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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpu.stat now also shows niced CPU time
- Freezer and cpuset optimizations
- Other misc changes
* tag 'cgroup-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Disable cpuset_cpumask_can_shrink() test if not load balancing
cgroup/cpuset: Further optimize code if CONFIG_CPUSETS_V1 not set
cgroup/cpuset: Enforce at most one rebuild_sched_domains_locked() call per operation
cgroup/cpuset: Revert "Allow suppression of sched domain rebuild in update_cpumasks_hier()"
MAINTAINERS: remove Zefan Li
cgroup/freezer: Add cgroup CGRP_FROZEN flag update helper
cgroup/freezer: Reduce redundant traversal for cgroup_freeze
cgroup/bpf: only cgroup v2 can be attached by bpf programs
Revert "cgroup: Fix memory leak caused by missing cgroup_bpf_offline"
selftests/cgroup: Fix compile error in test_cpu.c
cgroup/rstat: Selftests for niced CPU statistics
cgroup/rstat: Tracking cgroup-level niced CPU time
cgroup/cpuset: Fix spelling errors in file kernel/cgroup/cpuset.c
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Pull 'struct fd' class updates from Al Viro:
"The bulk of struct fd memory safety stuff
Making sure that struct fd instances are destroyed in the same scope
where they'd been created, getting rid of reassignments and passing
them by reference, converting to CLASS(fd{,_pos,_raw}).
We are getting very close to having the memory safety of that stuff
trivial to verify"
* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
deal with the last remaing boolean uses of fd_file()
css_set_fork(): switch to CLASS(fd_raw, ...)
memcg_write_event_control(): switch to CLASS(fd)
assorted variants of irqfd setup: convert to CLASS(fd)
do_pollfd(): convert to CLASS(fd)
convert do_select()
convert vfs_dedupe_file_range().
convert cifs_ioctl_copychunk()
convert media_request_get_by_fd()
convert spu_run(2)
switch spufs_calls_{get,put}() to CLASS() use
convert cachestat(2)
convert do_preadv()/do_pwritev()
fdget(), more trivial conversions
fdget(), trivial conversions
privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
o2hb_region_dev_store(): avoid goto around fdget()/fdput()
introduce "fd_pos" class, convert fdget_pos() users to it.
fdget_raw() users: switch to CLASS(fd_raw)
convert vmsplice() to CLASS(fd)
...
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With some recent proposed changes [1] in the deadline server code,
it has caused a test failure in test_cpuset_prs.sh when a change
is being made to an isolated partition. This is due to failing
the cpuset_cpumask_can_shrink() check for SCHED_DEADLINE tasks at
validate_change().
This is actually a false positive as the failed test case involves an
isolated partition with load balancing disabled. The deadline check
is not meaningful in this case and the users should know what they
are doing.
Fix this by doing the cpuset_cpumask_can_shrink() check only when loading
balanced is enabled. Also change its arguments to use effective_cpus
for the current cpuset and user_xcpus() as an approiximation for the
target effective_cpus as the real effective_cpus hasn't been fully
computed yet as this early stage.
As the check isn't comprehensive, there may be false positives or
negatives. We may have to revise the code to do a more thorough check
in the future if this becomes a concern.
[1] https://lore.kernel.org/lkml/82be06c1-6d6d-4651-86c9-bcc828cbcb80@redhat.com/T/#t
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Currently the cpuset code uses group_subsys_on_dfl() to check if we
are running with cgroup v2. If CONFIG_CPUSETS_V1 isn't set, there is
really no need to do this check and we can optimize out some of the
unneeded v1 specific code paths. Introduce a new cpuset_v2() and use it
to replace the cgroup_subsys_on_dfl() check to further optimize the
code.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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operation
Since commit ff0ce721ec21 ("cgroup/cpuset: Eliminate unncessary
sched domains rebuilds in hotplug"), there is only one
rebuild_sched_domains_locked() call per hotplug operation. However,
writing to the various cpuset control files may still casue more than
one rebuild_sched_domains_locked() call to happen in some cases.
Juri had found that two rebuild_sched_domains_locked() calls in
update_prstate(), one from update_cpumasks_hier() and another one from
update_partition_sd_lb() could cause cpuset partition to be created
with null total_bw for DL tasks. IOW, DL tasks may not be scheduled
correctly in such a partition.
A sample command sequence that can reproduce null total_bw is as
follows.
# echo Y >/sys/kernel/debug/sched/verbose
# echo +cpuset >/sys/fs/cgroup/cgroup.subtree_control
# mkdir /sys/fs/cgroup/test
# echo 0-7 > /sys/fs/cgroup/test/cpuset.cpus
# echo 6-7 > /sys/fs/cgroup/test/cpuset.cpus.exclusive
# echo root >/sys/fs/cgroup/test/cpuset.cpus.partition
Fix this double rebuild_sched_domains_locked() calls problem
by replacing existing calls with cpuset_force_rebuild() except
the rebuild_sched_domains_cpuslocked() call at the end of
cpuset_handle_hotplug(). Checking of the force_sd_rebuild flag is
now done at the end of cpuset_write_resmask() and update_prstate()
to determine if rebuild_sched_domains_locked() should be called or not.
The cpuset v1 code can still call rebuild_sched_domains_locked()
directly as double rebuild_sched_domains_locked() calls is not possible.
Reported-by: Juri Lelli <juri.lelli@redhat.com>
Closes: https://lore.kernel.org/lkml/ZyuUcJDPBln1BK1Y@jlelli-thinkpadt14gen4.remote.csb/
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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update_cpumasks_hier()"
Revert commit 3ae0b773211e ("cgroup/cpuset: Allow suppression of sched
domain rebuild in update_cpumasks_hier()") to allow for an alternative
way to suppress unnecessary rebuild_sched_domains_locked() calls in
update_cpumasks_hier() and elsewhere in a following commit.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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reference acquired there by fget_raw() is not stashed anywhere -
we could as well borrow instead.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Add help to update cgroup CGRP_FROZEN flag. Both cgroup_propagate_frozen
and cgroup_update_frozen functions update CGRP_FROZEN flag, this makes
code concise.
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Whether a cgroup is frozen is determined solely by whether it is set to
to be frozen and whether its parent is frozen. Currently, when is cgroup
is frozen or unfrozen, it iterates through the entire subtree to freeze
or unfreeze its descentdants. However, this is unesessary for a cgroup
that does not change its effective frozen status. This path aims to skip
the subtree if its parent does not have a change in effective freeze.
For an example, subtree like, a-b-c-d-e-f-g, when a is frozen, the
entire tree is frozen. If we freeze b and c again, it is unesessary to
iterate d, e, f and g. So does that If we unfreeze b/c.
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Only cgroup v2 can be attached by bpf programs, so this patch introduces
that cgroup_bpf_inherit and cgroup_bpf_offline can only be called in
cgroup v2, and this can fix the memleak mentioned by commit 04f8ef5643bc
("cgroup: Fix memory leak caused by missing cgroup_bpf_offline"), which
has been reverted.
Fixes: 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Fixes: 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Link: https://lore.kernel.org/cgroups/aka2hk5jsel5zomucpwlxsej6iwnfw4qu5jkrmjhyfhesjlfdw@46zxhg5bdnr7/
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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This reverts commit 04f8ef5643bcd8bcde25dfdebef998aea480b2ba.
Only cgroup v2 can be attached by cgroup by BPF programs. Revert this
commit and cgroup_bpf_inherit and cgroup_bpf_offline won't be called in
cgroup v1. The memory leak issue will be fixed with next patch.
Fixes: 04f8ef5643bc ("cgroup: Fix memory leak caused by missing cgroup_bpf_offline")
Link: https://lore.kernel.org/cgroups/aka2hk5jsel5zomucpwlxsej6iwnfw4qu5jkrmjhyfhesjlfdw@46zxhg5bdnr7/
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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cgroup.max.depth is the maximum allowed descent depth below the current
cgroup. If the actual descent depth is equal or larger, an attempt to
create a new child cgroup will fail. However due to the cgroup->max_depth
is of int type and having the default value INT_MAX, the condition
'level > cgroup->max_depth' will never be satisfied, and it will cause
an overflow of the level after it reaches to INT_MAX.
Fix it by starting the level from 0 and using '>=' instead.
It's worth mentioning that this issue is unlikely to occur in reality,
as it's impossible to have a depth of INT_MAX hierarchy, but should be
be avoided logically.
Fixes: 1a926e0bbab8 ("cgroup: implement hierarchy limits")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Cgroup-level CPU statistics currently include time spent on
user/system processes, but do not include niced CPU time (despite
already being tracked). This patch exposes niced CPU time to the
userspace, allowing users to get a better understanding of their
hardware limits and can facilitate more informed workload distribution.
A new field 'ntime' is added to struct cgroup_base_stat as opposed to
struct task_cputime to minimize footprint.
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Corrected the spelling errors repoted by codespell as follows:
temparary ==> temporary
Proprogate ==> Propagate
constrainted ==> constrained
Signed-off-by: Everest K.C. <everestkc@everestkc.com.np>
Acked-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/viro/vfs
Pull 'struct fd' updates from Al Viro:
"Just the 'struct fd' layout change, with conversion to accessor
helpers"
* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add struct fd constructors, get rid of __to_fd()
struct fd: representation change
introduce fd_file(), convert all accessors to it.
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Along with the usual shower of singleton patches, notable patch series
in this pull request are:
- "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
- "Some cleanups for shmem" from Baolin Wang. No functional changes -
mode code reuse, better function naming, logic simplifications.
- "mm: some small page fault cleanups" from Josef Bacik. No
functional changes - code cleanups only.
- "Various memory tiering fixes" from Zi Yan. A small fix and a
little cleanup.
- "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
- "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
Butt. This is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at
all used 16k. Useful for some system tuning things, but
partivularly useful for "the dynamic kernel stack project".
- "kmemleak: support for percpu memory leak detect" from Pavel
Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.
- "mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
- "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
David Hildenbrand. Improves PTE/PMD splitlock detection, makes
powerpc/8xx work correctly by design rather than by accident.
- "mm: remove arch_make_page_accessible()" from David Hildenbrand.
Some folio conversions which make arch_make_page_accessible()
unneeded.
- "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
Finkel. Cleans up and fixes our handling of the resetting of the
cgroup/process peak-memory-use detector.
- "Make core VMA operations internal and testable" from Lorenzo
Stoakes. Rationalizaion and encapsulation of the VMA manipulation
APIs. With a view to better enable testing of the VMA functions,
even from a userspace-only harness.
- "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
issues in the zswap global shrinker, resulting in improved
performance.
- "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
in some missing info in /proc/zoneinfo.
- "mm: replace follow_page() by folio_walk" from David Hildenbrand.
Code cleanups and rationalizations (conversion to folio_walk())
resulting in the removal of follow_page().
- "improving dynamic zswap shrinker protection scheme" from Nhat
Pham. Some tuning to improve zswap's dynamic shrinker. Significant
reductions in swapin and improvements in performance are shown.
- "mm: Fix several issues with unaccepted memory" from Kirill
Shutemov. Improvements to the new unaccepted memory feature,
- "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
DAX PUDs. This was missing, although nobody seems to have notied
yet.
- "Introduce a store type enum for the Maple tree" from Sidhartha
Kumar. Cleanups and modest performance improvements for the maple
tree library code.
- "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
more cgroup v1 remnants away from the v2 memcg code.
- "memcg: initiate deprecation of v1 features" from Shakeel Butt.
Adds various warnings telling users that memcg v1 features are
deprecated.
- "mm: swap: mTHP swap allocator base on swap cluster order" from
Chris Li. Greatly improves the success rate of the mTHP swap
allocation.
- "mm: introduce numa_memblks" from Mike Rapoport. Moves various
disparate per-arch implementations of numa_memblk code into generic
code.
- "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
- "support large folio swap-out and swap-in for shmem" from Baolin
Wang. With this series we no longer split shmem large folios into
simgle-page folios when swapping out shmem.
- "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
performance improvements and code reductions for gigantic folios.
- "support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
- "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
- "Increase the number of bits available in page_type" from Matthew
Wilcox. Increases the number of bits available in page_type!
- "Simplify the page flags a little" from Matthew Wilcox. Many legacy
page flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
- "mm: store zero pages to be swapped out in a bitmap" from Usama
Arif. An optimization which permits us to avoid writing/reading
zero-filled zswap pages to backing store.
- "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
window which occurs when a MAP_FIXED operqtion is occurring during
an unrelated vma tree walk.
- "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
the vma_merge() functionality, making ot cleaner, more testable and
better tested.
- "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
Minor fixups of DAMON selftests and kunit tests.
- "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
Code cleanups and folio conversions.
- "Shmem mTHP controls and stats improvements" from Ryan Roberts.
Cleanups for shmem controls and stats.
- "mm: count the number of anonymous THPs per size" from Barry Song.
Expose additional anon THP stats to userspace for improved tuning.
- "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
folio conversions and removal of now-unused page-based APIs.
- "replace per-quota region priorities histogram buffer with
per-context one" from SeongJae Park. DAMON histogram
rationalization.
- "Docs/damon: update GitHub repo URLs and maintainer-profile" from
SeongJae Park. DAMON documentation updates.
- "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
improve related doc and warn" from Jason Wang: fixes usage of page
allocator __GFP_NOFAIL and GFP_ATOMIC flags.
- "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
This was overprovisioning THPs in sparsely accessed memory areas.
- "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
Add support for zram run-time compression algorithm tuning.
- "mm: Care about shadow stack guard gap when getting an unmapped
area" from Mark Brown. Fix up the various arch_get_unmapped_area()
implementations to better respect guard areas.
- "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
of mem_cgroup_iter() and various code cleanups.
- "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
- "resource: Fix region_intersects() vs add_memory_driver_managed()"
from Huang Ying. Fix a bug in region_intersects() for systems with
CXL memory.
- "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
a couple more code paths to correctly recover from the encountering
of poisoned memry.
- "mm: enable large folios swap-in support" from Barry Song. Support
the swapin of mTHP memory into appropriately-sized folios, rather
than into single-page folios"
* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
zram: free secondary algorithms names
uprobes: turn xol_area->pages[2] into xol_area->page
uprobes: introduce the global struct vm_special_mapping xol_mapping
Revert "uprobes: use vm_special_mapping close() functionality"
mm: support large folios swap-in for sync io devices
mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
set_memory: add __must_check to generic stubs
mm/vma: return the exact errno in vms_gather_munmap_vmas()
memcg: cleanup with !CONFIG_MEMCG_V1
mm/show_mem.c: report alloc tags in human readable units
mm: support poison recovery from copy_present_page()
mm: support poison recovery from do_cow_fault()
resource, kunit: add test case for region_intersects()
resource: make alloc_free_mem_region() works for iomem_resource
mm: z3fold: deprecate CONFIG_Z3FOLD
vfio/pci: implement huge_fault support
mm/arm64: support large pfn mappings
mm/x86: support large pfn mappings
...
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This is a followup to CONFIG-urability of cpuset and memory controllers
for v1 hierarchies. Make the output in /proc/cgroups reflect that
!CONFIG_CPUSETS_V1 is like !CONFIG_CPUSETS and
!CONFIG_MEMCG_V1 is like !CONFIG_MEMCG.
The intended effect is that hiding the unavailable controllers will hint
users not to try mounting them on v1.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The configs that disable some v1 controllers would still allow mounting
them but with no controller-specific files. (Making such hierarchies
equivalent to named v1 hierarchies.) To achieve behavior consistent with
actual out-compilation of a whole controller, the mounts should treat
respective controllers as non-existent.
Wrap implementation into a helper function, leverage legacy_files to
detect compiled out controllers. The effect is that mounts on v1 would
fail and produce a message like:
[ 1543.999081] cgroup: Unknown subsys name 'memory'
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The cpuset filesystem is a legacy interface to cpuset controller with
(pre-)v1 features. It makes little sense to co-mount it on systems
without cpuset v1, so do not build it when cpuset v1 is not built
neither.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Patch series "Improve mem_cgroup_iter()", v4.
Incremental cgroup iteration is being used again [1]. This patchset
improves the reliability of mem_cgroup_iter(). It also improves
simplicity and code readability.
[1] https://lore.kernel.org/20240514202641.2821494-1-hannes@cmpxchg.org/
This patch (of 5):
Explicitly document that css sibling/descendant linkage is protected by
cgroup_mutex or RCU. Also, document in css_next_descendant_pre() and
similar functions that it isn't necessary to hold a ref on @pos.
The following changes in this patchset rely on this clarification for
simplification in memcg iteration code.
Link: https://lkml.kernel.org/r/20240905003058.1859929-1-kinseyho@google.com
Link: https://lkml.kernel.org/r/20240905003058.1859929-2-kinseyho@google.com
Suggested-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The newly created cpuset-v1.c file uses cpus_read_lock/unlock() functions
which are defined in cpu.h but not included in cpuset-internal.h yet
leading to compilation error under certain kernel configurations. Fix it
by moving the cpu.h include from cpuset.c to cpuset-internal.h. While
at it, sort the include files in alphabetic order.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408311612.mQTuO946-lkp@intel.com/
Fixes: 047b83097448 ("cgroup/cpuset: move relax_domain_level to cpuset-v1.c")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Patch series "mm, memcg: cg2 memory{.swap,}.peak write handlers", v7.
This patch (of 2):
Other mechanisms for querying the peak memory usage of either a process or
v1 memory cgroup allow for resetting the high watermark. Restore parity
with those mechanisms, but with a less racy API.
For example:
- Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets
the high watermark.
- writing "5" to the clear_refs pseudo-file in a processes's proc
directory resets the peak RSS.
This change is an evolution of a previous patch, which mostly copied the
cgroup v1 behavior, however, there were concerns about races/ownership
issues with a global reset, so instead this change makes the reset
filedescriptor-local.
Writing any non-empty string to the memory.peak and memory.swap.peak
pseudo-files reset the high watermark to the current usage for subsequent
reads through that same FD.
Notably, following Johannes's suggestion, this implementation moves the
O(FDs that have written) behavior onto the FD write(2) path. Instead, on
the page-allocation path, we simply add one additional watermark to
conditionally bump per-hierarchy level in the page-counter.
Additionally, this takes Longman's suggestion of nesting the
page-charging-path checks for the two watermarks to reduce the number of
common-case comparisons.
This behavior is particularly useful for work scheduling systems that need
to track memory usage of worker processes/cgroups per-work-item. Since
memory can't be squeezed like CPU can (the OOM-killer has opinions), these
systems need to track the peak memory usage to compute system/container
fullness when binpacking workitems.
Most notably, Vimeo's use-case involves a system that's doing global
binpacking across many Kubernetes pods/containers, and while we can use
PSI for some local decisions about overload, we strive to avoid packing
workloads too tightly in the first place. To facilitate this, we track
the peak memory usage. However, since we run with long-lived workers (to
amortize startup costs) we need a way to track the high watermark while a
work-item is executing. Polling runs the risk of missing short spikes
that last for timescales below the polling interval, and peak memory
tracking at the cgroup level is otherwise perfect for this use-case.
As this data is used to ensure that binpacked work ends up with sufficient
headroom, this use-case mostly avoids the inaccuracies surrounding
reclaimable memory.
Link: https://lkml.kernel.org/r/20240730231304.761942-1-davidf@vimeo.com
Link: https://lkml.kernel.org/r/20240729143743.34236-1-davidf@vimeo.com
Link: https://lkml.kernel.org/r/20240729143743.34236-2-davidf@vimeo.com
Signed-off-by: David Finkel <davidf@vimeo.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This patch introduces CONFIG_CPUSETS_V1 and guard cpuset-v1 code under
CONFIG_CPUSETS_V1. The default value of CONFIG_CPUSETS_V1 is N, so that
user who adopted v2 don't have 'pay' for cpuset v1.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Some functions name declared in cpuset-internel.h are generic. To avoid
confilicting with other variables for the same name, rename these
functions with cpuset_/cpuset1_ prefix to make them unique to cpuset.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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Move legacy cpuset controller interfaces files and corresponding code
into cpuset-v1.c. 'update_flag', 'cpuset_write_resmask' and
'cpuset_common_seq_show' are also used for v1, so declare them in
cpuset-internal.h.
'cpuset_write_s64', 'cpuset_read_s64' and 'fmeter_getrate' are only used
cpuset-v1.c now, make it static.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The validate_change_legacy functions is used for v1, move it to
cpuset-v1.c. And two micro 'cpuset_for_each_child' and
'cpuset_for_each_descendant_pre' are common for v1 and v2, move them to
cpuset-internal.h.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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There are some differents about hotplug update between cpuset v1 and
cpuset v2. Move the legacy code to cpuset-v1.c.
'update_tasks_cpumask' and 'update_tasks_nodemask' are both used in cpuset
v1 and cpuset v2, declare them in cpuset-internal.h.
The change from original code is that use callback_lock helpers to get
callback_lock lock/unlock.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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To modify cpuset, both cpuset_mutex and callback_lock are needed. Add
helpers for cpuset-v1 to get callback_lock.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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'memory_spread' is only set in cpuset v1. move corresponding code into
cpuset-v1.c.
Currently, 'cpuset_update_task_spread_flags' and 'update_tasks_flags' are
exposed to cpuset.c.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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Setting domain level is not supported at cpuset v2, so move corresponding
code into cpuset-v1.c.
The 'cpuset_write_s64' and 'cpuset_read_s64' are only used for setting
domain level, move them to cpuset-v1.c. Currently, expose to cpuset.c.
After cpuset legacy interface files are move to cpuset-v1.c, they can
be static. The 'rebuild_sched_domains_locked' is exposed to cpuset-v1.c.
The change from original code is that using 'cpuset_lock' and
'cpuset_unlock' functions to lock or unlock cpuset_mutex.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Collection of memory_pressure can be enabled by writing 1 to the cpuset
file 'memory_pressure_enabled', which is only for cpuset-v1. Therefore,
move the corresponding code to cpuset-v1.c.
Currently, the 'fmeter_init' and 'fmeter_getrate' functions are called
at cpuset.c, so expose them to cpuset.c.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Move some declarations that will be used for cpuset v1 and v2,
including 'cpuset struct', 'cpuset_flagbits_t', cpuset_filetype_t,etc.
No logical change.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
This patch introduces the cgroup/cpuset-v1.c source file which will be
used for all legacy (cgroup v1) cpuset cgroup code. It also introduces
cgroup/cpuset-internal.h to keep declarations shared between
cgroup/cpuset.c and cpuset/cpuset-v1.c.
As of now, let's compile it if CONFIG_CPUSET is set. Later on it can be
switched to use a separate config option, so that the legacy code won't be
compiled if not required.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
With the "isolcpus" boot command line parameter, we are able to
create isolated CPUs at boot time. These isolated CPUs aren't fully
accounted for in the cpuset code. For instance, the root cgroup's
"cpuset.cpus.isolated" control file does not include the boot time
isolated CPUs. Fix that by looking for pre-isolated CPUs at init time.
The prstate_housekeeping_conflict() function does check the
HK_TYPE_DOMAIN housekeeping cpumask to make sure that CPUs outside of it
can only be used in isolated partition. Given the fact that we are going
to make housekeeping cpumasks dynamic, the current check may not be right
anymore. Save the boot time HK_TYPE_DOMAIN cpumask and check against
it instead of the upcoming dynamic HK_TYPE_DOMAIN housekeeping cpumask.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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use_parent_ecpus is used to track whether the children are using the
parent's effective_cpus. When a parent's effective_cpus is changed
due to changes in a child partition's effective_xcpus, any child
using parent'effective_cpus must call update_cpumasks_hier. However,
if a child is not a valid partition, it is sufficient to determine
whether to call update_cpumasks_hier based on whether the child's
effective_cpus is going to change. To make the code more succinct,
it is suggested to remove use_parent_ecpus.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Both fetch_xcpus and user_xcpus functions are used to retrieve the value
of exclusive_cpus. If exclusive_cpus is not set, cpus_allowed is the
implicit value used as exclusive in a local partition. I can not imagine
a scenario where effective_xcpus is not empty when exclusive_cpus is
empty. Therefore, I suggest removing the fetch_xcpus function.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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When enable a remote partition, I found that:
cd /sys/fs/cgroup/
mkdir test
mkdir test/test1
echo +cpuset > cgroup.subtree_control
echo +cpuset > test/cgroup.subtree_control
echo 3 > test/test1/cpuset.cpus
echo root > test/test1/cpuset.cpus.partition
cat test/test1/cpuset.cpus.partition
root invalid (Parent is not a partition root)
The parent of a remote partition could not be a root. This is due to the
emtpy effective_xcpus. It would be better to prompt the message "invalid
cpu list in cpuset.cpus.exclusive".
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The comment in cgroup_file_write is missing some interfaces, such as
'cgroup.threads'. All delegatable files are listed in
'/sys/kernel/cgroup/delegate', so update the comment in cgroup_file_write.
Besides, add a statement that files outside the namespace shouldn't be
visible from inside the delegated namespace.
tj: Reflowed text for consistency.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
This commit converts (almost) all of f.file to
fd_file(f). It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).
NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).
[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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It turns out that the WARN_ON_ONCE() call in css_release_work_fn
introduced by commit ab0312526867 ("cgroup: Show # of subsystem CSSes
in cgroup.stat") is incorrect. Although css->nr_descendants must be
0 when a css is released and ready to be freed, the corresponding
cgrp->nr_dying_subsys[ss->id] may not be 0 if a subsystem is activated
and deactivated multiple times with one or more of its previous
activation leaving behind dying csses.
Fix the incorrect warning by removing the cgrp->nr_dying_subsys check.
Fixes: ab0312526867 ("cgroup: Show # of subsystem CSSes in cgroup.stat")
Closes: https://lore.kernel.org/cgroups/6f301773-2fce-4602-a391-8af7ef00b2fb@redhat.com/T/#t
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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With the previous commit that eliminates the overlapping partition
root corner cases in the hotplug code, the partition roots passed down
to generate_sched_domains() should not have overlapping CPUs. Enable
overlapping cpuset check for v2 and warn if that happens.
This patch also has the benefit of increasing test coverage of the new
Union-Find cpuset merging code to cgroup v2.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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cgroup/for-6.12 is about to receive updates that are dependent on changes
from both for-6.11-fixes and for-6.12. Pull in for-6.11-fixes.
Signed-off-by: Tejun Heo <tj@kernel.org>
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It was found that some hotplug operations may cause multiple
rebuild_sched_domains_locked() calls. Some of those intermediate calls
may use cpuset states not in the final correct form leading to incorrect
sched domain setting.
Fix this problem by using the existing force_rebuild flag to inhibit
immediate rebuild_sched_domains_locked() calls if set and only doing
one final call at the end. Also renaming the force_rebuild flag to
force_sd_rebuild to make its meaning for clear.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
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cpus.exclusive not set
Commit e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for
v2") adds a user writable cpuset.cpus.exclusive file for setting
exclusive CPUs to be used for the creation of partitions. Since then
effective_xcpus depends on both the cpuset.cpus and cpuset.cpus.exclusive
setting. If cpuset.cpus.exclusive is set, effective_xcpus will depend
only on cpuset.cpus.exclusive. When it is not set, effective_xcpus
will be set according to the cpuset.cpus value when the cpuset becomes
a valid partition root.
When cpuset.cpus is being cleared by the user, effective_xcpus should
only be cleared when cpuset.cpus.exclusive is not set. However, that
is not currently the case.
# cd /sys/fs/cgroup/
# mkdir test
# echo +cpuset > cgroup.subtree_control
# cd test
# echo 3 > cpuset.cpus.exclusive
# cat cpuset.cpus.exclusive.effective
3
# echo > cpuset.cpus
# cat cpuset.cpus.exclusive.effective // was cleared
Fix it by clearing effective_xcpus only if cpuset.cpus.exclusive is
not set.
Fixes: e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2")
Cc: stable@vger.kernel.org # v6.7+
Reported-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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We find a bug as below:
BUG: unable to handle page fault for address: 00000003
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 3 PID: 358 Comm: bash Tainted: G W I 6.6.0-10893-g60d6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/4
RIP: 0010:partition_sched_domains_locked+0x483/0x600
Code: 01 48 85 d2 74 0d 48 83 05 29 3f f8 03 01 f3 48 0f bc c2 89 c0 48 9
RSP: 0018:ffffc90000fdbc58 EFLAGS: 00000202
RAX: 0000000100000003 RBX: ffff888100b3dfa0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000002fe80
RBP: ffff888100b3dfb0 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90000fdbcb0 R11: 0000000000000004 R12: 0000000000000002
R13: ffff888100a92b48 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f44a5425740(0000) GS:ffff888237d80000(0000) knlGS:0000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100030973 CR3: 000000010722c000 CR4: 00000000000006e0
Call Trace:
<TASK>
? show_regs+0x8c/0xa0
? __die_body+0x23/0xa0
? __die+0x3a/0x50
? page_fault_oops+0x1d2/0x5c0
? partition_sched_domains_locked+0x483/0x600
? search_module_extables+0x2a/0xb0
? search_exception_tables+0x67/0x90
? kernelmode_fixup_or_oops+0x144/0x1b0
? __bad_area_nosemaphore+0x211/0x360
? up_read+0x3b/0x50
? bad_area_nosemaphore+0x1a/0x30
? exc_page_fault+0x890/0xd90
? __lock_acquire.constprop.0+0x24f/0x8d0
? __lock_acquire.constprop.0+0x24f/0x8d0
? asm_exc_page_fault+0x26/0x30
? partition_sched_domains_locked+0x483/0x600
? partition_sched_domains_locked+0xf0/0x600
rebuild_sched_domains_locked+0x806/0xdc0
update_partition_sd_lb+0x118/0x130
cpuset_write_resmask+0xffc/0x1420
cgroup_file_write+0xb2/0x290
kernfs_fop_write_iter+0x194/0x290
new_sync_write+0xeb/0x160
vfs_write+0x16f/0x1d0
ksys_write+0x81/0x180
__x64_sys_write+0x21/0x30
x64_sys_call+0x2f25/0x4630
do_syscall_64+0x44/0xb0
entry_SYSCALL_64_after_hwframe+0x78/0xe2
RIP: 0033:0x7f44a553c887
It can be reproduced with cammands:
cd /sys/fs/cgroup/
mkdir test
cd test/
echo +cpuset > ../cgroup.subtree_control
echo root > cpuset.cpus.partition
cat /sys/fs/cgroup/cpuset.cpus.effective
0-3
echo 0-3 > cpuset.cpus // taking away all cpus from root
This issue is caused by the incorrect rebuilding of scheduling domains.
In this scenario, test/cpuset.cpus.partition should be an invalid root
and should not trigger the rebuilding of scheduling domains. When calling
update_parent_effective_cpumask with partcmd_update, if newmask is not
null, it should recheck newmask whether there are cpus is available
for parect/cs that has tasks.
Fixes: 0c7f293efc87 ("cgroup/cpuset: Add cpuset.cpus.exclusive.effective for v2")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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|
According to the implementation of cgroup_css_set_fork(), it will fail
if cset cannot be found and the can_fork/cancel_fork methods will not
be called in this case, which means that the argument 'cset' for these
methods must not be NULL, so remove the unrechable paths in them.
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
Cgroup subsystem state (CSS) is an abstraction in the cgroup layer to
help manage different structures in various cgroup subsystems by being
an embedded element inside a larger structure like cpuset or mem_cgroup.
The /proc/cgroups file shows the number of cgroups for each of the
subsystems. With cgroup v1, the number of CSSes is the same as the
number of cgroups. That is not the case anymore with cgroup v2. The
/proc/cgroups file cannot show the actual number of CSSes for the
subsystems that are bound to cgroup v2.
So if a v2 cgroup subsystem is leaking cgroups (usually memory cgroup),
we can't tell by looking at /proc/cgroups which cgroup subsystems may
be responsible.
As cgroup v2 had deprecated the use of /proc/cgroups, the hierarchical
cgroup.stat file is now being extended to show the number of live and
dying CSSes associated with all the non-inhibited cgroup subsystems that
have been bound to cgroup v2. The number includes CSSes in the current
cgroup as well as in all the descendants underneath it. This will help
us pinpoint which subsystems are responsible for the increasing number
of dying (nr_dying_descendants) cgroups.
The CSSes dying counts are stored in the cgroup structure itself
instead of inside the CSS as suggested by Johannes. This will allow
us to accurately track dying counts of cgroup subsystems that have
recently been disabled in a cgroup. It is now possible that a zero
subsystem number is coupled with a non-zero dying subsystem number.
The cgroup-v2.rst file is updated to discuss this new behavior.
With this patch applied, a sample output from root cgroup.stat file
was shown below.
nr_descendants 56
nr_subsys_cpuset 1
nr_subsys_cpu 43
nr_subsys_io 43
nr_subsys_memory 56
nr_subsys_perf_event 57
nr_subsys_hugetlb 1
nr_subsys_pids 56
nr_subsys_rdma 1
nr_subsys_misc 1
nr_dying_descendants 30
nr_dying_subsys_cpuset 0
nr_dying_subsys_cpu 0
nr_dying_subsys_io 0
nr_dying_subsys_memory 30
nr_dying_subsys_perf_event 0
nr_dying_subsys_hugetlb 0
nr_dying_subsys_pids 0
nr_dying_subsys_rdma 0
nr_dying_subsys_misc 0
Another sample output from system.slice/cgroup.stat was:
nr_descendants 34
nr_subsys_cpuset 0
nr_subsys_cpu 32
nr_subsys_io 32
nr_subsys_memory 34
nr_subsys_perf_event 35
nr_subsys_hugetlb 0
nr_subsys_pids 34
nr_subsys_rdma 0
nr_subsys_misc 0
nr_dying_descendants 30
nr_dying_subsys_cpuset 0
nr_dying_subsys_cpu 0
nr_dying_subsys_io 0
nr_dying_subsys_memory 30
nr_dying_subsys_perf_event 0
nr_dying_subsys_hugetlb 0
nr_dying_subsys_pids 0
nr_dying_subsys_rdma 0
nr_dying_subsys_misc 0
Note that 'debug' controller wasn't used to provide this information because
the controller is not recommended in productions kernels, also many of them
won't enable CONFIG_CGROUP_DEBUG by default.
Similar information could be retrieved with debuggers like drgn but that's
also not always available (e.g. lockdown) and the additional cost of runtime
tracking here is deemed marginal.
tj: Added Michal's paragraphs on why this is not added the debug controller
to the commit message.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Cc: Michal Koutný <mkoutny@suse.com>
Link: http://lkml.kernel.org/r/20240715150034.2583772-1-longman@redhat.com
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
The process of constructing scheduling domains
involves multiple loops and repeated evaluations, leading to numerous
redundant and ineffective assessments that impact code efficiency.
Here, we use union-find to optimize the merging of cpumasks. By employing
path compression and union by rank, we effectively reduce the number of
lookups and merge comparisons.
Signed-off-by: Xavier <xavier_qy@163.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
There are several functions to decrease attach_in_progress, and they
will wake up cpuset_attach_wq when attach_in_progress is zero. So,
add a helper to make it concise.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
