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Pull more MM updates from Andrew Morton:
- "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
(Lorenzo Stoakes)
Index MAP_PRIVATE file-backed folios by their anonymous page offset
to resolve confusion around reverse mapping for zeroed and CoW'd
file-backed memory.
Use this new VMA anonymous page offset tracking to eliminate index
conflicts and lay the foundation for scalable CoW performance
improvements.
- "promote mapped executable folios after first usage for MGLRU"
(Baolin Wang)
Make MGLRU's protection of mapped executable file folios more
reliable. Follow the classical LRU's logic, promoting mapped
executable file folios after their first usage to give executable
code a better chance to stay in memory and improve workload
performance.
- "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
Chen)
Fix per-node proactive reclaim interface's ignoring the swappiness
parameter when CONFIG_MEMCG is disabled by consolidating
sc_swappiness() into a single function that checks
proactive_swappiness regardless of kernel configuration.
- "mm/vmscan: reduce lru_lock contention via vmstat-derived
scan-balance cost" (Usama Arif)
Reduce lru_lock contention in the reclaim path by deriving
scan-balance costs from vmstat counters rather than lock-acquired
producer updates.
Read and decay these cost signals on the reclaim side under a
dedicated per-lruvec lock, reducing total LRU lock wait time by over
60% without impacting scan throughput.
- "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)
Fix two low-risk zram bugs which Sashiko spotted in drive-by review.
- "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
memcg" (Zi Yan)
Fix xas_split_alloc() by enabling target folio memcg charging during
splits and adding the missing __GFP_ACCOUNT flag for proper XArray
node memory accounting.
- "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)
Replace hardcoded binary names in selftests/mm/.gitignore with a
generic pattern-matching rule to automatically ignore generated test
files and avoid manual updates when adding new tests.
- "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)
Make the incompatibility between FLATMEM and NUMA explicit in
mm/Kconfig and remove the unused pgdat_page_ext_init() function.
- "zram: fix zstd error paths and add parameter validation" (Haoqin
Huang)
Clean up zram compression backends by removing redundant error
cleanup, adding parameter and dictionary validation, auto-prefixing
algorithm error logs, and resetting parameters prior to
reinitialization.
- "zram: fix stale scan bounds after reinitialization" (Longlong Xia)
Prevent out-of-bounds slot accesses during concurrent zram resets by
moving table scan bound calculations under dev_lock in
writeback_store() and read_block_state().
- "add anon mTHP collapse test cases" (Baolin Wang)
Extend selftests helper functions to support arbitrary page orders
and add new test cases and options for mTHP collapse in khugepaged.
- "selftests/mm: Handle unsupported and transient test conditions"
(Muhammad Usama Anjum)
Update MM selftests to report a SKIP status instead of a failure when
required kernel or filesystem features are unsupported, while adding
retry logic for transient page migration errors.
- "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)
Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
and extend shrink_memcg() to support batch writeback for improved
writeback efficiency.
- "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
Baghdasaryan)
Introduce an IOCTL-based binary interface for memory allocation
profiling that enables kernel-side filtering before per-CPU counter
aggregation.
This eliminates the text-parsing overhead of /proc/allocinfo and
provides up to a 20x speedup by transferring only filtered allocation
data to userspace.
- "better block swap batching and a different take on swap_ops v5"
(Christoph Hellwig)
Refactor block swap I/O to use swap_iocb for batching instead of
single-bio requests and rebase the swap_ops interface, achieving
faster swap throughput during kernel builds.
- "mm: kmemleak: reduce transient false positives by confirming leaks"
(Catalin Marinas)
Reduce false-positive kmemleak reports by combining two kmemleak
enhancements that add a second confirmation scan and a configurable
minimum unreferenced scan count module parameter.
- "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
(Breno Leitao)
Auto-scanning kernels can generate false-positive memory leak reports
on single scans, so this patch defaults min_unref_scans to 2 when
CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
confirming scan.
- "swap_ops updates" (Christoph Hellwig)
Batching I/O for synchronous swap devices causes performance
regressions and filesystem-based swap suffers from double-indirection
overhead. This series resolves both issues by reintroducing per-folio
writes for synchronous swap and allowing filesystems to directly
export their own swap_ops.
- "mm/khugepaged: several cleanups" (Nico Pache)
khugepaged accumulated redundant state-checking patterns and outdated
comments following mTHP integration. Introduce dedicated helpers for
PTE validation and event counting while refreshing the internal
documentation.
- "maple_tree: lock checking and clean ups" (Liam Howlett)
Syzbot reports incorrectly blame memory management exit paths for
locking bugs, maple tree erase operations risk allocation failures
without gfp flags and internal documentation lacks clarity.
Improve lock error detection, update docs, fix race and allocation
edge cases and optimize erase allocations using a fallback to
GFP_KERNEL | GFP_NOFAIL.
* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
memcg: move LRU size accounting on reparenting instead of copying it
mm/vmscan: fix comment logic in balance_pgdat
maple_tree: add helper mas_make_walkable()
maple_tree: avoid extra gap calculation
maple_tree: fix argument name in header
maple_tree: change two GFP flags in tests
maple_tree: document erase and allocations better
maple_tree: avoid mas_erase() and mtree_erase() failures
maple_tree: document that erase may use GFP_KERNEL for allocations
maple_tree: catch race in mas_alloc_cyclic()
maple_tree: add bulk parent set helper
maple_tree: micro optimisation of mas_wr_store_type()
maple_tree: optimise mas_wr_node_store() when not in rcu mode
maple_tree: use prefetched value in mas_wr_store_type()
maple_tree: clarify comments on mas_nomem()
maple_tree: drop MAPLE_ALLOC_SLOTS
maple_tree: drop dead code from mas_extend_spanning_null()
maple_tree: documentation fix
maple_tree: add write lock checking with lockdep sequence numbers
...
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test_no_kmem_bypass() needs to read /sys/kernel/debug/zswap/stored_pages
via get_zswap_stored_pages() to verify that compressed pages are charged
to the memcg.
When running in an environment where debugfs is not mounted or
CONFIG_DEBUG_FS is disabled, get_zswap_stored_pages() fails, causing the
loop to terminate early and report a false negative (KSFT_FAIL).
Selftests should not fail if debugfs is unavailable, and it should print a
message when it is skipped.
While I'm here, also add a warning message if the test is being skipped
due to totalram size and make the check for totalram more readable.
[akpm@linux-foundation.org: clarify debugfs-unavailable error message]
Link: https://lore.kernel.org/20260812050848.848882-1-wfelipe@google.com
Link: https://lore.kernel.org/20260811051434.3805648-1-wfelipe@google.com
Signed-off-by: Wilson Felipe Pereira <wfelipe@google.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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test_cgcore_lesser_ns_open runs as root throughout and never changes its
euid, so chowning the two cgroup.procs files to a non-root uid has no
effect on the test.
The ENOENT the test expects comes from the cgroup namespace delegation
check in cgroup_procs_write_permission(): the source and destination
cgroups must both be descendants of the namespace root captured at open
time. That check does not depend on file ownership. In addition, the
permission check only examines the common ancestor's cgroup.procs file
(the test root here), which the chown calls do not touch.
Remove the redundant chown calls and the now unused test_euid and
cg_test_a_procs variables.
Signed-off-by: Shaojie Sun <sunshaojie@kylinos.cn>
Reviewed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The cpuset partition root state selftest checks several CPU hotplug
transitions. If writing to a CPU online file fails, the helper still
runs pause afterwards and returns the status of pause instead of the
failed write.
This hides the real hotplug failure and can make later checks run
against expectations for a transition that never happened. Move the
write before the bookkeeping and return when it fails, so callers can
observe the hotplug error and the test does not record a CPU as offline
unless the offline operation actually succeeded.
Also change the O* command handler in set_ctrl_state() to use
"eval $COMM $REDIRECT" like all other handlers. The previous version
set COMM but still called write_cpu_online directly, bypassing the
redirect that captures stderr for error reporting.
Changes since v1:
- Use eval $COMM $REDIRECT in the O* handler instead of calling
write_cpu_online directly (Waiman Long)
Fixes: a8c52eba880a ("kselftest/cgroup: Add cpuset v2 partition root state test")
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Add a test case to REMOTE_TEST_MATRIX covering the bug fixed by
commit 345f40166694 ("cgroup/cpuset: Return only actually allocated
CPUs during partition invalidation"). The test verifies that when a
sibling partition root changes its cpuset.cpus to overlap with another
partition root, only actually allocated CPUs (effective_xcpus) are
returned to the parent, not all CPUs in cpus_allowed.
Signed-off-by: Shaojie Sun <sunshaojie@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The cpuset selftests use awk -e to parse cgroup mount points. This
works with gawk, but mawk rejects the option. In test_cpuset_prs.sh,
this leaves CGROUP2 empty and causes the test to skip as if cgroup v2
were not mounted. The same non-portable invocation exists in the cpuset
v1 hotplug test.
The scripts only need to pass a single awk program. Use the standard awk
invocation without -e so mount point detection works with awk
implementations that do not support the gawk extension.
Fixes: a8c52eba880a ("kselftest/cgroup: Add cpuset v2 partition root state test")
Fixes: 812c5945bdb8 ("cgroup/cpuset: Add test_cpuset_v1_hp.sh")
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
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In test_cpucg_nice, after the child process exits, user_usec is
read from cpu.stat but the value is not checked. Add a sanity check
to ensure user_usec > 0, analogous to test_cpucg_stats(), so that
the test fails early if CPU usage wasn't properly accounted.
Signed-off-by: Shaojie Sun <sunshaojie@kylinos.cn>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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With commit 98149f542530 ("selftests/cgroup: Add test for cpuset affinity
on controller disable"), sashiko [1] reported 3 different issues with
the new test_cpuset_affinity_on_controller_disable() test.
1) `cpu_set_equal` iterates over mask bytes instead of bits, ignoring
CPUs >= 8.
2) Thread synchronization logic allows the main thread to read
uninitialized stack memory, causing test flakiness.
3) Test fails instead of skipping gracefully on uniprocessor systems
or when CPU 1 is unavailable.
Fix the reported issues by:
1) Iterates over the bit size of the mask.
2) Test the new ready flag for each thread to end the wait
on the conditional variable and eliminate the now unneeded
AFFINITY_THREAD_A_READY and AFFINITY_THREADS_READY test phases.
3) Return KSFT_SKIP on "cpuset.cpus" setting failure.
[1] https://sashiko.dev/#/patchset/20260712235510.373125-1-longman%40redhat.com
Fixes: 98149f542530 ("selftests/cgroup: Add test for cpuset affinity on controller disable")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The test_cgcore_no_internal_process_constraint_on_threads test has two
back-to-back cg_enter_current(root) calls in its cleanup path.
A single cg_enter_current() call atomically migrates the entire thread
group to the target cgroup even for multi-threaded processes, and this
test creates no extra threads or child processes that would require a
second migration attempt. The second call is a harmless no-op once the
process is already in the root cgroup, but it is redundant and
inconsistent with the cleanup logic used in all other cgroup core
selftest cases.
Remove the duplicate call to clean up the code. No functional change is
intended.
Signed-off-by: Jian Guo <guojian@kylinos.cn>
Acked-by: Michal Koutný <mkoutny@suse.com>
Tested-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Add a new selftest that exposes a bug in cpuset_attach() where thread
CPU affinity is not properly updated when the cpuset controller is
disabled in a threaded cgroup hierarchy.
The test creates a threaded cgroup hierarchy with two child cgroups
(A and B) having different cpuset.cpus constraints:
- Parent: cpuset.cpus=0-1
- Child A: cpuset.cpus=0-1
- Child B: cpuset.cpus=1 (restricted to CPU 1 only)
A multithreaded process is created with threads placed in different
cgroups. When the cpuset controller is disabled on the parent, thread
affinities should be updated to match the parent's cpuset.
Expected behavior:
- thread_a affinity: {0-1} before and after (unchanged)
- thread_b affinity: {1} before, {0-1} after (expanded)
Current buggy behavior:
- thread_b affinity remains {1} after controller disable
Assisted-by: Claude:claude-sonnet-4-5
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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main() in test_hugetlb_memcg never calls ksft_print_header(),
ksft_set_plan(), or ksft_finished(), so its output has no TAP plan and is
not valid TAP, unlike the sibling test_memcontrol and test_kmem tests.
Add the header/plan/finished calls following the same pattern.
Signed-off-by: Song Hu <husong@kylinos.cn>
Reviewed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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For lower HZ values a quota of 1000us is much lower than the amount
of microseconds per tick which makes the tests test_cpucg_max and
test_cpugc_max_nested fail. Increase the test duration to accommodate
for lower HZ values.
Link: https://lore.kernel.org/lkml/20260625203307.1114538-1-joest@redhat.com/
Signed-off-by: Joe Simmons-Talbott <joest@redhat.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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As reported by sashiko [1], cpuset_hotplug_update_tasks() may perform
unnecessary task iteration and updating of tasks' CPU and node masks
when mems_allowed and/or cpus_allowed are not set in cpuset v2. It is
due to the fact that the temporary new_cpus and new_mems masks do not
inherit parent's effective_cpus/mems when they are empty which is the
expected behavior for cpuset v2 since commit 4ec22e9c5a90 ("cpuset:
Enable cpuset controller in default hierarchy").
Fix that and avoid unnecessary work by enhancing
compute_effective_cpumask() to add the empty cpumask check
and inheriting the parent's versions if empty when in v2. A new
compute_effective_nodemask() helper is also added to perform a similar
function for new effective_mems.
Add new test_cpuset_prs.sh test cases to confirm that effective_cpus
will inherit the parent's version if cpuset.cpus is empty.
[1] https://sashiko.dev/#/patchset/20260621032816.1806773-1-longman%40redhat.com
Suggested-by: Ridong Chen <ridong.chen@linux.dev>
Fixes: 4ec22e9c5a90 ("cpuset: Enable cpuset controller in default hierarchy")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Pull MM updates from Andrew Morton:
- "selftests/mm: clean up build output and verbosity" (Li Wang)
Remove some noise from the MM selftests build
- "mm: Free contiguous order-0 pages efficiently" (Ryan Roberts)
Speed up the freeing of a batch of 0-order pages by first scanning
them for coalescing opportunities. This is applicable to vfree() and
to the releasing of frozen pages
- "mm/damon: introduce DAMOS failed region quota charge ratio"
(SeongJae Park)
Address a DAMOS usability issue: The DAMOS quota often exhausts
prematurely because it charges for all memory attempted, causing slow
and inconsistent performance when actions fail on unreclaimable
memory.
To fix this, a new feature lets users set a smaller, flexible quota
charge ratio (via a numerator and denominator) for failed regions.
Since failed actions cause less overhead, reducing their quota cost
ensures more predictable and efficient DAMOS processing
- "selftests/cgroup: improve zswap tests robustness and support large
page sizes" (Li Wang)
Fix various spurious failures and improves the overall robustness of
the cgroup zswap selftests
- "fix MAP_DROPPABLE not supported errno" (Anthony Yznaga)
Fix an issue in the mlock selftests on arm32
- "mm: huge_memory: clean up defrag sysfs with shared" (Breno Leitao)
Some maintenance work in the huge_memory code
- "treewide: fixup gfp_t printks" (Brendan Jackman)
Use the special vprintf() gfp_t conversion in various places
- "mm: Fix vmemmap optimization accounting and initialization" (Muchun
Song)
Fix several bugs in the vmemmap optimization, mainly around incorrect
page accounting and memmap initialization in the DAX and memory
hotplug paths. It also fixes pageblock migratetype initialization and
struct page initialization for ZONE_DEVICE compound pages
- "mm/damon: repost non-hotfix reviewed patches in damon/next tree"
A sprinkle of unrelated minor bugfixes for DAMON
- "mm: remove page_mapped()" (David Hildenbrand)
Remove this function from the tree, replacing it with folio_mapped()
- "mm/damon: let DAMON be paused and resumed" (SeongJae Park)
Allow DAMON to be paused and resumed without losing its current state
- "kasan: hw_tags: Disable tagging for stack and page-tables" (Muhammad
Usama Anjum)
Simplify and speed up kasan by removing its ineffective tagging of
stacks and page tables
- "mm/damon/reclaim,lru_sort: monitor all system rams by default"
(SeongJae Park)
Simplify deployment on diverse hardware like NUMA systems by updating
DAMON_RECLAIM and DAMON_LRU_SORT to automatically monitor the
physical address range covering all System RAM areas by default,
replacing the overly restrictive behavior that only targeted the
single largest memory block to save on negligible overhead
- "mm/damon/sysfs: document filters/ directory as deprecated" (SeongJae
Park)
Update some DAMON docs
- "mm: use spinlock guards for zone lock" (Dmitry Ilvokhin)
Switch zone->lock handling over to using the guard() mechanisms
- "mm/filemap: tighten mmap_miss hit accounting" (fujunjie)
Fix a flaw where the mmap_miss counter over-credited page cache hits
during fault-arounds and page-fault retries. This results in
significant reduction of redundant synchronous mmap readahead I/O,
drastically cutting down execution time and gigabytes read for sparse
random or strided memory access workloads
- "selftests/cgroup: Fix false positive failures in test_percpu_basic"
(Li Wang)
Fix a couple of false-positives in the cgroup kmem selftests
- "mm/damon/reclaim: support monitoring intervals auto-tuning"
(SeongJae Park)
Add a new parameter to DAMON permitting DAMON_RECLAIM to
automatically tune DAMON's sampling and aggregation intervals
- "mm/damon/stat: add kdamond_pid parameter" (SeongJae Park)
Change DAMON_STAT to provide the pid of its kdamond
- "mm/kmemleak: dedupe verbose scan output" (Breno Leitao)
Remove large amounts of duplicated backtraces from the verbose-mode
kmemleak output
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 1)" (David
Hildenbrand)
Reduce our use of CONFIG_HAVE_BOOTMEM_INFO_NODE, with a view to
removing it entirely in a later series
- "mm/damon: validate min_region_size to be power of 2" (Liew Rui Yan)
Prevent users from passing a non-power-of-2 value of `addr_unit', as
this later results in undesirable behavior
- "mm: document read_pages and simplify usage" (Frederick Mayle)
- "tools/mm/page-types: Fix misc bugs" (Ye Liu)
Fix three issues in tools/mm/page-types.c
- "mm: misc cleanups from __GFP_UNMAPPED series" (Brendan Jackman)
Implement several cleanups in the page allocator and related code
- "mm, swap: swap table phase IV: unify allocation" (Kairui Song)
Unify the allocation and charging of anon and shmem swap in folios,
provides better synchronization, consolidates the metadata
management, hence dropping the static array and map, and improves
performance
- "mm/damon: introduce data attributes monitoring" (SeongJae Park(
Extend DAMON to monitor general data attributes other than accesses
- "mm/vmalloc: free unused pages on vrealloc() shrink" (Shivam Kalra)
Implement the TODO in vrealloc() to unmap and free unused pages when
shrinking across a page boundary
- "mm/damon: documentation and comment fixes" (niecheng)
- "remove mmap_action success, error hooks" (Lorenzo Stoakes)
Eliminate custom hooks from mmap_action by removing the problematic
success_hook which allowed drivers to improperly access uninitialized
VMAs. It replaces the error_hook with a simple error-code field and
updates the memory char driver accordingly
- "mm/damon: minor improvements for code readability and tests"
(SeongJae Park)
- "mm/damon: fix macro arguments and clarify quota goals doc" (Maksym
Shcherba)
- "userfaultfd: merge fs/userfaultfd.c into mm/userfaultfd.c" (Mike
Rapoport)
- "mm/mglru: improve reclaim loop and dirty folio" (Kairui Song and
others)
Clean up and slightly improves MGLRU's reclaim loop and dirty
writeback handling. Large performance improvements are measured
- "use vma locks for proc/pid/{smaps|numa_maps} reads" (Suren
Baghdasaryan)
Use per-vma locks when reading /proc/pid/smaps and numa_maps similar
to reduce contention on central mmap_lock
- "refactors thpsize_shmem_enabled_store() and thpsize_shmem_enabled_show()"
(Ran Xiaokai)
Some cleanup work in the THP code
- "selftests/memfd: fix compilation warnings" (Konstantin Khorenko)
Fix a few build glitches in the memfd selftest code.
- "memcg: shrink obj_stock_pcp and cache multiple objcgs" (Shakeel
Butt)
Resolve a 68% performance regression caused by NUMA-node cache
thrashing around struct obj_stock_pcp by shrinking its existing
fields and expanding it into a multi-slot array that caches up to
five obj_cgroup pointers per CPU, allowing per-node variants of the
same memcg to coexist within a single 64-byte cache line.
- "zram: writeback fixes" (Sergey Senozhatsky)
address a couple of unrelated zram writeback issues
- "mm: switch THP shrinker to list_lru" (Johannes Weiner)
Resolve NUMA-awareness issues and streamlines callsite interaction by
refactoring and extending the list_lru API to completely replace the
complex, open-coded deferred split queue for Transparent Huge Pages
- "mm: improve large folio readahead for exec memory" (Usama Arif)
Improve large-folio readahead on systems like 64K-page arm64 by
preventing the mmap_miss check from permanently disabling
target-oriented VM_EXEC readahead, and by generalizing the
force_thp_readahead gate to support mappings with any usefully large
maximum folio order under the cache cap.
- "userfaultfd/pagemap: pre-existing fixes" (Kiryl Shutsemau)
Fix a bunch of minor issues in the userfaultfd/pagemap, all of which
were flagged by Sashiko review of proposed new material
- "mm/sparse-vmemmap: Provide generic vmemmap_set_pmd() and
vmemmap_check_pmd()" (Muchun Song)
Provide generic versions of these two functions so the four
arch-specific implementations can be removed.
- "mm/swap, PM: hibernate: fix swapoff race in uswsusp by pinning swap
device" (Youngjun Park)
Address a uswsusp-vs-swapoff race and reduces the swap device
reference taking/releasing frequency.
- "mm/hmm: A fix and a selftest" (Dev Jain)
* tag 'mm-stable-2026-06-18-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
selftests/mm/hmm-tests: test pagemap reads of PMD device-private entries
fs/proc/task_mmu: do not warn on seeing non-migration pmd entry
lib/test_hmm: check alloc_page_vma() return value and handle OOM
mm/compaction: cap compact_gap() at COMPACT_CLUSTER_MAX
mm/swap: remove redundant swap device reference in alloc/free
mm/swap, PM: hibernate: fix swapoff race in uswsusp by pinning swap device
mm/filemap: use folio_next_index() for start
vmalloc: fix NULL pointer dereference in is_vm_area_hugepages()
sparc/mm: drop vmemmap_check_pmd helper and use generic code
loongarch/mm: drop vmemmap_check_pmd helper and use generic code
riscv/mm: drop vmemmap_pmd helpers and use generic code
arm64/mm: drop vmemmap_pmd helpers and use generic code
mm/sparse-vmemmap: provide generic vmemmap_set_pmd() and vmemmap_check_pmd()
rust: page: mark Page::nid as inline
userfaultfd: build __VMA_UFFD_FLAGS from config-gated masks
userfaultfd: gate must_wait writability check on pte_present()
mm/huge_memory: preserve pmd_swp_uffd_wp on device-private PMD downgrade
fs/proc/task_mmu: fix hugetlb self-deadlock in pagemap_scan_pte_hole()
fs/proc/task_mmu: use huge_page_size() in pagemap_scan_hugetlb_entry()
fs/proc/task_mmu: fix make_uffd_wp_huge_pte() prot-update race
...
|
|
Pull cgroup updates from Tejun Heo:
- Last cycle deferred css teardown on cgroup removal until the cgroup
depopulated, so a css is not taken offline while tasks can still
reference it. Disabling a controller through cgroup.subtree_control
still had the same problem. This reworks the deferral from per-cgroup
to per-css so that path is covered too.
- New RDMA controller monitoring files: rdma.peak for per-device peak
usage and rdma.events / rdma.events.local for resource-limit
exhaustion. The max-limit parser was rewritten, fixing two input
parsing bugs.
- cpuset: fix a sched-domain leak on the domain-rebuild failure path
and skip a redundant hardwall ancestor scan on v2.
- Misc: pair the remaining lockless cgroup.max.* reads with WRITE_ONCE,
assorted selftest robustness fixes, and doc path corrections.
* tag 'cgroup-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (22 commits)
cgroup: Migrate tasks to the root css when a controller is rebound
docs: cgroup: Fix stale source file paths
cgroup/cpuset: Free sched domains on rebuild guard failure
cgroup: pair max limit READ_ONCE() with WRITE_ONCE()
selftests/cgroup: enable memory controller in hugetlb memcg test
cgroup/rdma: Drop unnecessary READ_ONCE() on event counters
cgroup: Defer kill_css_finish() in cgroup_apply_control_disable()
cgroup: Add per-subsys-css kill_css_finish deferral
cgroup: Move populated counters to cgroup_subsys_state
cgroup: Annotate unlocked nr_populated_* accesses with READ_ONCE/WRITE_ONCE
cgroup: Inline cgroup_has_tasks() in cgroup.h
cgroup/rdma: document rdma.peak, rdma.events and rdma.events.local
cgroup/rdma: add rdma.events.local for per-cgroup allocation failure attribution
cgroup/rdma: add rdma.events to track resource limit exhaustion
cgroup/rdma: add rdma.peak for per-device peak usage tracking
selftests/cgroup: check malloc return value in alloc_anon functions
cgroup/cpuset: Skip hardwall ancestor scan in cpuset v2 in cpuset_current_node_allowed()
selftests/cgroup: fix misleading debug message in test_cgfreezer_time_child
selftests/cgroup: fix child process escaping to parent cleanup in test_cpucg_nice
selftests/cgroup: Add NULL check after malloc in cgroup_util.c
...
|
|
test_percpu_basic() currently compares memory.current against only
memory.stat:percpu after creating 1000 child cgroups.
Observed failure:
#./test_kmem
ok 1 test_kmem_basic
ok 2 test_kmem_memcg_deletion
ok 3 test_kmem_proc_kpagecgroup
ok 4 test_kmem_kernel_stacks
ok 5 test_kmem_dead_cgroups
memory.current 11530240
percpu 8440000
not ok 6 test_percpu_basic
That assumption is too strict: child cgroup creation also allocates
slab-backed metadata, so memory.current is expected to be larger than
percpu alone. One visible path is:
cgroup_mkdir()
cgroup_create()
cgroup_addrm_file()
cgroup_add_file()
__kernfs_create_file()
__kernfs_new_node()
kmem_cache_zalloc()
These kernfs allocations are charged as slab and show up in
memory.stat:slab.
Update the check to compare memory.current against (percpu + slab)
within MAX_VMSTAT_ERROR, and print slab/delta in the failure message to
improve diagnostics.
Link: https://lore.kernel.org/20260501022058.18024-3-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sayali Patil <sayalip@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "selftests/cgroup: Fix false positive failures in
test_percpu_basic", v2.
This patch series addresses two separate issues that cause false
positive failures in the test_percpu_basic test within the cgroup
kmem selftests.
The first issue stems from a hardcoded assumption about the system
page size, which breaks the test on architectures with larger page
sizes.
The second issue is an overly strict memory check that fails to
account for the slab metadata allocated during cgroup creation.
This patch (of 2):
MAX_VMSTAT_ERROR uses a hardcoded page size of 4096, which assumes 4K
pages. This causes test_percpu_basic to fail on systems where the kernel
is configured with a larger page size, such as aarch64 systems using 16K
or 64K pages, where the maximum permissible discrepancy between
memory.current and percpu charges is proportionally larger.
Replace the hardcoded 4096 with sysconf(_SC_PAGESIZE) to correctly derive
the page size at runtime regardless of the underlying architecture or
kernel configuration.
Link: https://lore.kernel.org/20260501022058.18024-1-li.wang@linux.dev
Link: https://lore.kernel.org/20260501022058.18024-2-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Sayali Patil <sayalip@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
zswap writeback is asynchronous, but test_zswap.c checks writeback
counters immediately after reclaim/trigger paths. On some platforms (e.g.
ppc64le), this can race with background writeback and cause spurious
failures even when behavior is correct.
Add wait_for_writeback() to poll get_cg_wb_count() with a bounded
timeout, and use it in:
test_zswap_writeback_one() when writeback is expected
test_no_invasive_cgroup_shrink() for the wb_group check
This keeps the original before/after assertion style while making the
tests robust against writeback completion latency.
No test behavior change, selftest stability improvement only.
Link: https://lore.kernel.org/20260424040059.12940-9-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In attempt_writeback(), a memsize of 4M only covers 64 pages on 64K page
size systems. When memory.reclaim is called, the kernel prefers
reclaiming clean file pages (binary, libc, linker, etc.) over swapping
anonymous pages. With only 64 pages of anonymous memory, the reclaim
target can be largely or entirely satisfied by dropping file pages,
resulting in very few or zero anonymous pages being pushed into zswap.
This causes zswap_usage to be extremely small or zero, making
zswap_usage/4 insufficient to create meaningful writeback pressure. The
test then fails because no writeback is triggered.
On 4K page size systems this is not an issue because 4M covers 1024
pages, and file pages are a small fraction of the reclaim target.
Fix this by:
- Always allocating 1024 pages regardless of page size. This ensures
enough anonymous pages to reliably populate zswap and trigger
writeback, while keeping the original 4M allocation on 4K systems.
- Setting zswap.max to zswap_usage/4 instead of zswap_usage/2 to
create stronger writeback pressure, ensuring reclaim reliably
triggers writeback even on large page size systems.
=== Error Log ===
# uname -rm
6.12.0-211.el10.ppc64le ppc64le
# getconf PAGESIZE
65536
# ./test_zswap
TAP version 13
1..7
ok 1 test_zswap_usage
ok 2 test_swapin_nozswap
ok 3 test_zswapin
not ok 4 test_zswap_writeback_enabled
...
Link: https://lore.kernel.org/20260424040059.12940-8-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Yosry Ahmed <yosry@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
test_no_invasive_cgroup_shrink sets up two cgroups: wb_group, which is
expected to trigger zswap writeback, and a control group (renamed to
zw_group), which should only have pages sitting in zswap without any
writeback.
There are two problems with the current test:
1) The data patterns are reversed. wb_group uses allocate_bytes(), which
writes only a single byte per page — trivially compressible,
especially by zstd — so compressed pages fit within zswap.max and
writeback is never triggered. Meanwhile, the control group uses
getrandom() to produce hard-to-compress data, but it is the group
that does *not* need writeback.
2) The test uses fixed sizes (10K zswap.max, 10MB allocation) that are
too small on systems with large PAGE_SIZE (e.g. 64K), failing to
build enough memory pressure to trigger writeback reliably.
Fix both issues by:
- Swapping the data patterns: fill wb_group pages with partially
random data (getrandom for page_size/4 bytes) to resist compression
and trigger writeback, and fill zw_group pages with simple repeated
data to stay compressed in zswap.
- Making all size parameters PAGE_SIZE-aware: set allocation size to
PAGE_SIZE * 1024, memory.zswap.max to PAGE_SIZE, and memory.max to
allocation_size / 2 for both cgroups.
- Allocating memory inline instead of via cg_run() so the pages
remain resident throughout the test.
=== Error Log ===
# getconf PAGESIZE
65536
# ./test_zswap
TAP version 13
...
ok 5 test_zswap_writeback_disabled
ok 6 # SKIP test_no_kmem_bypass
not ok 7 test_no_invasive_cgroup_shrink
Link: https://lore.kernel.org/20260424040059.12940-7-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
test_zswap uses hardcoded values of 4095 and 4096 throughout as page
stride and page size, which are only correct on systems with a 4K page
size. On architectures with larger pages (e.g., 64K on arm64 or ppc64),
these constants cause memory to be touched at sub-page granularity,
leading to inefficient access patterns and incorrect page count
calculations, which can cause test failures.
Replace all hardcoded 4095 and 4096 values with a global pagesize variable
initialized from sysconf(_SC_PAGESIZE) at startup, and remove the
redundant local sysconf() calls scattered across individual functions. No
functional change on 4K page size systems.
Link: https://lore.kernel.org/20260424040059.12940-6-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Yosry Ahmed <yosry@kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The cgroup utility code defines a local PAGE_SIZE macro hardcoded to 4096,
which is used primarily as a generic buffer size for reading cgroup and
proc files. This naming is misleading because the value has nothing to do
with the actual page size of the system. On architectures with larger
pages (e.g., 64K on arm64 or ppc64), the name suggests a relationship that
does not exist. Additionally, the name can shadow or conflict with
PAGE_SIZE definitions from system headers, leading to confusion or subtle
bugs.
To resolve this, rename the macro to BUF_SIZE to accurately reflect its
purpose as a general I/O buffer size.
Furthermore, test_memcontrol currently relies on this hardcoded 4K value
to stride through memory and trigger page faults. Update this logic to
use the actual system page size dynamically. This micro-optimizes the
memory faulting process by ensuring it iterates correctly and efficiently
based on the underlying architecture's true page size. (This part from
Waiman)
Link: https://lore.kernel.org/20260424040059.12940-5-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
test_zswapin compares memory.stat:zswpin (counted in pages) against a byte
threshold converted with PAGE_SIZE. In cgroup selftests, PAGE_SIZE is
hardcoded to 4096, which makes the conversion wrong on systems with non-4K
base pages (e.g. 64K).
As a result, the test requires too many pages to pass and fails spuriously
even when zswap is working.
Use sysconf(_SC_PAGESIZE) for the zswpin threshold conversion so the check
matches the actual system page size.
Link: https://lore.kernel.org/20260424040059.12940-4-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Reviewed-by: Yosry Ahmed <yosry@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
test_swapin_nozswap can hit OOM before reaching its assertions on some
setups. The test currently sets memory.max=8M and then allocates/reads
32M with memory.zswap.max=0, which may over-constrain reclaim and kill the
workload process.
Replace hardcoded sizes with PAGE_SIZE-based values:
- control_allocation_size = PAGE_SIZE * 512
- memory.max = control_allocation_size * 3 / 4
- minimum expected swap = control_allocation_size / 4
This keeps the test pressure model intact (allocate/read beyond memory.max
to force swap-in/out) while making it more robust across different
environments.
The test intent is unchanged: confirm that swapping occurs while zswap remains
unused when memory.zswap.max=0.
=== Error Logs ===
# ./test_zswap
TAP version 13
1..7
ok 1 test_zswap_usage
not ok 2 test_swapin_nozswap
...
# dmesg
[271641.879153] test_zswap invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), order=0, oom_score_adj=0
[271641.879168] CPU: 1 UID: 0 PID: 177372 Comm: test_zswap Kdump: loaded Not tainted 6.12.0-211.el10.ppc64le #1 VOLUNTARY
[271641.879171] Hardware name: IBM,9009-41A POWER9 (architected) 0x4e0202 0xf000005 of:IBM,FW940.02 (UL940_041) hv:phyp pSeries
[271641.879173] Call Trace:
[271641.879174] [c00000037540f730] [c00000000127ec44] dump_stack_lvl+0x88/0xc4 (unreliable)
[271641.879184] [c00000037540f760] [c0000000005cc594] dump_header+0x5c/0x1e4
[271641.879188] [c00000037540f7e0] [c0000000005cb464] oom_kill_process+0x324/0x3b0
[271641.879192] [c00000037540f860] [c0000000005cbe48] out_of_memory+0x118/0x420
[271641.879196] [c00000037540f8f0] [c00000000070d8ec] mem_cgroup_out_of_memory+0x18c/0x1b0
[271641.879200] [c00000037540f990] [c000000000713888] try_charge_memcg+0x598/0x890
[271641.879204] [c00000037540fa70] [c000000000713dbc] charge_memcg+0x5c/0x110
[271641.879207] [c00000037540faa0] [c0000000007159f8] __mem_cgroup_charge+0x48/0x120
[271641.879211] [c00000037540fae0] [c000000000641914] alloc_anon_folio+0x2b4/0x5a0
[271641.879215] [c00000037540fb60] [c000000000641d58] do_anonymous_page+0x158/0x6b0
[271641.879218] [c00000037540fbd0] [c000000000642f8c] __handle_mm_fault+0x4bc/0x910
[271641.879221] [c00000037540fcf0] [c000000000643500] handle_mm_fault+0x120/0x3c0
[271641.879224] [c00000037540fd40] [c00000000014bba0] ___do_page_fault+0x1c0/0x980
[271641.879228] [c00000037540fdf0] [c00000000014c44c] hash__do_page_fault+0x2c/0xc0
[271641.879232] [c00000037540fe20] [c0000000001565d8] do_hash_fault+0x128/0x1d0
[271641.879236] [c00000037540fe50] [c000000000008be0] data_access_common_virt+0x210/0x220
[271641.879548] Tasks state (memory values in pages):
...
[271641.879550] [ pid ] uid tgid total_vm rss rss_anon rss_file rss_shmem pgtables_bytes swapents oom_score_adj name
[271641.879555] [ 177372] 0 177372 571 0 0 0 0 51200 96 0 test_zswap
[271641.879562] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=/,mems_allowed=0,oom_memcg=/no_zswap_test,task_memcg=/no_zswap_test,task=test_zswap,pid=177372,uid=0
[271641.879578] Memory cgroup out of memory: Killed process 177372 (test_zswap) total-vm:36544kB, anon-rss:0kB, file-rss:0kB, shmem-rss:0kB, UID:0 pgtables:50kB oom_score_adj:0
Link: https://lore.kernel.org/20260424040059.12940-3-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Yosry Ahmed <yosry@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "selftests/cgroup: improve zswap tests robustness and support
large page sizes", v7.
This patchset aims to fix various spurious failures and improve the
overall robustness of the cgroup zswap selftests.
The primary motivation is to make the tests compatible with architectures
that use non-4K page sizes (such as 64K on ppc64le and arm64). Currently,
the tests rely heavily on hardcoded 4K page sizes and fixed memory limits.
On 64K page size systems, these hardcoded values lead to sub-page
granularity accesses, incorrect page count calculations, and insufficient
memory pressure to trigger zswap writeback, ultimately causing the tests
to fail.
Additionally, this series addresses OOM kills occurring in
test_swapin_nozswap by dynamically scaling memory limits, and prevents
spurious test failures when zswap is built into the kernel but globally
disabled.
This patch (of 8):
test_zswap currently only checks whether zswap is present by testing
/sys/module/zswap. This misses the runtime global state exposed in
/sys/module/zswap/parameters/enabled.
When zswap is built/loaded but globally disabled, the zswap cgroup
selftests run in an invalid environment and may fail spuriously.
Check the runtime enabled state before running the tests:
- skip if zswap is not configured,
- fail if the enabled knob cannot be read,
- skip if zswap is globally disabled.
Also print a hint in the skip message on how to enable zswap.
Link: https://lore.kernel.org/20260424040059.12940-1-li.wang@linux.dev
Link: https://lore.kernel.org/20260424040059.12940-2-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Yosry Ahmed <yosry@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.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: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When sibling CPU exclusion occurs, a partition's effective_xcpus may be
a subset of its user_xcpus. The partcmd_update path must use
effective_xcpus instead of user_xcpus when calculating CPUs to return
to or request from the parent.
Add two test cases to verify this behavior:
1) Narrowing cpuset.cpus to only the sibling-excluded CPUs should not
return CPUs to parent that the partition never actually owned.
2) Expanding cpuset.cpus after a sibling becomes a member should
correctly request the additional CPUs from parent.
Co-developed-by: Zhang Guopeng <zhangguopeng@kylinos.cn>
Signed-off-by: Zhang Guopeng <zhangguopeng@kylinos.cn>
Signed-off-by: Sun Shaojie <sunshaojie@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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test_hugetlb_memcg creates a child cgroup and then writes memory.max and
memory.swap.max. When the test is run standalone, the memory controller
may not be enabled in the test root cgroup's subtree_control.
In that case, the child cgroup is created without the memory control
files, and the test fails during setup before reaching the hugetlb memcg
accounting checks.
Skip the test when the memory controller is unavailable. Otherwise, enable
it in subtree_control before creating the test cgroup.
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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When cg_name_indexed() returns NULL partway through the child creation
loop, the code returned -1 without running cleanup_children and cleanup.
That left the `parent` pathname allocation unreleased and did not remove
child cgroup directories already created under the parent. Fix by jumping
to cleanup_children instead of returning.
When cg_create() fails, `child` (the pathname from cg_name_indexed())
was not freed before cleanup_children. Fix by freeing `child` before
branching to cleanup_children.
Fixes: 90631e1dea55 ("kselftests: cgroup: add perpcu memory accounting test")
Signed-off-by: Yu Miao <yumiao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The alloc_anon() function calls malloc() without checking for a NULL
return. If memory allocation fails, a NULL pointer dereference will
occur when accessing the buffer.
Add proper error handling to return -1 when malloc() fails in all
four alloc_anon variants:
- alloc_anon()
- alloc_anon_50M_check()
- alloc_anon_noexit()
- alloc_anon_50M_check_swap()
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Reviewed-by: Vishal Moola <vishal.moola@gmail.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Pull to receive dde2f938d02f ("cgroup/cpuset: move PF_EXITING check
before __GFP_HARDWALL in cpuset_current_node_allowed()") as a
dependency for an upcoming patch in the same function.
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
The debug message says "Expect ctime <= ptime" when the test actually
expects ctime > ptime (child's freeze time should exceed parent's,
which is zero). Fix the message to match the actual expectation.
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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In test_cpucg_nice, the forked child process incorrectly jumps to the
parent's cleanup label on cg_write failure. This causes the child to
attempt cg_destroy on cgroups the parent is still using, and then
return to main() to continue executing tests as if it were the parent.
Replace goto cleanup with exit(EXIT_FAILURE) in the child process.
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Add NULL checks after malloc() in three helper functions to prevent
NULL pointer dereference on memory allocation failure.
- cg_name()
- cg_name_indexed()
- cg_control()
These functions allocate memory with malloc() but previously called
snprintf() unconditionally, which would trigger undefined behavior
if allocation fails.
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Use string comparison (!=) instead of numeric comparison (-ne) for
cpuset values like "0-1".
For example:
$ [[ "0-1" != "2-3" ]] && echo "true" || echo "false"
true
$ [[ "0-1" -ne "2-3" ]] && echo "true" || echo "false"
false
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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cg_read_strcmp() allocated a buffer sized to strlen(expected) + 1,
then passed it to read_text() which calls read(fd, buf, size-1).
When comparing against an empty string (""), strlen("") = 0 gives a
1-byte buffer, and read() is asked to read 0 bytes. The file content
is never actually read, so strcmp("", buf) always returns 0 regardless
of the real content. This caused cg_test_proc_killed() to always
report the cgroup as empty immediately, making OOM tests pass without
verifying that processes were killed.
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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"OFFLINE_CPUS" is a literal string that is always non-empty. It should
be "$OFFLINE_CPUS" to check the variable's value instead.
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
Pull MM updates from Andrew Morton:
- "maple_tree: Replace big node with maple copy" (Liam Howlett)
Mainly prepararatory work for ongoing development but it does reduce
stack usage and is an improvement.
- "mm, swap: swap table phase III: remove swap_map" (Kairui Song)
Offers memory savings by removing the static swap_map. It also yields
some CPU savings and implements several cleanups.
- "mm: memfd_luo: preserve file seals" (Pratyush Yadav)
File seal preservation to LUO's memfd code
- "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan
Chen)
Additional userspace stats reportng to zswap
- "arch, mm: consolidate empty_zero_page" (Mike Rapoport)
Some cleanups for our handling of ZERO_PAGE() and zero_pfn
- "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu
Han)
A robustness improvement and some cleanups in the kmemleak code
- "Improve khugepaged scan logic" (Vernon Yang)
Improve khugepaged scan logic and reduce CPU consumption by
prioritizing scanning tasks that access memory frequently
- "Make KHO Stateless" (Jason Miu)
Simplify Kexec Handover by transitioning KHO from an xarray-based
metadata tracking system with serialization to a radix tree data
structure that can be passed directly to the next kernel
- "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas
Ballasi and Steven Rostedt)
Enhance vmscan's tracepointing
- "mm: arch/shstk: Common shadow stack mapping helper and
VM_NOHUGEPAGE" (Catalin Marinas)
Cleanup for the shadow stack code: remove per-arch code in favour of
a generic implementation
- "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin)
Fix a WARN() which can be emitted the KHO restores a vmalloc area
- "mm: Remove stray references to pagevec" (Tal Zussman)
Several cleanups, mainly udpating references to "struct pagevec",
which became folio_batch three years ago
- "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl
Shutsemau)
Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail
pages encode their relationship to the head page
- "mm/damon/core: improve DAMOS quota efficiency for core layer
filters" (SeongJae Park)
Improve two problematic behaviors of DAMOS that makes it less
efficient when core layer filters are used
- "mm/damon: strictly respect min_nr_regions" (SeongJae Park)
Improve DAMON usability by extending the treatment of the
min_nr_regions user-settable parameter
- "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka)
The proper fix for a previously hotfixed SMP=n issue. Code
simplifications and cleanups ensued
- "mm: cleanups around unmapping / zapping" (David Hildenbrand)
A bunch of cleanups around unmapping and zapping. Mostly
simplifications, code movements, documentation and renaming of
zapping functions
- "support batched checking of the young flag for MGLRU" (Baolin Wang)
Batched checking of the young flag for MGLRU. It's part cleanups; one
benchmark shows large performance benefits for arm64
- "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner)
memcg cleanup and robustness improvements
- "Allow order zero pages in page reporting" (Yuvraj Sakshith)
Enhance free page reporting - it is presently and undesirably order-0
pages when reporting free memory.
- "mm: vma flag tweaks" (Lorenzo Stoakes)
Cleanup work following from the recent conversion of the VMA flags to
a bitmap
- "mm/damon: add optional debugging-purpose sanity checks" (SeongJae
Park)
Add some more developer-facing debug checks into DAMON core
- "mm/damon: test and document power-of-2 min_region_sz requirement"
(SeongJae Park)
An additional DAMON kunit test and makes some adjustments to the
addr_unit parameter handling
- "mm/damon/core: make passed_sample_intervals comparisons
overflow-safe" (SeongJae Park)
Fix a hard-to-hit time overflow issue in DAMON core
- "mm/damon: improve/fixup/update ratio calculation, test and
documentation" (SeongJae Park)
A batch of misc/minor improvements and fixups for DAMON
- "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David
Hildenbrand)
Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code
movement was required.
- "zram: recompression cleanups and tweaks" (Sergey Senozhatsky)
A somewhat random mix of fixups, recompression cleanups and
improvements in the zram code
- "mm/damon: support multiple goal-based quota tuning algorithms"
(SeongJae Park)
Extend DAMOS quotas goal auto-tuning to support multiple tuning
algorithms that users can select
- "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao)
Fix the khugpaged sysfs handling so we no longer spam the logs with
reams of junk when starting/stopping khugepaged
- "mm: improve map count checks" (Lorenzo Stoakes)
Provide some cleanups and slight fixes in the mremap, mmap and vma
code
- "mm/damon: support addr_unit on default monitoring targets for
modules" (SeongJae Park)
Extend the use of DAMON core's addr_unit tunable
- "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache)
Cleanups to khugepaged and is a base for Nico's planned khugepaged
mTHP support
- "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand)
Code movement and cleanups in the memhotplug and sparsemem code
- "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup
CONFIG_MIGRATION" (David Hildenbrand)
Rationalize some memhotplug Kconfig support
- "change young flag check functions to return bool" (Baolin Wang)
Cleanups to change all young flag check functions to return bool
- "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh
Law and SeongJae Park)
Fix a few potential DAMON bugs
- "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo
Stoakes)
Convert a lot of the existing use of the legacy vm_flags_t data type
to the new vma_flags_t type which replaces it. Mainly in the vma
code.
- "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes)
Expand the mmap_prepare functionality, which is intended to replace
the deprecated f_op->mmap hook which has been the source of bugs and
security issues for some time. Cleanups, documentation, extension of
mmap_prepare into filesystem drivers
- "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes)
Simplify and clean up zap_huge_pmd(). Additional cleanups around
vm_normal_folio_pmd() and the softleaf functionality are performed.
* tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm: fix deferred split queue races during migration
mm/khugepaged: fix issue with tracking lock
mm/huge_memory: add and use has_deposited_pgtable()
mm/huge_memory: add and use normal_or_softleaf_folio_pmd()
mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio()
mm/huge_memory: separate out the folio part of zap_huge_pmd()
mm/huge_memory: use mm instead of tlb->mm
mm/huge_memory: remove unnecessary sanity checks
mm/huge_memory: deduplicate zap deposited table call
mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE()
mm/huge_memory: add a common exit path to zap_huge_pmd()
mm/huge_memory: handle buggy PMD entry in zap_huge_pmd()
mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc
mm/huge: avoid big else branch in zap_huge_pmd()
mm/huge_memory: simplify vma_is_specal_huge()
mm: on remap assert that input range within the proposed VMA
mm: add mmap_action_map_kernel_pages[_full]()
uio: replace deprecated mmap hook with mmap_prepare in uio_info
drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare
mm: allow handling of stacked mmap_prepare hooks in more drivers
...
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Pull driver core updates from Danilo Krummrich:
"debugfs:
- Fix NULL pointer dereference in debugfs_create_str()
- Fix misplaced EXPORT_SYMBOL_GPL for debugfs_create_str()
- Fix soundwire debugfs NULL pointer dereference from uninitialized
firmware_file
device property:
- Make fwnode flags modifications thread safe; widen the field to
unsigned long and use set_bit() / clear_bit() based accessors
- Document how to check for the property presence
devres:
- Separate struct devres_node from its "subclasses" (struct devres,
struct devres_group); give struct devres_node its own release and
free callbacks for per-type dispatch
- Introduce struct devres_action for devres actions, avoiding the
ARCH_DMA_MINALIGN alignment overhead of struct devres
- Export struct devres_node and its init/add/remove/dbginfo
primitives for use by Rust Devres<T>
- Fix missing node debug info in devm_krealloc()
- Use guard(spinlock_irqsave) where applicable; consolidate unlock
paths in devres_release_group()
driver_override:
- Convert PCI, WMI, vdpa, s390/cio, s390/ap, and fsl-mc to the
generic driver_override infrastructure, replacing per-bus
driver_override strings, sysfs attributes, and match logic; fixes a
potential UAF from unsynchronized access to driver_override in bus
match() callbacks
- Simplify __device_set_driver_override() logic
kernfs:
- Send IN_DELETE_SELF and IN_IGNORED inotify events on kernfs file
and directory removal
- Add corresponding selftests for memcg
platform:
- Allow attaching software nodes when creating platform devices via a
new 'swnode' field in struct platform_device_info
- Add kerneldoc for struct platform_device_info
software node:
- Move software node initialization from postcore_initcall() to
driver_init(), making it available early in the boot process
- Move kernel_kobj initialization (ksysfs_init) earlier to support
the above
- Remove software_node_exit(); dead code in a built-in unit
SoC:
- Introduce of_machine_read_compatible() and of_machine_read_model()
OF helpers and export soc_attr_read_machine() to replace direct
accesses to of_root from SoC drivers; also enables
CONFIG_COMPILE_TEST coverage for these drivers
sysfs:
- Constify attribute group array pointers to
'const struct attribute_group *const *' in sysfs functions,
device_add_groups() / device_remove_groups(), and struct class
Rust:
- Devres:
- Embed struct devres_node directly in Devres<T> instead of going
through devm_add_action(), avoiding the extra allocation and the
unnecessary ARCH_DMA_MINALIGN alignment
- I/O:
- Turn IoCapable from a marker trait into a functional trait
carrying the raw I/O accessor implementation (io_read /
io_write), providing working defaults for the per-type Io
methods
- Add RelaxedMmio wrapper type, making relaxed accessors usable in
code generic over the Io trait
- Remove overloaded per-type Io methods and per-backend macros
from Mmio and PCI ConfigSpace
- I/O (Register):
- Add IoLoc trait and generic read/write/update methods to the Io
trait, making I/O operations parameterizable by typed locations
- Add register! macro for defining hardware register types with
typed bitfield accessors backed by Bounded values; supports
direct, relative, and array register addressing
- Add write_reg() / try_write_reg() and LocatedRegister trait
- Update PCI sample driver to demonstrate the register! macro
Example:
```
register! {
/// UART control register.
CTRL(u32) @ 0x18 {
/// Receiver enable.
19:19 rx_enable => bool;
/// Parity configuration.
14:13 parity ?=> Parity;
}
/// FIFO watermark and counter register.
WATER(u32) @ 0x2c {
/// Number of datawords in the receive FIFO.
26:24 rx_count;
/// RX interrupt threshold.
17:16 rx_water;
}
}
impl WATER {
fn rx_above_watermark(&self) -> bool {
self.rx_count() > self.rx_water()
}
}
fn init(bar: &pci::Bar<BAR0_SIZE>) {
let water = WATER::zeroed()
.with_const_rx_water::<1>(); // > 3 would not compile
bar.write_reg(water);
let ctrl = CTRL::zeroed()
.with_parity(Parity::Even)
.with_rx_enable(true);
bar.write_reg(ctrl);
}
fn handle_rx(bar: &pci::Bar<BAR0_SIZE>) {
if bar.read(WATER).rx_above_watermark() {
// drain the FIFO
}
}
fn set_parity(bar: &pci::Bar<BAR0_SIZE>, parity: Parity) {
bar.update(CTRL, |r| r.with_parity(parity));
}
```
- IRQ:
- Move 'static bounds from where clauses to trait declarations for
IRQ handler traits
- Misc:
- Enable the generic_arg_infer Rust feature
- Extend Bounded with shift operations, single-bit bool
conversion, and const get()
Misc:
- Make deferred_probe_timeout default a Kconfig option
- Drop auxiliary_dev_pm_ops; the PM core falls back to driver PM
callbacks when no bus type PM ops are set
- Add conditional guard support for device_lock()
- Add ksysfs.c to the DRIVER CORE MAINTAINERS entry
- Fix kernel-doc warnings in base.h
- Fix stale reference to memory_block_add_nid() in documentation"
* tag 'driver-core-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (67 commits)
bus: fsl-mc: use generic driver_override infrastructure
s390/ap: use generic driver_override infrastructure
s390/cio: use generic driver_override infrastructure
vdpa: use generic driver_override infrastructure
platform/wmi: use generic driver_override infrastructure
PCI: use generic driver_override infrastructure
driver core: make software nodes available earlier
software node: remove software_node_exit()
kernel: ksysfs: initialize kernel_kobj earlier
MAINTAINERS: add ksysfs.c to the DRIVER CORE entry
drivers/base/memory: fix stale reference to memory_block_add_nid()
device property: Document how to check for the property presence
soundwire: debugfs: initialize firmware_file to empty string
debugfs: fix placement of EXPORT_SYMBOL_GPL for debugfs_create_str()
debugfs: check for NULL pointer in debugfs_create_str()
driver core: Make deferred_probe_timeout default a Kconfig option
driver core: simplify __device_set_driver_override() clearing logic
driver core: auxiliary bus: Drop auxiliary_dev_pm_ops
device property: Make modifications of fwnode "flags" thread safe
rust: devres: embed struct devres_node directly
...
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The test_memcg_sock test in memcontrol.c sets up an IPv6 socket and send
data over it to consume memory and verify that memory.stat.sock and
memory.current values are close.
On systems where IPv6 isn't enabled or not configured to support
SOCK_STREAM, the test_memcg_sock test always fails. When the socket()
call fails, there is no way we can test the memory consumption and verify
the above claim. I believe it is better to just skip the test in this
case instead of reporting a test failure hinting that there may be
something wrong with the memcg code.
Link: https://lkml.kernel.org/r/20260311200526.885899-1-longman@redhat.com
Fixes: 5f8f019380b8 ("selftests: cgroup/memcontrol: add basic test for socket accounting")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add test_zswap_incompressible() to verify that the zswap_incomp memcg stat
correctly tracks incompressible pages.
The test allocates memory filled with random data from /dev/urandom, which
cannot be effectively compressed by zswap. When this data is swapped out
to zswap, it should be stored as-is and tracked by the zswap_incomp
counter.
The test verifies that:
1. Pages are swapped out to zswap (zswpout increases)
2. Incompressible pages are tracked (zswap_incomp increases)
test:
dd if=/dev/zero of=/swapfile bs=1M count=2048
chmod 600 /swapfile
mkswap /swapfile
swapon /swapfile
echo Y > /sys/module/zswap/parameters/enabled
./test_zswap
TAP version 13
1..8
ok 1 test_zswap_usage
ok 2 test_swapin_nozswap
ok 3 test_zswapin
ok 4 test_zswap_writeback_enabled
ok 5 test_zswap_writeback_disabled
ok 6 test_no_kmem_bypass
ok 7 test_no_invasive_cgroup_shrink
ok 8 test_zswap_incompressible
Totals: pass:8 fail:0 xfail:0 xpass:0 skip:0 error:0
Link: https://lkml.kernel.org/r/20260213071827.5688-3-jiayuan.chen@linux.dev
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: 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: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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test_cgcore_populated (test_core) and test_cgkill_{simple,tree,forkbomb}
(test_kill) check cgroup.events "populated 0" immediately after reaping
child tasks with waitpid(). This used to work because cgroup_task_exit() in
do_exit() unlinked tasks from css_sets before exit_notify() woke up
waitpid().
d245698d727a ("cgroup: Defer task cgroup unlink until after the task is done
switching out") moved the unlink to cgroup_task_dead() in
finish_task_switch(), which runs after exit_notify(). The populated counter
is now decremented after the parent's waitpid() can return, so there is no
longer a synchronous ordering guarantee. On PREEMPT_RT, where
cgroup_task_dead() is further deferred through lazy irq_work, the race
window is even larger.
The synchronous populated transition was never part of the cgroup interface
contract - it was an implementation artifact. Use cg_read_strcmp_wait() which
retries for up to 1 second, matching what these tests actually need to
verify: that the cgroup eventually becomes unpopulated after all tasks exit.
Fixes: d245698d727a ("cgroup: Defer task cgroup unlink until after the task is done switching out")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Christian Brauner <brauner@kernel.org>
Cc: cgroups@vger.kernel.org
|
|
Add two new tests that verify inotify events are sent when memcg files
or directories are removed with rmdir.
Signed-off-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: syzbot@syzkaller.appspotmail.com
Link: https://patch.msgid.link/20260225223404.783173-4-tjmercier@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
The cpuset_handle_hotplug() may need to invoke housekeeping_update(),
for instance, when an isolated partition is invalidated because its
last active CPU has been put offline.
As we are going to enable dynamic update to the nozh_full housekeeping
cpumask (HK_TYPE_KERNEL_NOISE) soon with the help of CPU hotplug,
allowing the CPU hotplug path to call into housekeeping_update() directly
from update_isolation_cpumasks() will likely cause deadlock. So we
have to defer any call to housekeeping_update() after the CPU hotplug
operation has finished. This is now done via the workqueue where
the update_hk_sched_domains() function will be invoked via the
hk_sd_workfn().
An concurrent cpuset control file write may have executed the required
update_hk_sched_domains() function before the work function is called. So
the work function call may become a no-op when it is invoked.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
The "S+" command is used in the test matrix to enable the cpuset
controller. However this can be done automatically and we never use the
"S-" command to disable cpuset controller. Simplify the test matrix and
reduce clutter by removing the command and doing that automatically.
There is no functional change to the test cases.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
As stated in commit 1c09b195d37f ("cpuset: fix a regression in validating
config change"), it is not allowed to clear masks of a cpuset if
there're tasks in it. This is specific to v1 since empty "cpuset.cpus"
or "cpuset.mems" will cause the v2 cpuset to inherit the effective CPUs
or memory nodes from its parent. So it is OK to have empty cpus or mems
even if there are tasks in the cpuset.
Move this empty cpus/mems check in validate_change() to
cpuset1_validate_change() to allow more flexibility in setting
cpus or mems in v2. cpuset_is_populated() needs to be moved into
cpuset-internal.h as it is needed by the empty cpus/mems checking code.
Also add a test case to test_cpuset_prs.sh to verify that.
Reported-by: Chen Ridong <chenridong@huaweicloud.com>
Closes: https://lore.kernel.org/lkml/7a3ec392-2e86-4693-aa9f-1e668a668b9c@huaweicloud.com/
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Currently, when setting a cpuset's cpuset.cpus to a value that conflicts
with the cpuset.cpus/cpuset.cpus.exclusive of a sibling partition,
the sibling's partition state becomes invalid. This is overly harsh and
is probably not necessary.
The cpuset.cpus.exclusive control file, if set, will override the
cpuset.cpus of the same cpuset when creating a cpuset partition.
So cpuset.cpus has less priority than cpuset.cpus.exclusive in setting up
a partition. However, it cannot override a conflicting cpuset.cpus file
in a sibling cpuset and the partition creation process will fail. This
is inconsistent. That will also make using cpuset.cpus.exclusive less
valuable as a tool to set up cpuset partitions as the users have to
check if such a cpuset.cpus conflict exists or not.
Fix these problems by making sure that once a cpuset.cpus.exclusive
is set without failure, it will always be allowed to form a valid
partition as long as at least one CPU can be granted from its parent
irrespective of the state of the siblings' cpuset.cpus values. Of
course, setting cpuset.cpus.exclusive will fail if it conflicts with
the cpuset.cpus.exclusive or the cpuset.cpus.exclusive.effective value
of a sibling.
Partition can still be created by setting only cpuset.cpus without
setting cpuset.cpus.exclusive. However, any conflicting CPUs in sibling's
cpuset.cpus.exclusive.effective and cpuset.cpus.exclusive values will
be removed from its cpuset.cpus.exclusive.effective as long as there
is still one or more CPUs left and can be granted from its parent. This
CPU stripping is currently done in rm_siblings_excl_cpus().
The new code will now try its best to enable the creation of new
partitions with only cpuset.cpus set without invalidating existing ones.
However it is not guaranteed that all the CPUs requested in cpuset.cpus
will be used in the new partition even when all these CPUs can be
granted from the parent.
This is similar to the fact that cpuset.cpus.effective may not be
able to include all the CPUs requested in cpuset.cpus. In this case,
the parent may not able to grant all the exclusive CPUs requested in
cpuset.cpus to cpuset.cpus.exclusive.effective if some of them have
already been granted to other partitions earlier.
With the creation of multiple sibling partitions by setting
only cpuset.cpus, this does have the side effect that their exact
cpuset.cpus.exclusive.effective settings will depend on the order of
partition creation if there are conflicts. Due to the exclusive nature
of the CPUs in a partition, it is not easy to make it fair other than
the old behavior of invalidating all the conflicting partitions.
For example,
# echo "0-2" > A1/cpuset.cpus
# echo "root" > A1/cpuset.cpus.partition
# cat A1/cpuset.cpus.partition
root
# cat A1/cpuset.cpus.exclusive.effective
0-2
# echo "2-4" > B1/cpuset.cpus
# echo "root" > B1/cpuset.cpus.partition
# cat B1/cpuset.cpus.partition
root
# cat B1/cpuset.cpus.exclusive.effective
3-4
# cat B1/cpuset.cpus.effective
3-4
For users who want to be sure that they can get most of the CPUs they
want, cpuset.cpus.exclusive should be used instead if they can set
it successfully without failure. Setting cpuset.cpus.exclusive will
guarantee that sibling conflicts from then onward is no longer possible.
To make this change, we have to separate out the is_cpu_exclusive()
check in cpus_excl_conflict() into a cgroup v1 only
cpuset1_cpus_excl_conflict() helper. The cpus_allowed_validate_change()
helper is now no longer needed and can be removed.
Some existing tests in test_cpuset_prs.sh are updated and new ones are
added to reflect the new behavior. The cgroup-v2.rst doc file is also
updated the clarify what exclusive CPUs will be used when a partition
is created.
Reported-by: Sun Shaojie <sunshaojie@kylinos.cn>
Closes: https://lore.kernel.org/lkml/20251117015708.977585-1-sunshaojie@kylinos.cn/
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Replace the manual sleep-and-retry logic in test_kmem_dead_cgroups()
with the new helper `cg_read_key_long_poll()`. This change improves
the robustness of the test by polling the "nr_dying_descendants"
counter in `cgroup.stat` until it reaches 0 or the timeout is exceeded.
Additionally, increase the retry timeout to 8 seconds (from 5 seconds)
based on testing results:
- With 5-second timeout: 4/20 runs passed.
- With 8-second timeout: 20/20 runs passed.
The 8 second timeout is based on stress testing of test_kmem_dead_cgroups()
under load: 5 seconds was occasionally not enough for reclaim of dying
descendants to complete, whereas 8 seconds consistently covered the observed
latencies. This value is intended as a generous upper bound for the
asynchronous reclaim and is not tied to any specific kernel constant, so it
can be adjusted in the future if reclaim behavior changes.
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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test_memcg_sock() currently requires that memory.stat's "sock " counter
is exactly zero immediately after the TCP server exits. On a busy system
this assumption is too strict:
- Socket memory may be freed with a small delay (e.g. RCU callbacks).
- memcg statistics are updated asynchronously via the rstat flushing
worker, so the "sock " value in memory.stat can stay non-zero for a
short period of time even after all socket memory has been uncharged.
As a result, test_memcg_sock() can intermittently fail even though socket
memory accounting is working correctly.
Make the test more robust by polling memory.stat for the "sock "
counter and allowing it some time to drop to zero instead of checking
it only once. The timeout is set to 3 seconds to cover the periodic
rstat flush interval (FLUSH_TIME = 2*HZ by default) plus some
scheduling slack. If the counter does not become zero within the
timeout, the test still fails as before.
On my test system, running test_memcontrol 50 times produced:
- Before this patch: 6/50 runs passed.
- After this patch: 50/50 runs passed.
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Suggested-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Introduce a new helper function `cg_read_key_long_poll()` in
cgroup_util.h. This function polls the specified key in a cgroup file
until it matches the expected value or the retry limit is reached,
with configurable wait intervals between retries.
This helper is particularly useful for handling asynchronously updated
cgroup statistics (e.g., memory.stat), where immediate reads may
observe stale values, especially on busy systems. It allows tests and
other utilities to handle such cases more flexibly.
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Pull non-MM updates from Andrew Morton:
- "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
fixes a build issue and does some cleanup in ib/sys_info.c
- "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
enhances the 64-bit math code on behalf of a PWM driver and beefs up
the test module for these library functions
- "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
makes BPF symbol names, sizes, and line numbers available to the GDB
debugger
- "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
adds a sysctl which can be used to cause additional info dumping when
the hung-task and lockup detectors fire
- "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
adds a general base64 encoder/decoder to lib/ and migrates several
users away from their private implementations
- "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
makes TCP a little faster
- "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
reworks the KEXEC Handover interfaces in preparation for Live Update
Orchestrator (LUO), and possibly for other future clients
- "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
increases the flexibility of KEXEC Handover. Also preparation for LUO
- "Live Update Orchestrator" (Pasha Tatashin)
is a major new feature targeted at cloud environments. Quoting the
cover letter:
This series introduces the Live Update Orchestrator, a kernel
subsystem designed to facilitate live kernel updates using a
kexec-based reboot. This capability is critical for cloud
environments, allowing hypervisors to be updated with minimal
downtime for running virtual machines. LUO achieves this by
preserving the state of selected resources, such as memory,
devices and their dependencies, across the kernel transition.
As a key feature, this series includes support for preserving
memfd file descriptors, which allows critical in-memory data, such
as guest RAM or any other large memory region, to be maintained in
RAM across the kexec reboot.
Mike Rappaport merits a mention here, for his extensive review and
testing work.
- "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
moves the kexec and kdump sysfs entries from /sys/kernel/ to
/sys/kernel/kexec/ and adds back-compatibility symlinks which can
hopefully be removed one day
- "kho: fixes for vmalloc restoration" (Mike Rapoport)
fixes a BUG which was being hit during KHO restoration of vmalloc()
regions
* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
calibrate: update header inclusion
Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
vmcoreinfo: track and log recoverable hardware errors
kho: fix restoring of contiguous ranges of order-0 pages
kho: kho_restore_vmalloc: fix initialization of pages array
MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
init: replace simple_strtoul with kstrtoul to improve lpj_setup
KHO: fix boot failure due to kmemleak access to non-PRESENT pages
Documentation/ABI: new kexec and kdump sysfs interface
Documentation/ABI: mark old kexec sysfs deprecated
kexec: move sysfs entries to /sys/kernel/kexec
test_kho: always print restore status
kho: free chunks using free_page() instead of kfree()
selftests/liveupdate: add kexec test for multiple and empty sessions
selftests/liveupdate: add simple kexec-based selftest for LUO
selftests/liveupdate: add userspace API selftests
docs: add documentation for memfd preservation via LUO
mm: memfd_luo: allow preserving memfd
liveupdate: luo_file: add private argument to store runtime state
mm: shmem: export some functions to internal.h
...
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Linus Torvalds
Wilson Felipe Pereira
Shaojie Sun
Rui Qi
Waiman Long
Jian Guo
Michal Koutný
Song Hu
Joe Simmons-Talbott
Li Wang
Guopeng Zhang
Yu Miao
Hongfu Li
Tejun Heo
Tao Cui
Jiayuan Chen
T.J. Mercier