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https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git
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The zswap_writeback_enabled test fails when a write to memory.reclaim
returns -EAGAIN, which means less than the requested amount was reclaimed.
attempt_writeback() propagates the -EAGAIN to the caller, and the test
case is marked as failed even when zswap writeback did happen.
This heavily depends on the performance of the backing swap device.
Reclaim does not wait for writeback (on cgroup v2), does not count pages
that are under writeback as reclaimed, and memory.reclaim gives up after
MAX_RECLAIM_RETRIES passes without making progress. On a slow device
where reclaim does not make any progress before writeback completes, a
write to memory.reclaim fails.
On a VM with zswap enabled, where IO delay was injected via dm-delay, the
success rate of the zswap writeback test drops dramatically once the delay
reaches 11 ms: 7% failures at 10 ms and 79% failures at 11 ms, n = 100.
When zswap writeback is enabled, ignore -EAGAIN from memory.reclaim and
determine pass/fail based on the zswpwb counter because that is what
zswap_writeback_enabled actually wants to test.
With this change, the test reliably passes even on a slow swap device
(tested up to 1000 ms delay). This makes the test resilient against the
performance of the swap device.
Link: https://lore.kernel.org/20260914-test-zswap-wb-ignore-eagain-v1-1-6fb715c22cd8@kernel.org
Fixes: 158863e5d7cc ("selftests: cgroup: add tests to verify the zswap writeback path")
Signed-off-by: Harry Yoo (Meta) <harry@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Assisted-by: LLM
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Usama Arif <usamaarif642@gmail.com>
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test_no_kmem_bypass
In test_no_kmem_bypass(), delta (stored_pages * page_size - zswapped) is
checked against stored_pages * page_size / 4 to verify that the pages
pushed to zswap belong to the test memory cgroup.
Due to slight stat update timing differences, delta can evaluate to a
small negative number (e.g. -5MB out of 1GB). Because delta is declared
as a signed int and stored_pages is an unsigned size_t, C's usual
arithmetic conversions implicitly promote a negative delta to a large
unsigned 64-bit integer, causing `delta < stored_pages * page_size / 4` to
falsely evaluate to 0 and fail the test.
Fix this by declaring zswapped and delta as signed long long and comparing
against a signed threshold, ensuring negative deltas correctly evaluate to
true.
Link: https://lore.kernel.org/20260828033741.2184560-3-wfelipe@google.com
Fixes: a549f9f31561a ("selftests: cgroup: add test_zswap with no kmem bypass test")
Signed-off-by: Wilson Felipe Pereira <wfelipe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Koutný <mkoutny@suse.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
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test_zswap_writeback
Patch series "selftests/cgroup: fixes for test_zswap on single core VM",
v4.
This series fixes two test failures in test_zswap observed when running on
a single-core VM (-smp 1) with 4GB of RAM.
Patch 1 addresses a race condition in test_zswap_writeback() where
waitpid() returns before the exiting child process is switched away by the
kernel, causing an immediate write of "+memory" to cgroup.subtree_control
to fail with -EBUSY. We fix this by waiting for cgroup.events to report
"populated 0".
Patch 2 fixes an implicit unsigned conversion bug in test_no_kmem_bypass()
where small negative timing differences between debugfs stored_pages and
cgroup zswapped bytes caused the comparison to falsely fail due to
unsigned promotion.
This patch (of 2):
When running test_zswap on a single-core VM (-smp 1) with 4GB of RAM,
test_zswap_writeback intermittently fails on the initial run after boot.
In test_zswap_writeback(), after waitpid() reaps the child process created
by test_zswap_writeback_one(), writing "+memory" to cgroup.subtree_control
can fail with -EBUSY. Under cgroup v2, enabling domain subtree
controllers is forbidden while any tasks remain in cgroup.procs.
When a child process exits, exit_notify() wakes the parent process,
allowing waitpid() to return immediately. However, the cgroup populated
task count (nr_populated_csets) is only decremented when the exiting task
is switched away via finish_task_switch() -> cgroup_task_dead(). On
single-core systems, the parent runs before the dead child has been
switched out, causing "+memory" to fail with -EBUSY if written immediately
after waitpid() returns.
Fix this by waiting for cgroup.events to report "populated 0\n" via
cg_read_strcmp_wait() before enabling subtree control.
Link: https://lore.kernel.org/20260828033741.2184560-1-wfelipe@google.com
Link: https://lore.kernel.org/20260828033741.2184560-2-wfelipe@google.com
Signed-off-by: Wilson Felipe Pereira <wfelipe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Koutný <mkoutny@suse.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
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with_stress.sh invokes the requested command through unquoted $*. This
subjects the arguments to word splitting and pathname expansion:
arguments containing whitespace are split, empty arguments disappear,
and literal wildcard characters can expand to filenames.
Invoke the command through "$@" so that the command name and each
argument are passed as supplied by the caller.
Assisted-by: LLM
Signed-off-by: Ren Tamura <ren.tamura.oss@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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test_cpu uses cg_read_strstr() to check for "cpu" in the root cgroup's
cgroup.subtree_control. The substring also matches "cpuset", so a
hierarchy with only cpuset enabled skips writing "+cpu" during setup.
The tests then run without the required controller enabled and report
failures. When cpu is unavailable in that hierarchy, the suite also
reports failures instead of skipping.
Always write "+cpu" during setup and skip if the write fails. Enabling a
controller that is already enabled is a no-op, so a separate presence
check is unnecessary. This requires write access to
cgroup.subtree_control even when cpu is already enabled.
Assisted-by: LLM
Signed-off-by: Ren Tamura <ren.tamura.oss@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The cgroup selftests lack a settings file, causing the kselftest runner
to apply its default 45s timeout. The test_cpu binary now exceeds this
limit, resulting in timeout failures that prevent the final test cases
from reporting results:
not ok 2 selftests: cgroup: test_cpu # TIMEOUT 45 seconds
Test execution times:
|Test | Duration |
|----------------------|-------------------- |
|cpu.weight (×4) | ~10s each |
|test_cpucg_stats | 2s CPU time |
|test_cpucg_nice | 2s CPU time |
|test_cpucg_max | 1000/HZ seconds |
|test_cpucg_max_nested | 1000/HZ seconds |
Total runtime: ~46s at HZ=1000, ~64s at HZ=100
When executed independently, all nine test cases complete
successfully (46.2s on a ppc64le HZ=1000 guest).
Introduce a settings file that increases the timeout to 120 seconds,
providing sufficient margin above the HZ=100 worst-case scenario.
Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
- A cpuset partition could claim CPUs an ancestor partition already
held exclusively. Restore the rejection an earlier change had turned
into a warning.
* tag 'cgroup-for-7.3-rc4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict
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subpartitions_cpus conflict
When a remote partition is created underneath an existing local partition
via a non-partition (PRS_MEMBER) intermediate cgroup, update_prstate() sees
parent->partition_root_state == PRS_MEMBER and calls
remote_partition_enable().
Commit 86888c7bd117 ("cgroup/cpuset: Add warnings to catch inconsistency
in exclusive CPUs") replaced the cpumask_intersects(tmp->new_cpus,
subpartitions_cpus) error check in remote_partition_enable() with
WARN_ON_ONCE(). As a result, remote_partition_enable() emits a warning
and proceeds to enable the remote partition on CPUs that are already
owned by the ancestor local partition in subpartitions_cpus.
This can be reproduced on Linux 7.3.0-rc3 with:
mkdir -p /tmp/cg1
mount -t cgroup2 none /tmp/cg1
echo "+cpuset" > /tmp/cg1/cgroup.subtree_control
mkdir /tmp/cg1/A
echo 1 > /tmp/cg1/A/cpuset.cpus
echo 1 > /tmp/cg1/A/cpuset.cpus.exclusive
echo root > /tmp/cg1/A/cpuset.cpus.partition
echo "+cpuset" > /tmp/cg1/A/cgroup.subtree_control
mkdir /tmp/cg1/A/B
echo 1 > /tmp/cg1/A/B/cpuset.cpus
echo 1 > /tmp/cg1/A/B/cpuset.cpus.exclusive
echo "+cpuset" > /tmp/cg1/A/B/cgroup.subtree_control
mkdir /tmp/cg1/A/B/D
echo 1 > /tmp/cg1/A/B/D/cpuset.cpus
echo 1 > /tmp/cg1/A/B/D/cpuset.cpus.exclusive
echo root > /tmp/cg1/A/B/D/cpuset.cpus.partition
which triggers:
WARNING: kernel/cgroup/cpuset.c:1594 at remote_partition_enable+0x1c1/0x300
and leaves both /tmp/cg1/A and /tmp/cg1/A/B/D as active root partitions
claiming exclusive CPU 1.
Fix this by returning PERR_NOCPUS when tmp->new_cpus intersects
subpartitions_cpus in remote_partition_enable(), matching the error code
used by remote_cpus_update() for the same subpartitions_cpus conflict, and
add a regression test case to
tools/testing/selftests/cgroup/test_cpuset_prs.sh.
Tested in QEMU on Linux 7.3.0-rc3 using the reproducer above and
tools/testing/selftests/cgroup/test_cpuset_prs.sh.
Fixes: 86888c7bd117 ("cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs")
Suggested-by: Guopeng Zhang <guopeng.zhang@linux.dev>
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- With local event accounting, a fork rejected by the pids controller
updated pids.events without notifying its pollers
- A cgroup selftest failed to compile with fortification enabled
because an O_TMPFILE open lacked its mode argument
* tag 'cgroup-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/pids: Restore pids.events notifications in local mode
selftests: cgroup: give the O_TMPFILE open in get_temp_fd() a mode
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cg_find_root() parses /proc/self/mounts with strtok() and assumes that
every field group it walks over is a complete "device mountpoint type
options freq passno" tuple. That only holds while the buffer is big
enough for the whole file: if the buffer is too small, the last tuple is
cut short, strtok() returns NULL for the missing fields, and the
strcmp(type, ...) and strstr(options, ...) calls that follow dereference
it.
The current buffer is 10 * BUF_SIZE, so reaching this needs a mount table
over 40K, but the crash is easy to hit in a sandbox: with BUF_SIZE
overridden to 6, which leaves a 60-byte buffer, cg_find_unified_root()
segfaults instead of failing.
Stop parsing as soon as a field is missing. Nothing follows a truncated
entry, so there is nothing to parse after it either.
Signed-off-by: Shaojie Sun <sunshaojie@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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read_text() issues a single read(2) and returns whatever it got, so a
caller that asks for a whole file silently gets a prefix of it instead.
For a seq_file larger than one page it never gets more than that prefix:
seq_read_iter() copies out at most one internal PAGE_SIZE buffer per call
and leaves the rest for the next read(2), no matter how much room the
caller's buffer has.
/proc/self/mounts is one of those files, so cg_find_root() only ever sees
the first 4K of the mount table. On a machine with ~80 mounts the cgroup2
entry already sits past that limit: the file is 7177 bytes, the single
read(2) into the 40K buffer in cg_find_root() returns 4035 bytes, and the
cgroup2 line starts at offset 4953. cg_find_root() then fails, and every
test that calls cg_find_unified_root() -- test_core, test_cpu, test_cpuset,
test_freezer, test_hugetlb_memcg, test_kill, test_kmem, test_memcontrol,
test_pids and test_zswap -- exits with SKIP "cgroup v2 isn't mounted"
without running a single test.
proc_mount_contains() searches only that same prefix, so a mount option
listed later in /proc/mounts is reported as absent, which is what the
probes in test_memcontrol and test_hugetlb_memcg are based on.
Read until the buffer is full or EOF instead. A partial read is still
possible when max_len is too small, so callers that deliberately read a
prefix, such as cg_read_strcmp(), keep working.
Signed-off-by: Shaojie Sun <sunshaojie@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The test_no_invasive_cgroup_shrink selftest checks that when a cgroup has
zswapped out more memory than memory.zswap.max, it does not trigger
writeback for other cgroups. To do this, it compares the writeback count
in a control cgroup and makes sure that it is 0, and then checks the
writeback count in an aggressor cgroup who does expect to see writeback.
However, when the zswap shrinker is enabled, the victim cgroup can see
legitimate writebacks not triggered by the aggressor. In some Meta CI
tests, we have seen this failure mode happen.
Instead of checking that the victim cgroup has 0 writeback, compare the
writeback values before and after the aggressor runs and check that the
victim cgroup did not perform any additional writeback. Note that this
can still lead to probabilistic failures if writebacks take longer than
5 seconds, but this should fix the systematic failure case and make
"not ok test_no_invasive_cgroup_shrink" less likely.
Link: https://lore.kernel.org/20260902194521.3652178-1-joshua.hahnjy@gmail.com
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Krush Chavan <krushchavan@outlook.com>
Suggested-by: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>
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O_TMPFILE, like O_CREAT, needs the third argument. Without it glibc
refuses the call at compile time as soon as fortification is on:
In function 'open',
inlined from 'get_temp_fd' at test_memcontrol.c:33:9:
/usr/include/bits/fcntl2.h:52:11: error: call to '__open_missing_mode'
declared with attribute error: open with O_CREAT or O_TMPFILE in
second argument needs 3 arguments
The fortify checks take effect only once the compiler optimises, and
cgroup/Makefile builds with "-Wall -pthread" alone, so this goes
unnoticed in a plain build. Building the tests with the flags
distributions commonly use, -O2 -D_FORTIFY_SOURCE=3, loses
test_memcontrol entirely.
Fixes: 84092dbcf901 ("selftests: cgroup: add memory controller self-tests")
Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- After cgroup.kill was written to a cgroup, every child cloned into it
with CLONE_INTO_CGROUP was spuriously killed because the fork path
snapshotted the kill counter before resolving the target cgroup
- Releasing an isolated cpuset partition dropped the isolation of CPUs
isolated on the kernel command line
- Selftest and documentation fixes
* tag 'cgroup-for-7.3-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
selftests/cgroup: test clone3() into a previously killed cgroup
cgroup: fix spurious SIGKILL of CLONE_INTO_CGROUP children
selftests/cgroup: Add test for preserving boot-isolated CPUs
cgroup/cpuset: Preserve boot-isolated CPUs on partition release
selftests/cgroup: Drop invalid boot isolation comparison
docs: cgroup-v2: fix misc.events key format description
selftests/cgroup: Fix cg_run_in_subcgroups ignoring arg parameter
selftests/cgroup: set the test plan after the setup checks
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Once cgroup.kill had been written to a cgroup, a stale kill_seq
snapshot (taken in cgroup_css_set_fork() before the target cgroup was
resolved) caused every child subsequently cloned into that cgroup with
clone3(CLONE_INTO_CGROUP) to be SIGKILLed on the spot.
Add a regression test: create a cgroup, kill it while it is empty,
then clone a child into it and check that the child runs and exits
cleanly. On a kernel without the fix, the test fails:
not ok 4 test_cgkill_clone_into_killed
The test is skipped on kernels without clone3() or without
CLONE_INTO_CGROUP.
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Assisted-by: LLM
Signed-off-by: Etienne Perot <eperot@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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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|
Put a CPU isolated at boot into an isolated partition, change the
partition back to member and check that the CPU remains isolated.
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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check_isolcpus() clears ISOLCPUS before rebuilding it from sched domain
data. Comparing that empty value with
/sys/devices/system/cpu/isolated makes the test fail whenever
isolcpus=domain is present.
That sysfs file is generated from HK_TYPE_DOMAIN_BOOT and does not change
when cpuset updates HK_TYPE_DOMAIN. Re-reading it cannot validate dynamic
housekeeping updates. The cpuset.cpus.isolated and sched domain checks
already cover the two dynamic interfaces, so remove the invalid comparison.
This can be reproduced on a kernel booted with isolcpus=domain,15:
# tools/testing/selftests/cgroup/test_cpuset_prs.sh
The test fails its first state-matrix isolation check before the change and
continues past that check afterward.
Fixes: 6df415aa46ec ("cgroup/cpuset: Defer housekeeping_update() calls from CPU hotplug to workqueue")
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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cg_run_in_subcgroups() discards its arg and always passes NULL to cg_run(),
turning the (void *)100 from test_kmem_dead_cgroups() into NULL so no
allocation occurs.
This makes test_kmem_dead_cgroups() falsely pass without exercising the
"dying cgroup with charged slab" scenario it intends to test.
Pass the arg through to cg_run() to fix this.
Fixes: 933dc80ec262 ("kselftests: cgroup: add kernel memory accounting tests")
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
The cgroup tests announce their plan before checking whether cgroup v2 is
available, so on a host without it they promise a number of results and
then skip out after the first one:
TAP version 13
1..3
ok 1 # SKIP cgroup v2 isn't mounted
# Planned tests != run tests (3 != 1)
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
ksft_exit_skip() can only emit a well formed "1..0 # SKIP" line while no
plan has been printed, as the comment above it in kselftest.h points out.
Move ksft_set_plan() below the setup checks that can skip, so that a
skipped run reports:
TAP version 13
1..0 # SKIP cgroup v2 isn't mounted
Several of the tests skip more than once while setting up, for a missing
or unwritable controller as well, so the plan goes after the last of
them. test_core joins its two setup paths at the post_v2_setup label and
sets the plan there.
Reporting each planned test as skipped instead would keep the plan where
it is, but the setup failures here mean the whole test cannot run rather
than its individual cases being skipped, which is what "1..0 # SKIP" is
for.
Fixes: 1dc830ee4c15 ("selftests/cgroup: conform test to KTAP format output")
Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com>
Reviewed-by: Sarthak Sharma <sarthak.sharma@arm.com>
Signed-off-by: Tejun Heo <tj@kernel.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>
|
|
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>
|
|
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>
|
|
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>
|
|
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>
|
|
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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cpuset_hotplug_update_tasks()
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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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
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
...
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|
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>
|
|
system
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>
|
