab6359aa083561d9dc01e4223d60fbe.1721626645.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Some cleanups for shmem", v3.
This series does some cleanups to reuse code, rename functions and
simplify logic to make code more clear. No functional changes are
expected.
This patch (of 3):
Move the suitable huge orders validation into shmem_suitable_orders() for
tmpfs, which can reuse some code to simplify the logic.
In addition, we don't have special handling for the error code -E2BIG when
checking for conflicts with PMD sized THP in the pagecache for tmpfs,
instead, it will just fallback to order-0 allocations like this patch
does, so this simplification will not add functional changes.
Link: https://lkml.kernel.org/r/cover.1721626645.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/965985dd6d322929d78a0beee0dafa1c2a1b81e2.1721626645.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:
- krealloc() frees the memory when the requested size is zero, whereas
kvrealloc() simply returns a pointer to the existing allocation.
- krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
kvrealloc() does not accept a NULL pointer at all and, if passed,
would fault instead.
- krealloc() is self-contained, whereas kvrealloc() relies on the caller
to provide the size of the previous allocation.
Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.
Besides that, implementing kvrealloc() by making use of krealloc() and
vrealloc() provides oppertunities to grow (and shrink) allocations more
efficiently. For instance, vrealloc() can be optimized to allocate and
map additional pages to grow the allocation or unmap and free unused pages
to shrink the allocation.
[dakr@kernel.org: document concurrency restrictions]
Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@kernel.org
[dakr@kernel.org: disable KASAN when switching to vmalloc]
Link: https://lkml.kernel.org/r/20240730185049.6244-2-dakr@kernel.org
[dakr@kernel.org: properly document __GFP_ZERO behavior]
Link: https://lkml.kernel.org/r/20240730185049.6244-5-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Align kvrealloc() with krealloc()", v2.
Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:
- krealloc() frees the memory when the requested size is zero, whereas
kvrealloc() simply returns a pointer to the existing allocation.
- krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
kvrealloc() does not accept a NULL pointer at all and, if passed, would fault
instead.
- krealloc() is self-contained, whereas kvrealloc() relies on the caller to
provide the size of the previous allocation.
Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.
In order to be able to get rid of kvrealloc()'s oldsize parameter,
introduce vrealloc() and make use of it in kvrealloc().
Making use of vrealloc() in kvrealloc() also provides oppertunities to
grow (and shrink) allocations more efficiently. For instance, vrealloc()
can be optimized to allocate and map additional pages to grow the
allocation or unmap and free unused pages to shrink the allocation.
Besides the above, those functions are required by Rust's allocator abstractons
[1] (rework based on this series in [2]). With `Vec` or `KVec` respectively,
potentially growing (and shrinking) data structures are rather common.
[1] https://lore.kernel.org/lkml/20240704170738.3621-1-dakr@redhat.com/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/mm
This patch (of 2):
Implement vrealloc() analogous to krealloc().
Currently, krealloc() requires the caller to pass the size of the previous
memory allocation, which, instead, should be self-contained.
We attempt to fix this in a subsequent patch which, in order to do so,
requires vrealloc().
Besides that, we need realloc() functions for kernel allocators in Rust
too. With `Vec` or `KVec` respectively, potentially growing (and
shrinking) data structures are rather common.
[dakr@kernel.org: fix missing nommu implementation]
Link: https://lkml.kernel.org/r/20240725141227.13954-1-dakr@kernel.org
[dakr@kernel.org: document concurrency restrictions]
Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@kernel.org
[dakr@kernel.org: consider spare memory for __GFP_ZERO]
Link: https://lkml.kernel.org/r/20240730185049.6244-3-dakr@kernel.org
[dakr@kernel.org: properly document __GFP_ZERO behavior]
Link: https://lkml.kernel.org/r/20240730185049.6244-4-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-1-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
/proc/vmstat currently shows the number of node_reclaim() failures when
vm.zone_reclaim_mode is set appropriately. It would be convenient to have
the number of successes right next to zone_reclaim_failed (similar to
compaction and migration).
While just a trivially addition to the vmstat file. It was helpful during
benchmarking to not have to probe node_reclaim() to observe the
success/failure ratio.
Link: https://lkml.kernel.org/r/20240722171316.7517-1-mcassell411@gmail.com
Signed-off-by: Matthew Cassell <mcassell411@gmail.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When AS_RELEASE_ALWAYS is set on a mapping, the ->release_folio() and
->invalidate_folio() calls should be invoked even if PG_private and
PG_private_2 aren't set. This is used by netfslib to keep track of the
point above which reads can be skipped in favour of just zeroing pagecache
locally.
There are a couple of places in truncation in which invalidation is only
called when folio_has_private() is true. Fix these to check
folio_needs_release() instead.
Without this, the generic/075 and generic/112 xfstests (both fsx-based
tests) fail with minimum folio size patches applied[1].
Fixes: b4fa966f03 ("mm, netfs, fscache: stop read optimisation when folio removed from pagecache")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240815090849.972355-1-kernel@pankajraghav.com/ [1]
Link: https://lore.kernel.org/r/20240823200819.532106-2-dhowells@redhat.com
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Pankaj Raghav <p.raghav@samsung.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
the others pertain to post-6.10 issues.
As usual with these merges, singletons and doubletons all over the place,
no identifiable-by-me theme. Please see the lovingly curated changelogs
to get the skinny.
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Merge tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"16 hotfixes. All except one are for MM. 10 of these are cc:stable and
the others pertain to post-6.10 issues.
As usual with these merges, singletons and doubletons all over the
place, no identifiable-by-me theme. Please see the lovingly curated
changelogs to get the skinny"
* tag 'mm-hotfixes-stable-2024-08-17-19-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/migrate: fix deadlock in migrate_pages_batch() on large folios
alloc_tag: mark pages reserved during CMA activation as not tagged
alloc_tag: introduce clear_page_tag_ref() helper function
crash: fix riscv64 crash memory reserve dead loop
selftests: memfd_secret: don't build memfd_secret test on unsupported arches
mm: fix endless reclaim on machines with unaccepted memory
selftests/mm: compaction_test: fix off by one in check_compaction()
mm/numa: no task_numa_fault() call if PMD is changed
mm/numa: no task_numa_fault() call if PTE is changed
mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu
mm: don't account memmap per-node
mm: add system wide stats items category
mm: don't account memmap on failure
mm/hugetlb: fix hugetlb vs. core-mm PT locking
mseal: fix is_madv_discard()
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Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull memcg-v1 fix from Al Viro:
"memcg_write_event_control() oops fix"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
memcg_write_event_control(): fix a user-triggerable oops
Currently, migrate_pages_batch() can lock multiple locked folios with an
arbitrary order. Although folio_trylock() is used to avoid deadlock as
commit 2ef7dbb269 ("migrate_pages: try migrate in batch asynchronously
firstly") mentioned, it seems try_split_folio() is still missing.
It was found by compaction stress test when I explicitly enable EROFS
compressed files to use large folios, which case I cannot reproduce with
the same workload if large folio support is off (current mainline).
Typically, filesystem reads (with locked file-backed folios) could use
another bdev/meta inode to load some other I/Os (e.g. inode extent
metadata or caching compressed data), so the locking order will be:
file-backed folios (A)
bdev/meta folios (B)
The following calltrace shows the deadlock:
Thread 1 takes (B) lock and tries to take folio (A) lock
Thread 2 takes (A) lock and tries to take folio (B) lock
[Thread 1]
INFO: task stress:1824 blocked for more than 30 seconds.
Tainted: G OE 6.10.0-rc7+ #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:stress state:D stack:0 pid:1824 tgid:1824 ppid:1822 flags:0x0000000c
Call trace:
__switch_to+0xec/0x138
__schedule+0x43c/0xcb0
schedule+0x54/0x198
io_schedule+0x44/0x70
folio_wait_bit_common+0x184/0x3f8
<-- folio mapping ffff00036d69cb18 index 996 (**)
__folio_lock+0x24/0x38
migrate_pages_batch+0x77c/0xea0 // try_split_folio (mm/migrate.c:1486:2)
// migrate_pages_batch (mm/migrate.c:1734:16)
<--- LIST_HEAD(unmap_folios) has
..
folio mapping 0xffff0000d184f1d8 index 1711; (*)
folio mapping 0xffff0000d184f1d8 index 1712;
..
migrate_pages+0xb28/0xe90
compact_zone+0xa08/0x10f0
compact_node+0x9c/0x180
sysctl_compaction_handler+0x8c/0x118
proc_sys_call_handler+0x1a8/0x280
proc_sys_write+0x1c/0x30
vfs_write+0x240/0x380
ksys_write+0x78/0x118
__arm64_sys_write+0x24/0x38
invoke_syscall+0x78/0x108
el0_svc_common.constprop.0+0x48/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x3c/0x148
el0t_64_sync_handler+0x100/0x130
el0t_64_sync+0x190/0x198
[Thread 2]
INFO: task stress:1825 blocked for more than 30 seconds.
Tainted: G OE 6.10.0-rc7+ #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:stress state:D stack:0 pid:1825 tgid:1825 ppid:1822 flags:0x0000000c
Call trace:
__switch_to+0xec/0x138
__schedule+0x43c/0xcb0
schedule+0x54/0x198
io_schedule+0x44/0x70
folio_wait_bit_common+0x184/0x3f8
<-- folio = 0xfffffdffc6b503c0 (mapping == 0xffff0000d184f1d8 index == 1711) (*)
__folio_lock+0x24/0x38
z_erofs_runqueue+0x384/0x9c0 [erofs]
z_erofs_readahead+0x21c/0x350 [erofs] <-- folio mapping 0xffff00036d69cb18 range from [992, 1024] (**)
read_pages+0x74/0x328
page_cache_ra_order+0x26c/0x348
ondemand_readahead+0x1c0/0x3a0
page_cache_sync_ra+0x9c/0xc0
filemap_get_pages+0xc4/0x708
filemap_read+0x104/0x3a8
generic_file_read_iter+0x4c/0x150
vfs_read+0x27c/0x330
ksys_pread64+0x84/0xd0
__arm64_sys_pread64+0x28/0x40
invoke_syscall+0x78/0x108
el0_svc_common.constprop.0+0x48/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x3c/0x148
el0t_64_sync_handler+0x100/0x130
el0t_64_sync+0x190/0x198
Link: https://lkml.kernel.org/r/20240729021306.398286-1-hsiangkao@linux.alibaba.com
Fixes: 5dfab109d5 ("migrate_pages: batch _unmap and _move")
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
During CMA activation, pages in CMA area are prepared and then freed
without being allocated. This triggers warnings when memory allocation
debug config (CONFIG_MEM_ALLOC_PROFILING_DEBUG) is enabled. Fix this by
marking these pages not tagged before freeing them.
Link: https://lkml.kernel.org/r/20240813150758.855881-2-surenb@google.com
Fixes: d224eb0287 ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [6.10]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In several cases we are freeing pages which were not allocated using
common page allocators. For such cases, in order to keep allocation
accounting correct, we should clear the page tag to indicate that the page
being freed is expected to not have a valid allocation tag. Introduce
clear_page_tag_ref() helper function to be used for this.
Link: https://lkml.kernel.org/r/20240813150758.855881-1-surenb@google.com
Fixes: d224eb0287 ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [6.10]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Unaccepted memory is considered unusable free memory, which is not counted
as free on the zone watermark check. This causes get_page_from_freelist()
to accept more memory to hit the high watermark, but it creates problems
in the reclaim path.
The reclaim path encounters a failed zone watermark check and attempts to
reclaim memory. This is usually successful, but if there is little or no
reclaimable memory, it can result in endless reclaim with little to no
progress. This can occur early in the boot process, just after start of
the init process when the only reclaimable memory is the page cache of the
init executable and its libraries.
Make unaccepted memory free from watermark check point of view. This way
unaccepted memory will never be the trigger of memory reclaim. Accept
more memory in the get_page_from_freelist() if needed.
Link: https://lkml.kernel.org/r/20240809114854.3745464-2-kirill.shutemov@linux.intel.com
Fixes: dcdfdd40fa ("mm: Add support for unaccepted memory")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Jianxiong Gao <jxgao@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When handling a numa page fault, task_numa_fault() should be called by a
process that restores the page table of the faulted folio to avoid
duplicated stats counting. Commit c5b5a3dd2c ("mm: thp: refactor NUMA
fault handling") restructured do_huge_pmd_numa_page() and did not avoid
task_numa_fault() call in the second page table check after a numa
migration failure. Fix it by making all !pmd_same() return immediately.
This issue can cause task_numa_fault() being called more than necessary
and lead to unexpected numa balancing results (It is hard to tell whether
the issue will cause positive or negative performance impact due to
duplicated numa fault counting).
Link: https://lkml.kernel.org/r/20240809145906.1513458-3-ziy@nvidia.com
Fixes: c5b5a3dd2c ("mm: thp: refactor NUMA fault handling")
Reported-by: "Huang, Ying" <ying.huang@intel.com>
Closes: https://lore.kernel.org/linux-mm/87zfqfw0yw.fsf@yhuang6-desk2.ccr.corp.intel.com/
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When handling a numa page fault, task_numa_fault() should be called by a
process that restores the page table of the faulted folio to avoid
duplicated stats counting. Commit b99a342d4f ("NUMA balancing: reduce
TLB flush via delaying mapping on hint page fault") restructured
do_numa_page() and did not avoid task_numa_fault() call in the second page
table check after a numa migration failure. Fix it by making all
!pte_same() return immediately.
This issue can cause task_numa_fault() being called more than necessary
and lead to unexpected numa balancing results (It is hard to tell whether
the issue will cause positive or negative performance impact due to
duplicated numa fault counting).
Link: https://lkml.kernel.org/r/20240809145906.1513458-2-ziy@nvidia.com
Fixes: b99a342d4f ("NUMA balancing: reduce TLB flush via delaying mapping on hint page fault")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: "Huang, Ying" <ying.huang@intel.com>
Closes: https://lore.kernel.org/linux-mm/87zfqfw0yw.fsf@yhuang6-desk2.ccr.corp.intel.com/
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The __vmap_pages_range_noflush() assumes its argument pages** contains
pages with the same page shift. However, since commit e9c3cda4d8 ("mm,
vmalloc: fix high order __GFP_NOFAIL allocations"), if gfp_flags includes
__GFP_NOFAIL with high order in vm_area_alloc_pages() and page allocation
failed for high order, the pages** may contain two different page shifts
(high order and order-0). This could lead __vmap_pages_range_noflush() to
perform incorrect mappings, potentially resulting in memory corruption.
Users might encounter this as follows (vmap_allow_huge = true, 2M is for
PMD_SIZE):
kvmalloc(2M, __GFP_NOFAIL|GFP_X)
__vmalloc_node_range_noprof(vm_flags=VM_ALLOW_HUGE_VMAP)
vm_area_alloc_pages(order=9) ---> order-9 allocation failed and fallback to order-0
vmap_pages_range()
vmap_pages_range_noflush()
__vmap_pages_range_noflush(page_shift = 21) ----> wrong mapping happens
We can remove the fallback code because if a high-order allocation fails,
__vmalloc_node_range_noprof() will retry with order-0. Therefore, it is
unnecessary to fallback to order-0 here. Therefore, fix this by removing
the fallback code.
Link: https://lkml.kernel.org/r/20240808122019.3361-1-hailong.liu@oppo.com
Fixes: e9c3cda4d8 ("mm, vmalloc: fix high order __GFP_NOFAIL allocations")
Signed-off-by: Hailong Liu <hailong.liu@oppo.com>
Reported-by: Tangquan Zheng <zhengtangquan@oppo.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The memory_failure_cpu structure is a per-cpu structure. Access to its
content requires the use of get_cpu_var() to lock in the current CPU and
disable preemption. The use of a regular spinlock_t for locking purpose
is fine for a non-RT kernel.
Since the integration of RT spinlock support into the v5.15 kernel, a
spinlock_t in a RT kernel becomes a sleeping lock and taking a sleeping
lock in a preemption disabled context is illegal resulting in the
following kind of warning.
[12135.732244] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[12135.732248] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 270076, name: kworker/0:0
[12135.732252] preempt_count: 1, expected: 0
[12135.732255] RCU nest depth: 2, expected: 2
:
[12135.732420] Hardware name: Dell Inc. PowerEdge R640/0HG0J8, BIOS 2.10.2 02/24/2021
[12135.732423] Workqueue: kacpi_notify acpi_os_execute_deferred
[12135.732433] Call Trace:
[12135.732436] <TASK>
[12135.732450] dump_stack_lvl+0x57/0x81
[12135.732461] __might_resched.cold+0xf4/0x12f
[12135.732479] rt_spin_lock+0x4c/0x100
[12135.732491] memory_failure_queue+0x40/0xe0
[12135.732503] ghes_do_memory_failure+0x53/0x390
[12135.732516] ghes_do_proc.constprop.0+0x229/0x3e0
[12135.732575] ghes_proc+0xf9/0x1a0
[12135.732591] ghes_notify_hed+0x6a/0x150
[12135.732602] notifier_call_chain+0x43/0xb0
[12135.732626] blocking_notifier_call_chain+0x43/0x60
[12135.732637] acpi_ev_notify_dispatch+0x47/0x70
[12135.732648] acpi_os_execute_deferred+0x13/0x20
[12135.732654] process_one_work+0x41f/0x500
[12135.732695] worker_thread+0x192/0x360
[12135.732715] kthread+0x111/0x140
[12135.732733] ret_from_fork+0x29/0x50
[12135.732779] </TASK>
Fix it by using a raw_spinlock_t for locking instead.
Also move the pr_err() out of the lock critical section and after
put_cpu_ptr() to avoid indeterminate latency and the possibility of sleep
with this call.
[longman@redhat.com: don't hold percpu ref across pr_err(), per Miaohe]
Link: https://lkml.kernel.org/r/20240807181130.1122660-1-longman@redhat.com
Link: https://lkml.kernel.org/r/20240806164107.1044956-1-longman@redhat.com
Fixes: 0f383b6dc9 ("locking/spinlock: Provide RT variant")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix invalid access to pgdat during hot-remove operation:
ndctl users reported a GPF when trying to destroy a namespace:
$ ndctl destroy-namespace all -r all -f
Segmentation fault
dmesg:
Oops: general protection fault, probably for
non-canonical address 0xdffffc0000005650: 0000 [#1] PREEMPT SMP KASAN
PTI
KASAN: probably user-memory-access in range
[0x000000000002b280-0x000000000002b287]
CPU: 26 UID: 0 PID: 1868 Comm: ndctl Not tainted 6.11.0-rc1 #1
Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS
2.20.1 09/13/2023
RIP: 0010:mod_node_page_state+0x2a/0x110
cxl-test users report a GPF when trying to unload the test module:
$ modrpobe -r cxl-test
dmesg
BUG: unable to handle page fault for address: 0000000000004200
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 UID: 0 PID: 1076 Comm: modprobe Tainted: G O N 6.11.0-rc1 #197
Tainted: [O]=OOT_MODULE, [N]=TEST
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/15
RIP: 0010:mod_node_page_state+0x6/0x90
Currently, when memory is hot-plugged or hot-removed the accounting is
done based on the assumption that memmap is allocated from the same node
as the hot-plugged/hot-removed memory, which is not always the case.
In addition, there are challenges with keeping the node id of the memory
that is being remove to the time when memmap accounting is actually
performed: since this is done after remove_pfn_range_from_zone(), and
also after remove_memory_block_devices(). Meaning that we cannot use
pgdat nor walking though memblocks to get the nid.
Given all of that, account the memmap overhead system wide instead.
For this we are going to be using global atomic counters, but given that
memmap size is rarely modified, and normally is only modified either
during early boot when there is only one CPU, or under a hotplug global
mutex lock, therefore there is no need for per-cpu optimizations.
Also, while we are here rename nr_memmap to nr_memmap_pages, and
nr_memmap_boot to nr_memmap_boot_pages to be self explanatory that the
units are in page count.
[pasha.tatashin@soleen.com: address a few nits from David Hildenbrand]
Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240808213437.682006-4-pasha.tatashin@soleen.com
Fixes: 15995a3524 ("mm: report per-page metadata information")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/linux-cxl/CAHj4cs9Ax1=CoJkgBGP_+sNu6-6=6v=_L-ZBZY0bVLD3wUWZQg@mail.gmail.com
Reported-by: Alison Schofield <alison.schofield@intel.com>
Closes: https://lore.kernel.org/linux-mm/Zq0tPd2h6alFz8XF@aschofie-mobl2/#t
Tested-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Fan Ni <fan.ni@samsung.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
/proc/vmstat contains events and stats, events can only grow, but stats
can grow and shrink.
vmstat has the following:
-------------------------
NR_VM_ZONE_STAT_ITEMS: per-zone stats
NR_VM_NUMA_EVENT_ITEMS: per-numa events
NR_VM_NODE_STAT_ITEMS: per-numa stats
NR_VM_WRITEBACK_STAT_ITEMS: system-wide background-writeback and
dirty-throttling tresholds.
NR_VM_EVENT_ITEMS: system-wide events
-------------------------
Rename NR_VM_WRITEBACK_STAT_ITEMS to NR_VM_STAT_ITEMS, to track the
system-wide stats, we are going to add per-page metadata stats to this
category in the next patch.
Also delete unused writeback_stat_name().
Link: https://lkml.kernel.org/r/20240809191020.1142142-2-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240808213437.682006-3-pasha.tatashin@soleen.com
Fixes: 15995a3524 ("mm: report per-page metadata information")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Suggested-by: Yosry Ahmed <yosryahmed@google.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yi Zhang <yi.zhang@redhat.com>
Cc: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Fixes for memmap accounting", v4.
Memmap accounting provides us with observability of how much memory is
used for per-page metadata: i.e. "struct page"'s and "struct page_ext".
It also provides with information of how much was allocated using
boot allocator (i.e. not part of MemTotal), and how much was allocated
using buddy allocated (i.e. part of MemTotal).
This small series fixes a few problems that were discovered with the
original patch.
This patch (of 3):
When we fail to allocate the mmemmap in alloc_vmemmap_page_list(), do not
account any already-allocated pages: we're going to free all them before
we return from the function.
Link: https://lkml.kernel.org/r/20240809191020.1142142-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240808213437.682006-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240808213437.682006-2-pasha.tatashin@soleen.com
Fixes: 15995a3524 ("mm: report per-page metadata information")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
is_madv_discard did its check wrong. MADV_ flags are not bitwise,
they're normal sequential numbers. So, for instance:
behavior & (/* ... */ | MADV_REMOVE)
tagged both MADV_REMOVE and MADV_RANDOM (bit 0 set) as discard
operations.
As a result the kernel could erroneously block certain madvises (e.g
MADV_RANDOM or MADV_HUGEPAGE) on sealed VMAs due to them sharing bits
with blocked MADV operations (e.g REMOVE or WIPEONFORK).
This is obviously incorrect, so use a switch statement instead.
Link: https://lkml.kernel.org/r/20240807173336.2523757-1-pedro.falcato@gmail.com
Link: https://lkml.kernel.org/r/20240807173336.2523757-2-pedro.falcato@gmail.com
Fixes: 8be7258aad ("mseal: add mseal syscall")
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
Tested-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
we are *not* guaranteed that anything past the terminating NUL
is mapped (let alone initialized with anything sane).
Fixes: 0dea116876 ("cgroup: implement eventfd-based generic API for notifications")
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
aren't considered necessary for earlier kernels. 5 are MM and 4 are
non-MM. No identifiable theme here - please see the individual changelogs.
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Merge tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"Nine hotfixes. Five are cc:stable, the others either pertain to
post-6.10 material or aren't considered necessary for earlier kernels.
Five are MM and four are non-MM. No identifiable theme here - please
see the individual changelogs"
* tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
padata: Fix possible divide-by-0 panic in padata_mt_helper()
mailmap: update entry for David Heidelberg
memcg: protect concurrent access to mem_cgroup_idr
mm: shmem: fix incorrect aligned index when checking conflicts
mm: shmem: avoid allocating huge pages larger than MAX_PAGECACHE_ORDER for shmem
mm: list_lru: fix UAF for memory cgroup
kcov: properly check for softirq context
MAINTAINERS: Update LTP members and web
selftests: mm: add s390 to ARCH check
Commit 73f576c04b ("mm: memcontrol: fix cgroup creation failure after
many small jobs") decoupled the memcg IDs from the CSS ID space to fix the
cgroup creation failures. It introduced IDR to maintain the memcg ID
space. The IDR depends on external synchronization mechanisms for
modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace()
happen within css callback and thus are protected through cgroup_mutex
from concurrent modifications. However idr_remove() for mem_cgroup_idr
was not protected against concurrency and can be run concurrently for
different memcgs when they hit their refcnt to zero. Fix that.
We have been seeing list_lru based kernel crashes at a low frequency in
our fleet for a long time. These crashes were in different part of
list_lru code including list_lru_add(), list_lru_del() and reparenting
code. Upon further inspection, it looked like for a given object (dentry
and inode), the super_block's list_lru didn't have list_lru_one for the
memcg of that object. The initial suspicions were either the object is
not allocated through kmem_cache_alloc_lru() or somehow
memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but
returned success. No evidence were found for these cases.
Looking more deeply, we started seeing situations where valid memcg's id
is not present in mem_cgroup_idr and in some cases multiple valid memcgs
have same id and mem_cgroup_idr is pointing to one of them. So, the most
reasonable explanation is that these situations can happen due to race
between multiple idr_remove() calls or race between
idr_alloc()/idr_replace() and idr_remove(). These races are causing
multiple memcgs to acquire the same ID and then offlining of one of them
would cleanup list_lrus on the system for all of them. Later access from
other memcgs to the list_lru cause crashes due to missing list_lru_one.
Link: https://lkml.kernel.org/r/20240802235822.1830976-1-shakeel.butt@linux.dev
Fixes: 73f576c04b ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In the shmem_suitable_orders() function, xa_find() is used to check for
conflicts in the pagecache to select suitable huge orders. However, when
checking each huge order in every loop, the aligned index is calculated
from the previous iteration, which may cause suitable huge orders to be
missed.
We should use the original index each time in the loop to calculate a new
aligned index for checking conflicts to avoid this issue.
Link: https://lkml.kernel.org/r/07433b0f16a152bffb8cee34934a5c040e8e2ad6.1722404078.git.baolin.wang@linux.alibaba.com
Fixes: e7a2ab7b3b ("mm: shmem: add mTHP support for anonymous shmem")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Similar to commit d659b715e9 ("mm/huge_memory: avoid PMD-size page
cache if needed"), ARM64 can support 512MB PMD-sized THP when the base
page size is 64KB, which is larger than the maximum supported page cache
size MAX_PAGECACHE_ORDER.
This is not expected. To fix this issue, use THP_ORDERS_ALL_FILE_DEFAULT
for shmem to filter allowable huge orders.
[baolin.wang@linux.alibaba.com: remove comment, per Barry]
Link: https://lkml.kernel.org/r/c55d7ef7-78aa-4ed6-b897-c3e03a3f3ab7@linux.alibaba.com
[wangkefeng.wang@huawei.com: remove local `orders']
Link: https://lkml.kernel.org/r/87769ae8-b6c6-4454-925d-1864364af9c8@huawei.com
Link: https://lkml.kernel.org/r/117121665254442c3c7f585248296495e5e2b45c.1722404078.git.baolin.wang@linux.alibaba.com
Fixes: e7a2ab7b3b ("mm: shmem: add mTHP support for anonymous shmem")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Barry Song <21cnbao@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mem_cgroup_from_slab_obj() is supposed to be called under rcu lock or
cgroup_mutex or others which could prevent returned memcg from being
freed. Fix it by adding missing rcu read lock.
Found by code inspection.
[songmuchun@bytedance.com: only grab rcu lock when necessary, per Vlastimil]
Link: https://lkml.kernel.org/r/20240801024603.1865-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20240718083607.42068-1-songmuchun@bytedance.com
Fixes: 0a97c01cd2 ("list_lru: allow explicit memcg and NUMA node selection")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Merge tag 'slab-fixes-for-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab fix from Vlastimil Babka:
"Since v6.8 we've had a subtle breakage in SLUB with KFENCE enabled,
that can cause a crash. It hasn't been found earlier due to quite
specific conditions necessary (OOM during kmem_cache_alloc_bulk())"
* tag 'slab-fixes-for-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm, slub: do not call do_slab_free for kfence object
In 782f8906f8 the freeing of kfence objects was moved from deep
inside do_slab_free to the wrapper functions outside. This is a nice
change, but unfortunately it missed one spot in __kmem_cache_free_bulk.
This results in a crash like this:
BUG skbuff_head_cache (Tainted: G S B E ): Padding overwritten. 0xffff88907fea0f00-0xffff88907fea0fff @offset=3840
slab_err (mm/slub.c:1129)
free_to_partial_list (mm/slub.c:? mm/slub.c:4036)
slab_pad_check (mm/slub.c:864 mm/slub.c:1290)
check_slab (mm/slub.c:?)
free_to_partial_list (mm/slub.c:3171 mm/slub.c:4036)
kmem_cache_alloc_bulk (mm/slub.c:? mm/slub.c:4495 mm/slub.c:4586 mm/slub.c:4635)
napi_build_skb (net/core/skbuff.c:348 net/core/skbuff.c:527 net/core/skbuff.c:549)
All the other callers to do_slab_free appear to be ok.
Add a kfence_free check in __kmem_cache_free_bulk to avoid the crash.
Reported-by: Chris Mason <clm@meta.com>
Fixes: 782f8906f8 ("mm/slub: free KFENCE objects in slab_free_hook()")
Cc: stable@kernel.org
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics. The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.
These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:
- trivial duplicated macro definitions have been removed
Note that 'trivial' here means that it's obviously kernel code that
already included all the major kernel headers, and thus gets the new
generic MIN/MAX macros automatically.
- non-trivial duplicated macro definitions are guarded with #ifndef
This is the "yes, they define their own versions, but no, the include
situation is not entirely obvious, and maybe they don't get the
generic version automatically" case.
- strange use case #1
A couple of drivers decided that the way they want to describe their
versioning is with
#define MAJ 1
#define MIN 2
#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)
which adds zero value and I just did my Alexander the Great
impersonation, and rewrote that pointless Gordian knot as
#define DRV_VERSION "1.2"
instead.
- strange use case #2
A couple of drivers thought that it's a good idea to have a random
'MIN' or 'MAX' define for a value or index into a table, rather than
the traditional macro that takes arguments.
These values were re-written as C enum's instead. The new
function-line macros only expand when followed by an open
parenthesis, and thus don't clash with enum use.
Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.
Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
