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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- The series "Enable strict percpu address space checks" from Uros
Bizjak uses x86 named address space qualifiers to provide
compile-time checking of percpu area accesses.
This has caused a small amount of fallout - two or three issues were
reported. In all cases the calling code was found to be incorrect.
- The series "Some cleanup for memcg" from Chen Ridong implements some
relatively monir cleanups for the memcontrol code.
- The series "mm: fixes for device-exclusive entries (hmm)" from David
Hildenbrand fixes a boatload of issues which David found then using
device-exclusive PTE entries when THP is enabled. More work is
needed, but this makes thins better - our own HMM selftests now
succeed.
- The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
remove the z3fold and zbud implementations. They have been deprecated
for half a year and nobody has complained.
- The series "mm: further simplify VMA merge operation" from Lorenzo
Stoakes implements numerous simplifications in this area. No runtime
effects are anticipated.
- The series "mm/madvise: remove redundant mmap_lock operations from
process_madvise()" from SeongJae Park rationalizes the locking in the
madvise() implementation. Performance gains of 20-25% were observed
in one MADV_DONTNEED microbenchmark.
- The series "Tiny cleanup and improvements about SWAP code" from
Baoquan He contains a number of touchups to issues which Baoquan
noticed when working on the swap code.
- The series "mm: kmemleak: Usability improvements" from Catalin
Marinas implements a couple of improvements to the kmemleak
user-visible output.
- The series "mm/damon/paddr: fix large folios access and schemes
handling" from Usama Arif provides a couple of fixes for DAMON's
handling of large folios.
- The series "mm/damon/core: fix wrong and/or useless damos_walk()
behaviors" from SeongJae Park fixes a few issues with the accuracy of
kdamond's walking of DAMON regions.
- The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
Stoakes changes the interaction between framebuffer deferred-io and
core MM. No functional changes are anticipated - this is preparatory
work for the future removal of page structure fields.
- The series "mm/damon: add support for hugepage_size DAMOS filter"
from Usama Arif adds a DAMOS filter which permits the filtering by
huge page sizes.
- The series "mm: permit guard regions for file-backed/shmem mappings"
from Lorenzo Stoakes extends the guard region feature from its
present "anon mappings only" state. The feature now covers shmem and
file-backed mappings.
- The series "mm: batched unmap lazyfree large folios during
reclamation" from Barry Song cleans up and speeds up the unmapping
for pte-mapped large folios.
- The series "reimplement per-vma lock as a refcount" from Suren
Baghdasaryan puts the vm_lock back into the vma. Our reasons for
pulling it out were largely bogus and that change made the code more
messy. This patchset provides small (0-10%) improvements on one
microbenchmark.
- The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
improves" from SeongJae Park does some maintenance work on the DAMON
docs.
- The series "hugetlb/CMA improvements for large systems" from Frank
van der Linden addresses a pile of issues which have been observed
when using CMA on large machines.
- The series "mm/damon: introduce DAMOS filter type for unmapped pages"
from SeongJae Park enables users of DMAON/DAMOS to filter my the
page's mapped/unmapped status.
- The series "zsmalloc/zram: there be preemption" from Sergey
Senozhatsky teaches zram to run its compression and decompression
operations preemptibly.
- The series "selftests/mm: Some cleanups from trying to run them" from
Brendan Jackman fixes a pile of unrelated issues which Brendan
encountered while runnimg our selftests.
- The series "fs/proc/task_mmu: add guard region bit to pagemap" from
Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
determine whether a particular page is a guard page.
- The series "mm, swap: remove swap slot cache" from Kairui Song
removes the swap slot cache from the allocation path - it simply
wasn't being effective.
- The series "mm: cleanups for device-exclusive entries (hmm)" from
David Hildenbrand implements a number of unrelated cleanups in this
code.
- The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
implements a number of preparatoty cleanups to the GENERIC_PTDUMP
Kconfig logic.
- The series "mm/damon: auto-tune aggregation interval" from SeongJae
Park implements a feedback-driven automatic tuning feature for
DAMON's aggregation interval tuning.
- The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
preparation for implementing lazy mmu mode for arm64 to optimize
vmalloc.
- The series "mm/page_alloc: Some clarifications for migratetype
fallback" from Brendan Jackman reworks some commentary to make the
code easier to follow.
- The series "page_counter cleanup and size reduction" from Shakeel
Butt cleans up the page_counter code and fixes a size increase which
we accidentally added late last year.
- The series "Add a command line option that enables control of how
many threads should be used to allocate huge pages" from Thomas
Prescher does that. It allows the careful operator to significantly
reduce boot time by tuning the parallalization of huge page
initialization.
- The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
from Tang Yizhou fixes the tracing output from the dirty page
balancing code.
- The series "mm/damon: make allow filters after reject filters useful
and intuitive" from SeongJae Park improves the handling of allow and
reject filters. Behaviour is made more consistent and the documention
is updated accordingly.
- The series "Switch zswap to object read/write APIs" from Yosry Ahmed
updates zswap to the new object read/write APIs and thus permits the
removal of some legacy code from zpool and zsmalloc.
- The series "Some trivial cleanups for shmem" from Baolin Wang does as
it claims.
- The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
Alistair Popple regularizes the weird ZONE_DEVICE page refcount
handling in DAX, permittig the removal of a number of special-case
checks.
- The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
preparatoty refactoring and cleanup of the mremap() code.
- The series "mm: MM owner tracking for large folios (!hugetlb) +
CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
which we determine whether a large folio is known to be mapped
exclusively into a single MM.
- The series "mm/damon: add sysfs dirs for managing DAMOS filters based
on handling layers" from SeongJae Park adds a couple of new sysfs
directories to ease the management of DAMON/DAMOS filters.
- The series "arch, mm: reduce code duplication in mem_init()" from
Mike Rapoport consolidates many per-arch implementations of
mem_init() into code generic code, where that is practical.
- The series "mm/damon/sysfs: commit parameters online via
damon_call()" from SeongJae Park continues the cleaning up of sysfs
access to DAMON internal data.
- The series "mm: page_ext: Introduce new iteration API" from Luiz
Capitulino reworks the page_ext initialization to fix a boot-time
crash which was observed with an unusual combination of compile and
cmdline options.
- The series "Buddy allocator like (or non-uniform) folio split" from
Zi Yan reworks the code to split a folio into smaller folios. The
main benefit is lessened memory consumption: fewer post-split folios
are generated.
- The series "Minimize xa_node allocation during xarry split" from Zi
Yan reduces the number of xarray xa_nodes which are generated during
an xarray split.
- The series "drivers/base/memory: Two cleanups" from Gavin Shan
performs some maintenance work on the drivers/base/memory code.
- The series "Add tracepoints for lowmem reserves, watermarks and
totalreserve_pages" from Martin Liu adds some more tracepoints to the
page allocator code.
- The series "mm/madvise: cleanup requests validations and
classifications" from SeongJae Park cleans up some warts which
SeongJae observed during his earlier madvise work.
- The series "mm/hwpoison: Fix regressions in memory failure handling"
from Shuai Xue addresses two quite serious regressions which Shuai
has observed in the memory-failure implementation.
- The series "mm: reliable huge page allocator" from Johannes Weiner
makes huge page allocations cheaper and more reliable by reducing
fragmentation.
- The series "Minor memcg cleanups & prep for memdescs" from Matthew
Wilcox is preparatory work for the future implementation of memdescs.
- The series "track memory used by balloon drivers" from Nico Pache
introduces a way to track memory used by our various balloon drivers.
- The series "mm/damon: introduce DAMOS filter type for active pages"
from Nhat Pham permits users to filter for active/inactive pages,
separately for file and anon pages.
- The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
separates the proactive reclaim statistics from the direct reclaim
statistics.
- The series "mm/vmscan: don't try to reclaim hwpoison folio" from
Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
code.
* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
x86/mm: restore early initialization of high_memory for 32-bits
mm/vmscan: don't try to reclaim hwpoison folio
mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
selftests/mm: speed up split_huge_page_test
selftests/mm: uffd-unit-tests support for hugepages > 2M
docs/mm/damon/design: document active DAMOS filter type
mm/damon: implement a new DAMOS filter type for active pages
fs/dax: don't disassociate zero page entries
MM documentation: add "Unaccepted" meminfo entry
selftests/mm: add commentary about 9pfs bugs
fork: use __vmalloc_node() for stack allocation
docs/mm: Physical Memory: Populate the "Zones" section
xen: balloon: update the NR_BALLOON_PAGES state
hv_balloon: update the NR_BALLOON_PAGES state
balloon_compaction: update the NR_BALLOON_PAGES state
meminfo: add a per node counter for balloon drivers
mm: remove references to folio in __memcg_kmem_uncharge_page()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf try_alloc_pages() support from Alexei Starovoitov:
"The pull includes work from Sebastian, Vlastimil and myself with a lot
of help from Michal and Shakeel.
This is a first step towards making kmalloc reentrant to get rid of
slab wrappers: bpf_mem_alloc, kretprobe's objpool, etc. These patches
make page allocator safe from any context.
Vlastimil kicked off this effort at LSFMM 2024:
https://lwn.net/Articles/974138/
and we continued at LSFMM 2025:
https://lore.kernel.org/all/CAADnVQKfkGxudNUkcPJgwe3nTZ=xohnRshx9kLZBTmR_E1DFEg@mail.gmail.com/
Why:
SLAB wrappers bind memory to a particular subsystem making it
unavailable to the rest of the kernel. Some BPF maps in production
consume Gbytes of preallocated memory. Top 5 in Meta: 1.5G, 1.2G,
1.1G, 300M, 200M. Once we have kmalloc that works in any context BPF
map preallocation won't be necessary.
How:
Synchronous kmalloc/page alloc stack has multiple stages going from
fast to slow: cmpxchg16 -> slab_alloc -> new_slab -> alloc_pages ->
rmqueue_pcplist -> __rmqueue, where rmqueue_pcplist was already
relying on trylock.
This set changes rmqueue_bulk/rmqueue_buddy to attempt a trylock and
return ENOMEM if alloc_flags & ALLOC_TRYLOCK. It then wraps this
functionality into try_alloc_pages() helper. We make sure that the
logic is sane in PREEMPT_RT.
End result: try_alloc_pages()/free_pages_nolock() are safe to call
from any context.
try_kmalloc() for any context with similar trylock approach will
follow. It will use try_alloc_pages() when slab needs a new page.
Though such try_kmalloc/page_alloc() is an opportunistic allocator,
this design ensures that the probability of successful allocation of
small objects (up to one page in size) is high.
Even before we have try_kmalloc(), we already use try_alloc_pages() in
BPF arena implementation and it's going to be used more extensively in
BPF"
* tag 'bpf_try_alloc_pages' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
mm: Fix the flipped condition in gfpflags_allow_spinning()
bpf: Use try_alloc_pages() to allocate pages for bpf needs.
mm, bpf: Use memcg in try_alloc_pages().
memcg: Use trylock to access memcg stock_lock.
mm, bpf: Introduce free_pages_nolock()
mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation
locking/local_lock: Introduce localtry_lock_t
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Patch series "Adding Proactive Memory Reclaim Statistics".
These two patches are related to proactive memory reclaim.
Patch 1 Split proactive reclaim statistics from direct reclaim counters
and introduces new counters: pgsteal_proactive, pgdemote_proactive,
and pgscan_proactive.
Patch 2 Adds pswpin and pswpout items to the cgroup-v2 documentation.
This patch (of 2):
In proactive memory reclaim scenarios, it is necessary to accurately track
proactive reclaim statistics to dynamically adjust the frequency and
amount of memory being reclaimed proactively. Currently, proactive
reclaim is included in direct reclaim statistics, which can make these
direct reclaim statistics misleading.
Therefore, separate proactive reclaim memory from the direct reclaim
counters by introducing new counters: pgsteal_proactive,
pgdemote_proactive, and pgscan_proactive, to avoid confusion with direct
reclaim.
Link: https://lkml.kernel.org/r/20250318075833.90615-1-jiahao.kernel@gmail.com
Link: https://lkml.kernel.org/r/20250318075833.90615-2-jiahao.kernel@gmail.com
Signed-off-by: Hao Jia <jiahao1@lixiang.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This use of folios is misleading because these pages are not part of
a folio. Remove an unnecessary call to page_folio(), saving 58 bytes
of text in a Debian kernel build.
Link: https://lkml.kernel.org/r/20250314133617.138071-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We know that the passed in page is not part of a folio (it's a plain page
allocated with GFP_ACCOUNT), so we should get rid of the misleading
references to folios.
Introduce page_objcg() and page_set_objcg() helpers to make things more
clear.
Link: https://lkml.kernel.org/r/20250314133617.138071-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The last argument to split_page_memcg() is now always 0, so remove it,
effectively reverting commit b8791381d7ed.
Link: https://lkml.kernel.org/r/20250314133617.138071-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "Minor memcg cleanups & prep for memdescs", v2.
Separate the handling of accounted folios and GFP_ACCOUNT pages for easier
to understand code. For more detail, see
https://lore.kernel.org/linux-mm/Z9LwTOudOlCGny3f@casper.infradead.org/
This patch (of 5):
Folios always use memcg_data to refer to the mem_cgroup while pages
allocated with GFP_ACCOUNT have a pointer to the obj_cgroup. Since the
caller already knows what it has, split the function into two and then we
don't need to check.
Move the assignment of split folio memcg_data to the point where we set up
the other parts of the new folio. That leaves folio_split_memcg_refs()
just handling the memcg accounting.
Link: https://lkml.kernel.org/r/20250314133617.138071-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250314133617.138071-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We never charge the page counters of root memcg, so there is no need to
put root memcg in the memcg stock. At the moment, refill_stock() can be
called from try_charge_memcg(), obj_cgroup_uncharge_pages() and
mem_cgroup_uncharge_skmem().
The try_charge_memcg() and mem_cgroup_uncharge_skmem() are never called
with root memcg, so those are fine. However obj_cgroup_uncharge_pages()
can potentially call refill_stock() with root memcg if the objcg object
has been reparented over to the root memcg. Let's just avoid
refill_stock() from obj_cgroup_uncharge_pages() for root memcg.
Link: https://lkml.kernel.org/r/20250313054812.2185900-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhockoc@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The root memcg is never associated with a socket in mem_cgroup_sk_alloc,
so there is no need to check if the given memcg is root for the skmem
charging code path.
Link: https://lkml.kernel.org/r/20250228022354.2624249-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently page_counter tracks failcnt for counters used by v1 and v2
controllers. However failcnt is only exported for v1 deployment and thus
there is no need to maintain it in v2. The oom report does expose failcnt
for memory and swap in v2 but v2 already maintains MEMCG_MAX and
MEMCG_SWAP_MAX event counters which can be used.
Link: https://lkml.kernel.org/r/20250228075808.207484-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "page_counter cleanup and size reduction".
Commit c6f53ed8f213a ("mm, memcg: cg2 memory{.swap,}.peak write handlers")
accidently increased the size of struct page_counter. This series
rearrange the fields to reduce its size and also has some cleanups.
This patch (of 3):
Memcg-v1 does not support memory protection (min/low) and thus there is no
need to track protected memory usage for it.
Link: https://lkml.kernel.org/r/20250228075808.207484-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20250228075808.207484-2-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The interweaving of two entirely different swap accounting strategies has
been one of the more confusing parts of the memcg code. Split out the v1
code to clarify the implementation and a handful of callsites, and to
avoid building the v1 bits when !CONFIG_MEMCG_V1.
text data bss dec hex filename
39253 6446 4160 49859 c2c3 mm/memcontrol.o.old
38877 6382 4160 49419 c10b mm/memcontrol.o
Link: https://lkml.kernel.org/r/20250124054132.45643-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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6b611388b626 ("memcg-v1: remove charge move code") removed the remaining
v1 callers.
Link: https://lkml.kernel.org/r/20250124043859.18808-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add CONFIG_MEMCG_V1 for the 'local' functions, which are only used in
memcg v1, so that they won't be built for v2.
Link: https://lkml.kernel.org/r/20250124073514.2375622-5-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Finkel <davidf@vimeo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Factor out the 'replace_stock_objcg' function to make the code more
cohesive.
Link: https://lkml.kernel.org/r/20250124073514.2375622-4-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Finkel <davidf@vimeo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The 'free_mem_cgroup_per_node_info' function is used to free the
'mem_cgroup_per_node' struct. Using 'pn' as the input for the
free_mem_cgroup_per_node_info function will be much clearer. Call
'free_mem_cgroup_per_node_info' when 'alloc_mem_cgroup_per_node_info'
fails, to free 'pn' as a whole, which makes the code more cohesive.
Link: https://lkml.kernel.org/r/20250124073514.2375622-3-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Finkel <davidf@vimeo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "Some cleanup for memcg", v4.
This patch (of 4):
The 'OFP_PEAK_UNSET' has been defined, use it instead of '-1'.
Link: https://lkml.kernel.org/r/20250124073514.2375622-1-chenridong@huaweicloud.com
Link: https://lkml.kernel.org/r/20250124073514.2375622-2-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: David Finkel <davidf@vimeo.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently on cpu hotplug teardown, only memcg stock is drained but we
need to drain the obj stock as well otherwise we will miss the stats
accumulated on the target cpu as well as the nr_bytes cached. The stats
include MEMCG_KMEM, NR_SLAB_RECLAIMABLE_B & NR_SLAB_UNRECLAIMABLE_B. In
addition we are leaking reference to struct obj_cgroup object.
Link: https://lkml.kernel.org/r/20250310230934.2913113-1-shakeel.butt@linux.dev
Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 6769183166b3 removed the parameter of id from swap_cgroup_record()
and get the memcg id from mem_cgroup_id(folio_memcg(folio)). However, the
caller of it may update a different memcg's counter instead of
folio_memcg(folio).
E.g. in the caller of mem_cgroup_swapout(), @swap_memcg could be
different with @memcg and update the counter of @swap_memcg, but
swap_cgroup_record() records the wrong memcg's ID. When it is uncharged
from __mem_cgroup_uncharge_swap(), the swap counter will leak since the
wrong recorded ID.
Fix it by bringing the parameter of id back.
Link: https://lkml.kernel.org/r/20250306023133.44838-1-songmuchun@bytedance.com
Fixes: 6769183166b3 ("mm/swap_cgroup: decouple swap cgroup recording and clearing")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Kairui Song <kasong@tencent.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Teach memcg to operate under trylock conditions when spinning locks
cannot be used.
localtry_trylock might fail and this would lead to charge cache bypass
if the calling context doesn't allow spinning (gfpflags_allow_spinning).
In those cases charge the memcg counter directly and fail early if
that is not possible. This might cause a pre-mature charge failing
but it will allow an opportunistic charging that is safe from
try_alloc_pages path.
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20250222024427.30294-5-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
A softlockup issue was found with stress test:
watchdog: BUG: soft lockup - CPU#27 stuck for 26s! [migration/27:181]
CPU: 27 UID: 0 PID: 181 Comm: migration/27 6.14.0-rc2-next-20250210 #1
Stopper: multi_cpu_stop <- stop_machine_from_inactive_cpu
RIP: 0010:stop_machine_yield+0x2/0x10
RSP: 0000:ff4a0dcecd19be48 EFLAGS: 00000246
RAX: ffffffff89c0108f RBX: ff4a0dcec03afe44 RCX: 0000000000000000
RDX: ff1cdaaf6eba5808 RSI: 0000000000000282 RDI: ff1cda80c1775a40
RBP: 0000000000000001 R08: 00000011620096c6 R09: 7fffffffffffffff
R10: 0000000000000001 R11: 0000000000000100 R12: ff1cda80c1775a40
R13: 0000000000000000 R14: 0000000000000001 R15: ff4a0dcec03afe20
FS: 0000000000000000(0000) GS:ff1cdaaf6eb80000(0000)
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000025e2c2a001 CR4: 0000000000773ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
multi_cpu_stop+0x8f/0x100
cpu_stopper_thread+0x90/0x140
smpboot_thread_fn+0xad/0x150
kthread+0xc2/0x100
ret_from_fork+0x2d/0x50
The stress test involves CPU hotplug operations and memory control group
(memcg) operations. The scenario can be described as follows:
echo xx > memory.max cache_ap_online oom_reaper
(CPU23) (CPU50)
xx < usage stop_machine_from_inactive_cpu
for(;;) // all active cpus
trigger OOM queue_stop_cpus_work
// waiting oom_reaper
multi_cpu_stop(migration/xx)
// sync all active cpus ack
// waiting cpu23 ack
// CPU50 loops in multi_cpu_stop
waiting cpu50
Detailed explanation:
1. When the usage is larger than xx, an OOM may be triggered. If the
process does not handle with ths kill signal immediately, it will loop
in the memory_max_write.
2. When cache_ap_online is triggered, the multi_cpu_stop is queued to the
active cpus. Within the multi_cpu_stop function, it attempts to
synchronize the CPU states. However, the CPU23 didn't acknowledge
because it is stuck in a loop within the for(;;).
3. The oom_reaper process is blocked because CPU50 is in a loop, waiting
for CPU23 to acknowledge the synchronization request.
4. Finally, it formed cyclic dependency and lead to softlockup and dead
loop.
To fix this issue, add cond_resched() in the memory_max_write, so that it
will not block migration task.
Link: https://lkml.kernel.org/r/20250211081819.33307-1-chenridong@huaweicloud.com
Fixes: b6e6edcfa405 ("mm: memcontrol: reclaim and OOM kill when shrinking memory.max below usage")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
A soft lockup issue was found in the product with about 56,000 tasks were
in the OOM cgroup, it was traversing them when the soft lockup was
triggered.
watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066]
CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G
Hardware name: Huawei Cloud OpenStack Nova, BIOS
RIP: 0010:console_unlock+0x343/0x540
RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247
RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040
R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0
R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
vprintk_emit+0x193/0x280
printk+0x52/0x6e
dump_task+0x114/0x130
mem_cgroup_scan_tasks+0x76/0x100
dump_header+0x1fe/0x210
oom_kill_process+0xd1/0x100
out_of_memory+0x125/0x570
mem_cgroup_out_of_memory+0xb5/0xd0
try_charge+0x720/0x770
mem_cgroup_try_charge+0x86/0x180
mem_cgroup_try_charge_delay+0x1c/0x40
do_anonymous_page+0xb5/0x390
handle_mm_fault+0xc4/0x1f0
This is because thousands of processes are in the OOM cgroup, it takes a
long time to traverse all of them. As a result, this lead to soft lockup
in the OOM process.
To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks'
function per 1000 iterations. For global OOM, call
'touch_softlockup_watchdog' per 1000 iterations to avoid this issue.
Link: https://lkml.kernel.org/r/20241224025238.3768787-1-chenridong@huaweicloud.com
Fixes: 9cbb78bb3143 ("mm, memcg: introduce own oom handler to iterate only over its own threads")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The current implementation of swap cgroup tracking is a bit complex and
fragile:
On charging path, swap_cgroup_record always records an actual memcg id,
and it depends on the caller to make sure all entries passed in must
belong to one single folio. As folios are always charged or uncharged as
a whole, and always charged and uncharged in order, swap_cgroup doesn't
need an extra lock.
On uncharging path, swap_cgroup_record always sets the record to zero.
These entries won't be charged again until uncharging is done. So there
is no extra lock needed either. Worth noting that swap cgroup clearing
may happen without folio involved, eg. exiting processes will zap its
page table without swapin.
The xchg/cmpxchg provides atomic operations and barriers to ensure no
tearing or synchronization issue of these swap cgroup records.
It works but quite error-prone. Things can be much clear and robust by
decoupling recording and clearing into two helpers. Recording takes the
actual folio being charged as argument, and clearing always set the record
to zero, and refine the debug sanity checks to better reflect their usage
Benchmark even showed a very slight improvement as it saved some
extra arguments and lookups:
make -j96 with defconfig on tmpfs in 1.5G memory cgroup using 4k folios:
Before: sys 9617.23 (stdev 37.764062)
After : sys 9541.54 (stdev 42.973976)
make -j96 with defconfig on tmpfs in 2G memory cgroup using 64k folios:
Before: sys 7358.98 (stdev 54.927593)
After : sys 7337.82 (stdev 39.398956)
Link: https://lkml.kernel.org/r/20241218114633.85196-5-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Suggested-by: Chris Li <chrisl@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm/swap_cgroup: remove global swap cgroup lock", v3.
This series removes the global swap cgroup lock. The critical section of
this lock is very short but it's still a bottle neck for mass parallel
swap workloads.
Up to 10% performance gain for tmpfs build kernel test on a 48c96t system
under memory pressure, and no regression for other cases:
This patch (of 3):
mem_cgroup_uncharge_swap() includes a mem_cgroup_disabled() check,
so the caller doesn't need to check that.
Link: https://lkml.kernel.org/r/20241218114633.85196-1-ryncsn@gmail.com
Link: https://lkml.kernel.org/r/20241218114633.85196-2-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This patch fully removes the mem_cgroup_{try, commit, cancel}_charge
functions, as well as their hugetlb variants.
Link: https://lkml.kernel.org/r/20241211203951.764733-4-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This patch introduces mem_cgroup_charge_hugetlb which combines the logic
of mem_cgroup_hugetlb_try_charge / mem_cgroup_hugetlb_commit_charge and
removes the need for mem_cgroup_hugetlb_cancel_charge. It also reduces
the footprint of memcg in hugetlb code and consolidates all memcg related
error paths into one.
Link: https://lkml.kernel.org/r/20241211203951.764733-3-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "memcg/hugetlb: Rework memcg hugetlb charging", v3.
This series cleans up memcg's hugetlb charging logic by deprecating the
current memcg hugetlb try-charge + {commit, cancel} logic present in
alloc_hugetlb_folio. A single function mem_cgroup_charge_hugetlb takes
its place instead. This makes the code more maintainable by simplifying
the error path and reduces memcg's footprint in hugetlb logic.
This patch introduces a few changes in the hugetlb folio allocation
error path:
(a) Instead of having multiple return points, we consolidate them to
two: one for reaching the memcg limit or running out of memory
(-ENOMEM) and one for hugetlb allocation fails / limit being
reached (-ENOSPC).
(b) Previously, the memcg limit was checked before the folio is acquired,
meaning the hugeTLB folio isn't acquired if the limit is reached.
This patch performs the charging after the folio is reached, meaning
if memcg's limit is reached, the acquired folio is freed right away.
This patch builds on two earlier patch series: [2] which adds memcg
hugeTLB counters, and [3] which deprecates charge moving and removes the
last references to mem_cgroup_cancel_charge. The request for this cleanup
can be found in [2].
[1] https://lore.kernel.org/all/20231006184629.155543-1-nphamcs@gmail.com/
[2] https://lore.kernel.org/all/20241101204402.1885383-1-joshua.hahnjy@gmail.com/
[3] https://lore.kernel.org/linux-mm/20241025012304.2473312-1-shakeel.butt@linux.dev/
This patch (of 3):
This patch isolates the check for whether memcg accounts hugetlb. This
condition can only be true if the memcg mount option
memory_hugetlb_accounting is on, which includes hugetlb usage in
memory.current.
Link: https://lkml.kernel.org/r/20241211203951.764733-1-joshua.hahnjy@gmail.com
Link: https://lkml.kernel.org/r/20241211203951.764733-2-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This patch introduces a new counter to memory.stat that tracks hugeTLB
usage, only if hugeTLB accounting is done to memory.current. This feature
is enabled the same way hugeTLB accounting is enabled, via the
memory_hugetlb_accounting mount flag for cgroupsv2.
1. Why is this patch necessary?
Currently, memcg hugeTLB accounting is an opt-in feature [1] that adds
hugeTLB usage to memory.current. However, the metric is not reported in
memory.stat. Given that users often interpret memory.stat as a breakdown
of the value reported in memory.current, the disparity between the two
reports can be confusing. This patch solves this problem by including the
metric in memory.stat as well, but only if it is also reported in
memory.current (it would also be confusing if the value was reported in
memory.stat, but not in memory.current)
Aside from the consistency between the two files, we also see benefits in
observability. Userspace might be interested in the hugeTLB footprint of
cgroups for many reasons. For instance, system admins might want to
verify that hugeTLB usage is distributed as expected across tasks: i.e.
memory-intensive tasks are using more hugeTLB pages than tasks that don't
consume a lot of memory, or are seen to fault frequently. Note that this
is separate from wanting to inspect the distribution for limiting purposes
(in which case, hugeTLB controller makes more sense).
2. We already have a hugeTLB controller. Why not use that?
It is true that hugeTLB tracks the exact value that we want. In fact, by
enabling the hugeTLB controller, we get all of the observability benefits
that I mentioned above, and users can check the total hugeTLB usage,
verify if it is distributed as expected, etc.
With this said, there are 2 problems:
(a) They are still not reported in memory.stat, which means the
disparity between the memcg reports are still there.
(b) We cannot reasonably expect users to enable the hugeTLB controller
just for the sake of hugeTLB usage reporting, especially since
they don't have any use for hugeTLB usage enforcing [2].
3. Implementation Details:
In the alloc / free hugetlb functions, we call lruvec_stat_mod_folio
regardless of whether memcg accounts hugetlb. mem_cgroup_commit_charge
which is called from alloc_hugetlb_folio will set memcg for the folio only
if the CGRP_ROOT_MEMORY_HUGETLB_ACCOUNTING cgroup mount option is used, so
lruvec_stat_mod_folio accounts per-memcg hugetlb counters only if the
feature is enabled. Regardless of whether memcg accounts for hugetlb, the
newly added global counter is updated and shown in /proc/vmstat.
The global counter is added because vmstats is the preferred framework for
cgroup stats. It makes stat items consistent between global and cgroups.
It also provides a per-node breakdown, which is useful. Because it does
not use cgroup-specific hooks, we also keep generic MM code separate from
memcg code.
[1] https://lore.kernel.org/all/20231006184629.155543-1-nphamcs@gmail.com/
[2] Of course, we can't make a new patch for every feature that can be
duplicated. However, since the existing solution of enabling the
hugeTLB controller is an imperfect solution that still leaves a
discrepancy between memory.stat and memory.curent, I think that it
is reasonable to isolate the feature in this case.
Link: https://lkml.kernel.org/r/20241101204402.1885383-1-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Suggested-by: Nhat Pham <nphamcs@gmail.com>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently, every list_lru has a per-node lock that protects adding,
deletion, isolation, and reparenting of all list_lru_one instances
belonging to this list_lru on this node. This lock contention is heavy
when multiple cgroups modify the same list_lru.
This lock can be split into per-cgroup scope to reduce contention.
To achieve this, we need a stable list_lru_one for every cgroup. This
commit adds a lock to each list_lru_one and introduced a helper function
lock_list_lru_of_memcg, making it possible to pin the list_lru of a memcg.
Then reworked the reparenting process.
Reparenting will switch the list_lru_one instances one by one. By locking
each instance and marking it dead using the nr_items counter, reparenting
ensures that all items in the corresponding cgroup (on-list or not,
because items have a stable cgroup, see below) will see the list_lru_one
switch synchronously.
Objcg reparent is also moved after list_lru reparent so items will have a
stable mem cgroup until all list_lru_one instances are drained.
The only caller that doesn't work the *_obj interfaces are direct calls to
list_lru_{add,del}. But it's only used by zswap and that's also based on
objcg, so it's fine.
This also changes the bahaviour of the isolation function when LRU_RETRY
or LRU_REMOVED_RETRY is returned, because now releasing the lock could
unblock reparenting and free the list_lru_one, isolation function will
have to return withoug re-lock the lru.
prepare() {
mkdir /tmp/test-fs
modprobe brd rd_nr=1 rd_size=33554432
mkfs.xfs -f /dev/ram0
mount -t xfs /dev/ram0 /tmp/test-fs
for i in $(seq 1 512); do
mkdir "/tmp/test-fs/$i"
for j in $(seq 1 10240); do
echo TEST-CONTENT > "/tmp/test-fs/$i/$j"
done &
done; wait
}
do_test() {
read_worker() {
sleep 1
tar -cv "$1" &>/dev/null
}
read_in_all() {
cd "/tmp/test-fs" && ls
for i in $(seq 1 512); do
(exec sh -c 'echo "$PPID"') > "/sys/fs/cgroup/benchmark/$i/cgroup.procs"
read_worker "$i" &
done; wait
}
for i in $(seq 1 512); do
mkdir -p "/sys/fs/cgroup/benchmark/$i"
done
echo +memory > /sys/fs/cgroup/benchmark/cgroup.subtree_control
echo 512M > /sys/fs/cgroup/benchmark/memory.max
echo 3 > /proc/sys/vm/drop_caches
time read_in_all
}
Above script simulates compression of small files in multiple cgroups
with memory pressure. Run prepare() then do_test for 6 times:
Before:
real 0m7.762s user 0m11.340s sys 3m11.224s
real 0m8.123s user 0m11.548s sys 3m2.549s
real 0m7.736s user 0m11.515s sys 3m11.171s
real 0m8.539s user 0m11.508s sys 3m7.618s
real 0m7.928s user 0m11.349s sys 3m13.063s
real 0m8.105s user 0m11.128s sys 3m14.313s
After this commit (about ~15% faster):
real 0m6.953s user 0m11.327s sys 2m42.912s
real 0m7.453s user 0m11.343s sys 2m51.942s
real 0m6.916s user 0m11.269s sys 2m43.957s
real 0m6.894s user 0m11.528s sys 2m45.346s
real 0m6.911s user 0m11.095s sys 2m43.168s
real 0m6.773s user 0m11.518s sys 2m40.774s
Link: https://lkml.kernel.org/r/20241104175257.60853-6-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
No feature change, just change of code structure and fix comment.
The list lrus are not empty until memcg_reparent_list_lru_node() calls are
all done, so the comments in memcg_offline_kmem were slightly inaccurate.
Link: https://lkml.kernel.org/r/20241104175257.60853-4-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This tracepoint gives visibility on how often the flushing of memcg stats
occurs and contains info on whether it was forced, skipped, and the value
of stats updated. It can help with understanding how readers are affected
by having to perform the flush, and the effectiveness of the flush by
inspecting the number of stats updated. Paired with the recently added
tracepoints for tracing rstat updates, it can also help show correlation
where stats exceed thresholds frequently.
Link: https://lkml.kernel.org/r/20241029021106.25587-3-inwardvessel@gmail.com
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "memcg: tracepoint for flushing stats", v3.
This series adds new capability for understanding frequency and circumstances
behind flushing memcg stats.
This patch (of 2):
Change the name to something more consistent with others in the file and
use double unders to signify it is associated with the
mem_cgroup_flush_stats() API call. Additionally include a new flag that
call sites use to indicate a forced flush; skipping checks and flushing
unconditionally. There are no changes in functionality.
Link: https://lkml.kernel.org/r/20241029021106.25587-1-inwardvessel@gmail.com
Link: https://lkml.kernel.org/r/20241029021106.25587-2-inwardvessel@gmail.com
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Pick up e7ac4daeed91 ("mm: count zeromap read and set for swapout and
swapin") in order to move
mm: define obj_cgroup_get() if CONFIG_MEMCG is not defined
mm: zswap: modify zswap_compress() to accept a page instead of a folio
mm: zswap: rename zswap_pool_get() to zswap_pool_tryget()
mm: zswap: modify zswap_stored_pages to be atomic_long_t
mm: zswap: support large folios in zswap_store()
mm: swap: count successful large folio zswap stores in hugepage zswpout stats
mm: zswap: zswap_store_page() will initialize entry after adding to xarray.
mm: add per-order mTHP swpin counters
from mm-unstable into mm-stable.
|
|
When the proportion of folios from the zeromap is small, missing their
accounting may not significantly impact profiling. However, it's easy to
construct a scenario where this becomes an issue—for example, allocating
1 GB of memory, writing zeros from userspace, followed by MADV_PAGEOUT,
and then swapping it back in. In this case, the swap-out and swap-in
counts seem to vanish into a black hole, potentially causing semantic
ambiguity.
On the other hand, Usama reported that zero-filled pages can exceed 10% in
workloads utilizing zswap, while Hailong noted that some app in Android
have more than 6% zero-filled pages. Before commit 0ca0c24e3211 ("mm:
store zero pages to be swapped out in a bitmap"), both zswap and zRAM
implemented similar optimizations, leading to these optimized-out pages
being counted in either zswap or zRAM counters (with pswpin/pswpout also
increasing for zRAM). With zeromap functioning prior to both zswap and
zRAM, userspace will no longer detect these swap-out and swap-in actions.
We have three ways to address this:
1. Introduce a dedicated counter specifically for the zeromap.
2. Use pswpin/pswpout accounting, treating the zero map as a standard
backend. This approach aligns with zRAM's current handling of
same-page fills at the device level. However, it would mean losing the
optimized-out page counters previously available in zRAM and would not
align with systems using zswap. Additionally, as noted by Nhat Pham,
pswpin/pswpout counters apply only to I/O done directly to the backend
device.
3. Count zeromap pages under zswap, aligning with system behavior when
zswap is enabled. However, this would not be consistent with zRAM, nor
would it align with systems lacking both zswap and zRAM.
Given the complications with options 2 and 3, this patch selects
option 1.
We can find these counters from /proc/vmstat (counters for the whole
system) and memcg's memory.stat (counters for the interested memcg).
For example:
$ grep -E 'swpin_zero|swpout_zero' /proc/vmstat
swpin_zero 1648
swpout_zero 33536
$ grep -E 'swpin_zero|swpout_zero' /sys/fs/cgroup/system.slice/memory.stat
swpin_zero 3905
swpout_zero 3985
This patch does not address any specific zeromap bug, but the missing
swpout and swpin counts for zero-filled pages can be highly confusing and
may mislead user-space agents that rely on changes in these counters as
indicators. Therefore, we add a Fixes tag to encourage the inclusion of
this counter in any kernel versions with zeromap.
Many thanks to Kanchana for the contribution of changing
count_objcg_event() to count_objcg_events() to support large folios[1],
which has now been incorporated into this patch.
[1] https://lkml.kernel.org/r/20241001053222.6944-5-kanchana.p.sridhar@intel.com
Link: https://lkml.kernel.org/r/20241107011246.59137-1-21cnbao@gmail.com
Fixes: 0ca0c24e3211 ("mm: store zero pages to be swapped out in a bitmap")
Co-developed-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Hailong Liu <hailong.liu@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently mem_cgroup_css_rstat_flush() is used to flush the per-CPU
statistics from a specified CPU into the global statistics of the
memcg. It processes three kinds of data in three for loops using exactly
the same method. Therefore, the for loop can be factored out and may
make the code more clean.
Link: https://lkml.kernel.org/r/20241026093407.310955-1-xiujianfeng@huaweicloud.com
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The memcg v1's charge move feature has been deprecated. All the places
using the memcg move lock, have stopped using it as they don't need the
protection any more. Let's proceed to remove all the locking code related
to charge moving.
Link: https://lkml.kernel.org/r/20241025012304.2473312-7-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The memcg-v1 charge move feature has been deprecated completely and let's
remove the relevant code as well.
Link: https://lkml.kernel.org/r/20241025012304.2473312-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Previously the seq_buf used for accumulating the memory.stat output was
sized at PAGE_SIZE. But the amount of output is invariant to PAGE_SIZE;
If 4K is enough on a 4K page system, then it should also be enough on a
64K page system, so we can save 60K on the static buffer used in
mem_cgroup_print_oom_meminfo(). Let's make it so.
This also has the beneficial side effect of removing a place in the code
that assumed PAGE_SIZE is a compile-time constant. So this helps our
quest towards supporting boot-time page size selection.
Link: https://lkml.kernel.org/r/20241021130027.3615969-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The memcg stats are maintained in rstat infrastructure which provides very
fast updates side and reasonable read side. However memcg added plethora
of stats and made the read side, which is cgroup rstat flush, very slow.
To solve that, threshold was added in the memcg stats read side i.e. no
need to flush the stats if updates are within the threshold.
This threshold based improvement worked for sometime but more stats were
added to memcg and also the read codepath was getting triggered in the
performance sensitive paths which made threshold based ratelimiting
ineffective. We need more visibility into the hot and cold stats i.e.
stats with a lot of updates. Let's add trace to get that visibility.
[shakeel.butt@linux.dev: use unsigned long type for memcg_rstat_events, per Yosry]
Link: https://lkml.kernel.org/r/20241015213721.3804209-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20241010003550.3695245-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: JP Kobryn <inwardvessel@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In proactive memory reclamation scenarios, it is necessary to estimate the
pswpin and pswpout metrics of the cgroup to determine whether to continue
reclaiming anonymous pages in the current batch. This patch will collect
these metrics and expose them.
[linuszeng@tencent.com: v2]
Link: https://lkml.kernel.org/r/20240830082244.156923-1-jingxiangzeng.cas@gmail.com
Li nk: https://lkml.kernel.org/r/20240913084453.3605621-1-jingxiangzeng.cas@gmail.com
Link: https://lkml.kernel.org/r/20240830082244.156923-1-jingxiangzeng.cas@gmail.com
Signed-off-by: Jingxiang Zeng <linuszeng@tencent.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Recent changes are putting more pressure on THP deferred split queues:
under load revealing long-standing races, causing list_del corruptions,
"Bad page state"s and worse (I keep BUGs in both of those, so usually
don't get to see how badly they end up without). The relevant recent
changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin,
improved swap allocation, and underused THP splitting.
Before fixing locking: rename misleading folio_undo_large_rmappable(),
which does not undo large_rmappable, to folio_unqueue_deferred_split(),
which is what it does. But that and its out-of-line __callee are mm
internals of very limited usability: add comment and WARN_ON_ONCEs to
check usage; and return a bool to say if a deferred split was unqueued,
which can then be used in WARN_ON_ONCEs around safety checks (sparing
callers the arcane conditionals in __folio_unqueue_deferred_split()).
Just omit the folio_unqueue_deferred_split() from free_unref_folios(), all
of whose callers now call it beforehand (and if any forget then bad_page()
will tell) - except for its caller put_pages_list(), which itself no
longer has any callers (and will be deleted separately).
Swapout: mem_cgroup_swapout() has been resetting folio->memcg_data 0
without checking and unqueueing a THP folio from deferred split list;
which is unfortunate, since the split_queue_lock depends on the memcg
(when memcg is enabled); so swapout has been unqueueing such THPs later,
when freeing the folio, using the pgdat's lock instead: potentially
corrupting the memcg's list. __remove_mapping() has frozen refcount to 0
here, so no problem with calling folio_unqueue_deferred_split() before
resetting memcg_data.
That goes back to 5.4 commit 87eaceb3faa5 ("mm: thp: make deferred split
shrinker memcg aware"): which included a check on swapcache before adding
to deferred queue, but no check on deferred queue before adding THP to
swapcache. That worked fine with the usual sequence of events in reclaim
(though there were a couple of rare ways in which a THP on deferred queue
could have been swapped out), but 6.12 commit dafff3f4c850 ("mm: split
underused THPs") avoids splitting underused THPs in reclaim, which makes
swapcache THPs on deferred queue commonplace.
Keep the check on swapcache before adding to deferred queue? Yes: it is
no longer essential, but preserves the existing behaviour, and is likely
to be a worthwhile optimization (vmstat showed much more traffic on the
queue under swapping load if the check was removed); update its comment.
Memcg-v1 move (deprecated): mem_cgroup_move_account() has been changing
folio->memcg_data without checking and unqueueing a THP folio from the
deferred list, sometimes corrupting "from" memcg's list, like swapout.
Refcount is non-zero here, so folio_unqueue_deferred_split() can only be
used in a WARN_ON_ONCE to validate the fix, which must be done earlier:
mem_cgroup_move_charge_pte_range() first try to split the THP (splitting
of course unqueues), or skip it if that fails. Not ideal, but moving
charge has been requested, and khugepaged should repair the THP later:
nobody wants new custom unqueueing code just for this deprecated case.
The 87eaceb3faa5 commit did have the code to move from one deferred list
to another (but was not conscious of its unsafety while refcount non-0);
but that was removed by 5.6 commit fac0516b5534 ("mm: thp: don't need care
deferred split queue in memcg charge move path"), which argued that the
existence of a PMD mapping guarantees that the THP cannot be on a deferred
list. As above, false in rare cases, and now commonly false.
Backport to 6.11 should be straightforward. Earlier backports must take
care that other _deferred_list fixes and dependencies are included. There
is not a strong case for backports, but they can fix cornercases.
Link: https://lkml.kernel.org/r/8dc111ae-f6db-2da7-b25c-7a20b1effe3b@google.com
Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware")
Fixes: dafff3f4c850 ("mm: split underused THPs")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Recent changes are putting more pressure on THP deferred split queues:
under load revealing long-standing races, causing list_del corruptions,
"Bad page state"s and worse (I keep BUGs in both of those, so usually
don't get to see how badly they end up without). The relevant recent
changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin,
improved swap allocation, and underused THP splitting.
The new unlocked list_del_init() in deferred_split_scan() is buggy. I
gave bad advice, it looks plausible since that's a local on-stack list,
but the fact is that it can race with a third party freeing or migrating
the preceding folio (properly unqueueing it with refcount 0 while holding
split_queue_lock), thereby corrupting the list linkage.
The obvious answer would be to take split_queue_lock there: but it has a
long history of contention, so I'm reluctant to add to that. Instead,
make sure that there is always one safe (raised refcount) folio before, by
delaying its folio_put(). (And of course I was wrong to suggest updating
split_queue_len without the lock: leave that until the splice.)
And remove two over-eager partially_mapped checks, restoring those tests
to how they were before: if uncharge_folio() or free_tail_page_prepare()
finds _deferred_list non-empty, it's in trouble whether or not that folio
is partially_mapped (and the flag was already cleared in the latter case).
Link: https://lkml.kernel.org/r/81e34a8b-113a-0701-740e-2135c97eb1d7@google.com
Fixes: dafff3f4c850 ("mm: split underused THPs")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Along with the usual shower of singleton patches, notable patch series
in this pull request are:
- "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
- "Some cleanups for shmem" from Baolin Wang. No functional changes -
mode code reuse, better function naming, logic simplifications.
- "mm: some small page fault cleanups" from Josef Bacik. No
functional changes - code cleanups only.
- "Various memory tiering fixes" from Zi Yan. A small fix and a
little cleanup.
- "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
- "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
Butt. This is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at
all used 16k. Useful for some system tuning things, but
partivularly useful for "the dynamic kernel stack project".
- "kmemleak: support for percpu memory leak detect" from Pavel
Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.
- "mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
- "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
David Hildenbrand. Improves PTE/PMD splitlock detection, makes
powerpc/8xx work correctly by design rather than by accident.
- "mm: remove arch_make_page_accessible()" from David Hildenbrand.
Some folio conversions which make arch_make_page_accessible()
unneeded.
- "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
Finkel. Cleans up and fixes our handling of the resetting of the
cgroup/process peak-memory-use detector.
- "Make core VMA operations internal and testable" from Lorenzo
Stoakes. Rationalizaion and encapsulation of the VMA manipulation
APIs. With a view to better enable testing of the VMA functions,
even from a userspace-only harness.
- "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
issues in the zswap global shrinker, resulting in improved
performance.
- "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
in some missing info in /proc/zoneinfo.
- "mm: replace follow_page() by folio_walk" from David Hildenbrand.
Code cleanups and rationalizations (conversion to folio_walk())
resulting in the removal of follow_page().
- "improving dynamic zswap shrinker protection scheme" from Nhat
Pham. Some tuning to improve zswap's dynamic shrinker. Significant
reductions in swapin and improvements in performance are shown.
- "mm: Fix several issues with unaccepted memory" from Kirill
Shutemov. Improvements to the new unaccepted memory feature,
- "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
DAX PUDs. This was missing, although nobody seems to have notied
yet.
- "Introduce a store type enum for the Maple tree" from Sidhartha
Kumar. Cleanups and modest performance improvements for the maple
tree library code.
- "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
more cgroup v1 remnants away from the v2 memcg code.
- "memcg: initiate deprecation of v1 features" from Shakeel Butt.
Adds various warnings telling users that memcg v1 features are
deprecated.
- "mm: swap: mTHP swap allocator base on swap cluster order" from
Chris Li. Greatly improves the success rate of the mTHP swap
allocation.
- "mm: introduce numa_memblks" from Mike Rapoport. Moves various
disparate per-arch implementations of numa_memblk code into generic
code.
- "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
- "support large folio swap-out and swap-in for shmem" from Baolin
Wang. With this series we no longer split shmem large folios into
simgle-page folios when swapping out shmem.
- "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
performance improvements and code reductions for gigantic folios.
- "support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
- "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
- "Increase the number of bits available in page_type" from Matthew
Wilcox. Increases the number of bits available in page_type!
- "Simplify the page flags a little" from Matthew Wilcox. Many legacy
page flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
- "mm: store zero pages to be swapped out in a bitmap" from Usama
Arif. An optimization which permits us to avoid writing/reading
zero-filled zswap pages to backing store.
- "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
window which occurs when a MAP_FIXED operqtion is occurring during
an unrelated vma tree walk.
- "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
the vma_merge() functionality, making ot cleaner, more testable and
better tested.
- "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
Minor fixups of DAMON selftests and kunit tests.
- "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
Code cleanups and folio conversions.
- "Shmem mTHP controls and stats improvements" from Ryan Roberts.
Cleanups for shmem controls and stats.
- "mm: count the number of anonymous THPs per size" from Barry Song.
Expose additional anon THP stats to userspace for improved tuning.
- "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
folio conversions and removal of now-unused page-based APIs.
- "replace per-quota region priorities histogram buffer with
per-context one" from SeongJae Park. DAMON histogram
rationalization.
- "Docs/damon: update GitHub repo URLs and maintainer-profile" from
SeongJae Park. DAMON documentation updates.
- "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
improve related doc and warn" from Jason Wang: fixes usage of page
allocator __GFP_NOFAIL and GFP_ATOMIC flags.
- "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
This was overprovisioning THPs in sparsely accessed memory areas.
- "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
Add support for zram run-time compression algorithm tuning.
- "mm: Care about shadow stack guard gap when getting an unmapped
area" from Mark Brown. Fix up the various arch_get_unmapped_area()
implementations to better respect guard areas.
- "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
of mem_cgroup_iter() and various code cleanups.
- "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
- "resource: Fix region_intersects() vs add_memory_driver_managed()"
from Huang Ying. Fix a bug in region_intersects() for systems with
CXL memory.
- "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
a couple more code paths to correctly recover from the encountering
of poisoned memry.
- "mm: enable large folios swap-in support" from Barry Song. Support
the swapin of mTHP memory into appropriately-sized folios, rather
than into single-page folios"
* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
zram: free secondary algorithms names
uprobes: turn xol_area->pages[2] into xol_area->page
uprobes: introduce the global struct vm_special_mapping xol_mapping
Revert "uprobes: use vm_special_mapping close() functionality"
mm: support large folios swap-in for sync io devices
mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
set_memory: add __must_check to generic stubs
mm/vma: return the exact errno in vms_gather_munmap_vmas()
memcg: cleanup with !CONFIG_MEMCG_V1
mm/show_mem.c: report alloc tags in human readable units
mm: support poison recovery from copy_present_page()
mm: support poison recovery from do_cow_fault()
resource, kunit: add test case for region_intersects()
resource: make alloc_free_mem_region() works for iomem_resource
mm: z3fold: deprecate CONFIG_Z3FOLD
vfio/pci: implement huge_fault support
mm/arm64: support large pfn mappings
mm/x86: support large pfn mappings
...
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large folios
With large folios swap-in, we might need to uncharge multiple entries all
together, add nr argument in mem_cgroup_swapin_uncharge_swap().
For the existing two users, just pass nr=1.
Link: https://lkml.kernel.org/r/20240908232119.2157-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: Chris Li <chrisl@kernel.org>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gao Xiang <xiang@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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A clean up to make variable names more clear and to improve code
readability.
No functional change.
Link: https://lkml.kernel.org/r/20240905003058.1859929-6-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently, if multiple reclaimers raced on the same position, the
reclaimers which detect the race will still reclaim from the same memcg.
Instead, the reclaimers which detect the race should move on to the next
memcg in the hierarchy.
So, in the case where multiple traversals race, jump back to the start of
the mem_cgroup_iter() function to find the next memcg in the hierarchy to
reclaim from.
Link: https://lkml.kernel.org/r/20240905003058.1859929-5-kinseyho@google.com
Reported-by: syzbot+e099d407346c45275ce9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/000000000000817cf10620e20d33@google.com/
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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The generation number in struct mem_cgroup_reclaim_iter should be
incremented on every round-trip. Currently, it is possible for a
concurrent reclaimer to jump in at the end of the hierarchy, causing a
traversal restart (resetting the iteration position) without incrementing
the generation number.
By resetting the position without incrementing the generation, it's
possible for another ongoing mem_cgroup_iter() thread to walk the tree
twice.
Move the traversal restart such that the generation number is
incremented before the restart.
Link: https://lkml.kernel.org/r/20240905003058.1859929-4-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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To obtain the pointer to the next memcg position, mem_cgroup_iter()
currently holds css->refcnt during memcg traversal only to put css->refcnt
at the end of the routine. This isn't necessary as an rcu_read_lock is
already held throughout the function. The use of the RCU read lock with
css_next_descendant_pre() guarantees that sibling linkage is safe without
holding a ref on the passed-in @css.
Remove css->refcnt usage during traversal by leveraging RCU.
Link: https://lkml.kernel.org/r/20240905003058.1859929-3-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently folio->_deferred_list is used to keep track of partially_mapped
folios that are going to be split under memory pressure. In the next
patch, all THPs that are faulted in and collapsed by khugepaged are also
going to be tracked using _deferred_list.
This patch introduces a pageflag to be able to distinguish between
partially mapped folios and others in the deferred_list at split time in
deferred_split_scan. Its needed as __folio_remove_rmap decrements
_mapcount, _large_mapcount and _entire_mapcount, hence it won't be
possible to distinguish between partially mapped folios and others in
deferred_split_scan.
Eventhough it introduces an extra flag to track if the folio is partially
mapped, there is no functional change intended with this patch and the
flag is not useful in this patch itself, it will become useful in the next
patch when _deferred_list has non partially mapped folios.
Link: https://lkml.kernel.org/r/20240830100438.3623486-5-usamaarif642@gmail.com
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Cc: Alexander Zhu <alexlzhu@fb.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuang Zhai <zhais@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Shuang Zhai <szhai2@cs.rochester.edu>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The ability to observe the demotion and promotion decisions made by the
kernel on a per-cgroup basis is important for monitoring and tuning
containerized workloads on machines equipped with tiered memory.
Different containers in the system may experience drastically different
memory tiering actions that cannot be distinguished from the global
counters alone.
For example, a container running a workload that has a much hotter memory
accesses will likely see more promotions and fewer demotions, potentially
depriving a colocated container of top tier memory to such an extent that
its performance degrades unacceptably.
For another example, some containers may exhibit longer periods between
data reuse, causing much more numa_hint_faults than numa_pages_migrated.
In this case, tuning hot_threshold_ms may be appropriate, but the signal
can easily be lost if only global counters are available.
In the long term, we hope to introduce per-cgroup control of promotion and
demotion actions to implement memory placement policies in tiering.
This patch set adds seven counters to memory.stat in a cgroup:
numa_pages_migrated, numa_pte_updates, numa_hint_faults, pgdemote_kswapd,
pgdemote_khugepaged, pgdemote_direct and pgpromote_success. pgdemote_*
and pgpromote_success are also available in memory.numa_stat.
count_memcg_events_mm() is added to count multiple event occurrences at
once, and get_mem_cgroup_from_folio() is added because we need to get a
reference to the memcg of a folio before it's migrated to track
numa_pages_migrated. The accounting of PGDEMOTE_* is moved to
shrink_inactive_list() before being changed to per-cgroup.
[kaiyang2@cs.cmu.edu: add documentation of the memcg counters in cgroup-v2.rst]
Link: https://lkml.kernel.org/r/20240814235122.252309-1-kaiyang2@cs.cmu.edu
Link: https://lkml.kernel.org/r/20240814174227.30639-1-kaiyang2@cs.cmu.edu
Signed-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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