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2025-04-20cgroup/cpuset: Fix race between newly created partition and dying oneWaiman Long1-1/+1
[ Upstream commit a22b3d54de94f82ca057cc2ebf9496fa91ebf698 ] There is a possible race between removing a cgroup diectory that is a partition root and the creation of a new partition. The partition to be removed can be dying but still online, it doesn't not currently participate in checking for exclusive CPUs conflict, but the exclusive CPUs are still there in subpartitions_cpus and isolated_cpus. These two cpumasks are global states that affect the operation of cpuset partitions. The exclusive CPUs in dying cpusets will only be removed when cpuset_css_offline() function is called after an RCU delay. As a result, it is possible that a new partition can be created with exclusive CPUs that overlap with those of a dying one. When that dying partition is finally offlined, it removes those overlapping exclusive CPUs from subpartitions_cpus and maybe isolated_cpus resulting in an incorrect CPU configuration. This bug was found when a warning was triggered in remote_partition_disable() during testing because the subpartitions_cpus mask was empty. One possible way to fix this is to iterate the dying cpusets as well and avoid using the exclusive CPUs in those dying cpusets. However, this can still cause random partition creation failures or other anomalies due to racing. A better way to fix this race is to reset the partition state at the moment when a cpuset is being killed. Introduce a new css_killed() CSS function pointer and call it, if defined, before setting CSS_DYING flag in kill_css(). Also update the css_is_dying() helper to use the CSS_DYING flag introduced by commit 33c35aa48178 ("cgroup: Prevent kill_css() from being called more than once") for proper synchronization. Add a new cpuset_css_killed() function to reset the partition state of a valid partition root if it is being killed. Fixes: ee8dde0cd2ce ("cpuset: Add new v2 cpuset.sched.partition flag") Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-21Merge tag 'sched_ext-for-6.12' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext support from Tejun Heo: "This implements a new scheduler class called ‘ext_sched_class’, or sched_ext, which allows scheduling policies to be implemented as BPF programs. The goals of this are: - Ease of experimentation and exploration: Enabling rapid iteration of new scheduling policies. - Customization: Building application-specific schedulers which implement policies that are not applicable to general-purpose schedulers. - Rapid scheduler deployments: Non-disruptive swap outs of scheduling policies in production environments" See individual commits for more documentation, but also the cover letter for the latest series: Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/ * tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits) sched: Move update_other_load_avgs() to kernel/sched/pelt.c sched_ext: Don't trigger ops.quiescent/runnable() on migrations sched_ext: Synchronize bypass state changes with rq lock scx_qmap: Implement highpri boosting sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq() sched_ext: Compact struct bpf_iter_scx_dsq_kern sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq() sched_ext: Move consume_local_task() upward sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq() sched_ext: Reorder args for consume_local/remote_task() sched_ext: Restructure dispatch_to_local_dsq() sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON sched_ext: Refactor consume_remote_task() sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate sched_ext: Add missing static to scx_dump_data sched_ext: Add missing static to scx_has_op[] sched_ext: Temporarily work around pick_task_scx() being called without balance_scx() sched_ext: Add a cgroup scheduler which uses flattened hierarchy sched_ext: Add cgroup support ...
2024-09-01mm, memcg: cg2 memory{.swap,}.peak write handlersDavid Finkel1-0/+3
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>
2024-07-30Merge tag 'v6.11-rc1' into for-6.12Tejun Heo1-1/+0
Linux 6.11-rc1
2024-06-24cpumask: cleanup core headers inclusionYury Norov1-1/+0
Many core headers include cpumask.h for nothing. Drop it. Link: https://lkml.kernel.org/r/20240528005648.182376-6-yury.norov@gmail.com Signed-off-by: Yury Norov <yury.norov@gmail.com> Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com> Cc: Anna-Maria Behnsen <anna-maria@linutronix.de> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Yury Norov <yury.norov@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-18sched: Factor out cgroup weight conversion functionsTejun Heo1-2/+2
Factor out sched_weight_from/to_cgroup() which convert between scheduler shares and cgroup weight. No functional change. The factored out functions will be used by a new BPF extensible sched_class so that the weights can be exposed to the BPF programs in a way which is consistent cgroup weights and easier to interpret. The weight conversions will be used regardless of cgroup usage. It's just borrowing the cgroup weight range as it's more intuitive. CGROUP_WEIGHT_MIN/DFL/MAX constants are moved outside CONFIG_CGROUPS so that the conversion helpers can always be defined. v2: The helpers are now defined regardless of COFNIG_CGROUPS. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: David Vernet <dvernet@meta.com> Acked-by: Josh Don <joshdon@google.com> Acked-by: Hao Luo <haoluo@google.com> Acked-by: Barret Rhoden <brho@google.com>
2024-04-16cgroup/rstat: add cgroup_rstat_lock helpers and tracepointsJesper Dangaard Brouer1-1/+1
This commit enhances the ability to troubleshoot the global cgroup_rstat_lock by introducing wrapper helper functions for the lock along with associated tracepoints. Although global, the cgroup_rstat_lock helper APIs and tracepoints take arguments such as cgroup pointer and cpu_in_loop variable. This adjustment is made because flushing occurs per cgroup despite the lock being global. Hence, when troubleshooting, it's important to identify the relevant cgroup. The cpu_in_loop variable is necessary because the global lock may be released within the main flushing loop that traverses CPUs. In the tracepoints, the cpu_in_loop value is set to -1 when acquiring the main lock; otherwise, it denotes the CPU number processed last. The new feature in this patchset is detecting when lock is contended. The tracepoints are implemented with production in mind. For minimum overhead attach to cgroup:cgroup_rstat_lock_contended, which only gets activated when trylock detects lock is contended. A quick production check for issues could be done via this perf commands: perf record -g -e cgroup:cgroup_rstat_lock_contended Next natural question would be asking how long time do lock contenders wait for obtaining the lock. This can be answered by measuring the time between cgroup:cgroup_rstat_lock_contended and cgroup:cgroup_rstat_locked when args->contended is set. Like this bpftrace script: bpftrace -e ' tracepoint:cgroup:cgroup_rstat_lock_contended {@start[tid]=nsecs} tracepoint:cgroup:cgroup_rstat_locked { if (args->contended) { @wait_ns=hist(nsecs-@start[tid]); delete(@start[tid]);}} interval:s:1 {time("%H:%M:%S "); print(@wait_ns); }' Extending with time spend holding the lock will be more expensive as this also looks at all the non-contended cases. Like this bpftrace script: bpftrace -e ' tracepoint:cgroup:cgroup_rstat_lock_contended {@start[tid]=nsecs} tracepoint:cgroup:cgroup_rstat_locked { @locked[tid]=nsecs; if (args->contended) { @wait_ns=hist(nsecs-@start[tid]); delete(@start[tid]);}} tracepoint:cgroup:cgroup_rstat_unlock { @locked_ns=hist(nsecs-@locked[tid]); delete(@locked[tid]);} interval:s:1 {time("%H:%M:%S "); print(@wait_ns);print(@locked_ns); }' Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-11-09cgroup: Add a new helper for cgroup1 hierarchyYafang Shao1-1/+3
A new helper is added for cgroup1 hierarchy: - task_get_cgroup1 Acquires the associated cgroup of a task within a specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its hierarchy ID. This helper function is added to facilitate the tracing of tasks within a particular container or cgroup dir in BPF programs. It's important to note that this helper is designed specifically for cgroup1 only. tj: Use irsqsave/restore as suggested by Hou Tao <houtao@huaweicloud.com>. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: Hou Tao <houtao@huaweicloud.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-10-19cgroup: Prepare for using css_task_iter_*() in BPFChuyi Zhou1-7/+5
This patch makes some preparations for using css_task_iter_*() in BPF Program. 1. Flags CSS_TASK_ITER_* are #define-s and it's not easy for bpf prog to use them. Convert them to enum so bpf prog can take them from vmlinux.h. 2. In the next patch we will add css_task_iter_*() in common kfuncs which is not safe. Since css_task_iter_*() does spin_unlock_irq() which might screw up irq flags depending on the context where bpf prog is running. So we should use irqsave/irqrestore here and the switching is harmless. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20231018061746.111364-2-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-06-28Merge tag 'mm-stable-2023-06-24-19-15' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ...
2023-06-12cgroup: remove unused task_cgroup_path()Miaohe Lin1-1/+0
task_cgroup_path() is not used anymore. So remove it. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-06-09cgroup: remove cgroup_rstat_flush_atomic()Yosry Ahmed1-1/+0
Previous patches removed the only caller of cgroup_rstat_flush_atomic(). Remove the function and simplify the code. Link: https://lkml.kernel.org/r/20230421174020.2994750-6-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic"Yosry Ahmed1-1/+1
Patch series "memcg: avoid flushing stats atomically where possible", v3. rstat flushing is an expensive operation that scales with the number of cpus and the number of cgroups in the system. The purpose of this series is to minimize the contexts where we flush stats atomically. Patches 1 and 2 are cleanups requested during reviews of prior versions of this series. Patch 3 makes sure we never try to flush from within an irq context. Patches 4 to 7 introduce separate variants of mem_cgroup_flush_stats() for atomic and non-atomic flushing, and make sure we only flush the stats atomically when necessary. Patch 8 is a slightly tangential optimization that limits the work done by rstat flushing in some scenarios. This patch (of 8): cgroup_rstat_flush_irqsafe() can be a confusing name. It may read as "irqs are disabled throughout", which is what the current implementation does (currently under discussion [1]), but is not the intention. The intention is that this function is safe to call from atomic contexts. Name it as such. Link: https://lkml.kernel.org/r/20230330191801.1967435-1-yosryahmed@google.com Link: https://lkml.kernel.org/r/20230330191801.1967435-2-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-12Merge tag 'cgroup-for-6.2' of ↵Linus Torvalds1-85/+13
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Nothing too interesting: - Add CONFIG_DEBUG_GROUP_REF which makes cgroup refcnt operations kprobable - A couple cpuset optimizations - Other misc changes including doc and test updates" * tag 'cgroup-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: remove rcu_read_lock()/rcu_read_unlock() in critical section of spin_lock_irq() cgroup/cpuset: Improve cpuset_css_alloc() description kselftest/cgroup: Add cleanup() to test_cpuset_prs.sh cgroup/cpuset: Optimize cpuset_attach() on v2 cgroup/cpuset: Skip spread flags update on v2 kselftest/cgroup: Fix gathering number of CPUs cgroup: cgroup refcnt functions should be exported when CONFIG_DEBUG_CGROUP_REF cgroup: Implement DEBUG_CGROUP_REF
2022-12-08memcg: Fix possible use-after-free in memcg_write_event_control()Tejun Heo1-0/+1
memcg_write_event_control() accesses the dentry->d_name of the specified control fd to route the write call. As a cgroup interface file can't be renamed, it's safe to access d_name as long as the specified file is a regular cgroup file. Also, as these cgroup interface files can't be removed before the directory, it's safe to access the parent too. Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a call to __file_cft() which verified that the specified file is a regular cgroupfs file before further accesses. The cftype pointer returned from __file_cft() was no longer necessary and the commit inadvertently dropped the file type check with it allowing any file to slip through. With the invarients broken, the d_name and parent accesses can now race against renames and removals of arbitrary files and cause use-after-free's. Fix the bug by resurrecting the file type check in __file_cft(). Now that cgroupfs is implemented through kernfs, checking the file operations needs to go through a layer of indirection. Instead, let's check the superblock and dentry type. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft") Cc: stable@kernel.org # v3.14+ Reported-by: Jann Horn <jannh@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-10-31cgroup: cgroup refcnt functions should be exported when CONFIG_DEBUG_CGROUP_REFTejun Heo1-0/+1
6ab428604f72 ("cgroup: Implement DEBUG_CGROUP_REF") added a config option which forces cgroup refcnt functions to be not inlined so that they can be kprobed for debugging. However, it forgot export them when the config is enabled breaking modules which make use of css reference counting. Fix it by adding CGROUP_REF_EXPORT() macro to cgroup_refcnt.h which is defined to EXPORT_SYMBOL_GPL when CONFIG_DEBUG_CGROUP_REF is set. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 6ab428604f72 ("cgroup: Implement DEBUG_CGROUP_REF")
2022-10-28cgroup: Implement DEBUG_CGROUP_REFTejun Heo1-85/+12
It's really difficult to debug when cgroup or css refs leak. Let's add a debug option to force the refcnt function to not be inlined so that they can be kprobed for debugging. Signed-off-by: Tejun Heo <tj@kernel.org>
2022-10-17Merge tag 'cgroup-for-6.1-rc1-fixes' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - Fix a recent regression where a sleeping kernfs function is called with css_set_lock (spinlock) held - Revert the commit to enable cgroup1 support for cgroup_get_from_fd/file() Multiple users assume that the lookup only works for cgroup2 and breaks when fed a cgroup1 file. Instead, introduce a separate set of functions to lookup both v1 and v2 and use them where the user explicitly wants to support both versions. - Compat update for tools/perf/util/bpf_skel/bperf_cgroup.bpf.c. - Add Josef Bacik as a blkcg maintainer. * tag 'cgroup-for-6.1-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: blkcg: Update MAINTAINERS entry mm: cgroup: fix comments for get from fd/file helpers perf stat: Support old kernels for bperf cgroup counting bpf: cgroup_iter: support cgroup1 using cgroup fd cgroup: add cgroup_v1v2_get_from_[fd/file]() Revert "cgroup: enable cgroup_get_from_file() on cgroup1" cgroup: Reorganize css_set_lock and kernfs path processing
2022-10-14Merge tag 'sched-psi-2022-10-14' of ↵Linus Torvalds1-5/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull PSI updates from Ingo Molnar: - Various performance optimizations, resulting in a 4%-9% speedup in the mmtests/config-scheduler-perfpipe micro-benchmark. - New interface to turn PSI on/off on a per cgroup level. * tag 'sched-psi-2022-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/psi: Per-cgroup PSI accounting disable/re-enable interface sched/psi: Cache parent psi_group to speed up group iteration sched/psi: Consolidate cgroup_psi() sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure sched/psi: Remove NR_ONCPU task accounting sched/psi: Optimize task switch inside shared cgroups again sched/psi: Move private helpers to sched/stats.h sched/psi: Save percpu memory when !psi_cgroups_enabled sched/psi: Don't create cgroup PSI files when psi_disabled sched/psi: Fix periodic aggregation shut off
2022-10-11cgroup: add cgroup_v1v2_get_from_[fd/file]()Yosry Ahmed1-0/+1
Add cgroup_v1v2_get_from_fd() and cgroup_v1v2_get_from_file() that support both cgroup1 and cgroup2. Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds1-1/+14
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-10Merge tag 'cgroup-for-6.1' of ↵Linus Torvalds1-10/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - cpuset now support isolated cpus.partition type, which will enable dynamic CPU isolation - pids.peak added to remember the max number of pids used - holes in cgroup namespace plugged - internal cleanups * tag 'cgroup-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (25 commits) cgroup: use strscpy() is more robust and safer iocost_monitor: reorder BlkgIterator cgroup: simplify code in cgroup_apply_control cgroup: Make cgroup_get_from_id() prettier cgroup/cpuset: remove unreachable code cgroup: Remove CFTYPE_PRESSURE cgroup: Improve cftype add/rm error handling kselftest/cgroup: Add cpuset v2 partition root state test cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst cgroup/cpuset: Make partition invalid if cpumask change violates exclusivity rule cgroup/cpuset: Relocate a code block in validate_change() cgroup/cpuset: Show invalid partition reason string cgroup/cpuset: Add a new isolated cpus.partition type cgroup/cpuset: Relax constraints to partition & cpus changes cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective cgroup/cpuset: Miscellaneous cleanups & add helper functions cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset cgroup: add pids.peak interface for pids controller cgroup: Remove data-race around cgrp_dfl_visible cgroup: Fix build failure when CONFIG_SHRINKER_DEBUG ...
2022-09-26mm: multi-gen LRU: kill switchYu Zhao1-1/+14
Add /sys/kernel/mm/lru_gen/enabled as a kill switch. Components that can be disabled include: 0x0001: the multi-gen LRU core 0x0002: walking page table, when arch_has_hw_pte_young() returns true 0x0004: clearing the accessed bit in non-leaf PMD entries, when CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG=y [yYnN]: apply to all the components above E.g., echo y >/sys/kernel/mm/lru_gen/enabled cat /sys/kernel/mm/lru_gen/enabled 0x0007 echo 5 >/sys/kernel/mm/lru_gen/enabled cat /sys/kernel/mm/lru_gen/enabled 0x0005 NB: the page table walks happen on the scale of seconds under heavy memory pressure, in which case the mmap_lock contention is a lesser concern, compared with the LRU lock contention and the I/O congestion. So far the only well-known case of the mmap_lock contention happens on Android, due to Scudo [1] which allocates several thousand VMAs for merely a few hundred MBs. The SPF and the Maple Tree also have provided their own assessments [2][3]. However, if walking page tables does worsen the mmap_lock contention, the kill switch can be used to disable it. In this case the multi-gen LRU will suffer a minor performance degradation, as shown previously. Clearing the accessed bit in non-leaf PMD entries can also be disabled, since this behavior was not tested on x86 varieties other than Intel and AMD. [1] https://source.android.com/devices/tech/debug/scudo [2] https://lore.kernel.org/r/20220128131006.67712-1-michel@lespinasse.org/ [3] https://lore.kernel.org/r/20220426150616.3937571-1-Liam.Howlett@oracle.com/ Link: https://lkml.kernel.org/r/20220918080010.2920238-11-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-12Merge 6.0-rc5 into driver-core-nextGreg Kroah-Hartman1-5/+0
We need the driver core and debugfs changes in this branch. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-09sched/psi: Consolidate cgroup_psi()Chengming Zhou1-5/+0
cgroup_psi() can't return psi_group for root cgroup, so we have many open code "psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi". This patch move cgroup_psi() definition to <linux/psi.h>, in which we can return psi_system for root cgroup, so can handle all cgroups. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20220825164111.29534-9-zhouchengming@bytedance.com
2022-09-09Merge branch 'driver-core/driver-core-next'Peter Zijlstra1-0/+1
Pull in dependent cgroup patches Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-09-01cgroup: Implement cgroup_file_show()Tejun Heo1-0/+1
Add cgroup_file_show() which allows toggling visibility of a cgroup file using the new kernfs_show(). This will be used to hide psi interface files on cgroups where it's disabled. Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220828050440.734579-10-tj@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-26Merge branch 'for-6.0-fixes' into for-6.1Tejun Heo1-5/+0
Pulling to receive 43626dade36f ("group: Add missing cpus_read_lock() to cgroup_attach_task_all()") for a follow-up patch.
2022-08-26cgroup: Homogenize cgroup_get_from_id() return valueMichal Koutný1-5/+0
Cgroup id is user provided datum hence extend its return domain to include possible error reason (similar to cgroup_get_from_fd()). This change also fixes commit d4ccaf58a847 ("bpf: Introduce cgroup iter") that would use NULL instead of proper error handling in d4ccaf58a847 ("bpf: Introduce cgroup iter"). Additionally, neither of: fc_appid_store, bpf_iter_attach_cgroup, mem_cgroup_get_from_ino (callers of cgroup_get_from_fd) is built without CONFIG_CGROUPS (depends via CONFIG_BLK_CGROUP, direct, transitive CONFIG_MEMCG respectively) transitive, so drop the singular definition not needed with !CONFIG_CGROUPS. Fixes: d4ccaf58a847 ("bpf: Introduce cgroup iter") Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-15sched/psi: Remove redundant cgroup_psi() when !CONFIG_CGROUPSHao Jia1-5/+0
cgroup_psi() is only called under CONFIG_CGROUPS. We don't need cgroup_psi() when !CONFIG_CGROUPS, so we can remove it in this case. Signed-off-by: Hao Jia <jiahao.os@bytedance.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-15cgroup: Replace cgroup->ancestor_ids[] with ->ancestors[]Tejun Heo1-5/+3
Every cgroup knows all its ancestors through its ->ancestor_ids[]. There's no advantage to remembering the IDs instead of the pointers directly and this makes the array useless for finding an actual ancestor cgroup forcing cgroup_ancestor() to iteratively walk up the hierarchy instead. Let's replace cgroup->ancestor_ids[] with ->ancestors[] and remove the walking-up from cgroup_ancestor(). While at it, improve comments around cgroup_root->cgrp_ancestor_storage. This patch shouldn't cause user-visible behavior differences. v2: Update cgroup_ancestor() to use ->ancestors[]. v3: cgroup_root->cgrp_ancestor_storage's type is updated to match cgroup->ancestors[]. Better comments. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org>
2022-06-07psi: dont alloc memory for psi by defaultChen Wandun1-1/+1
Memory about struct psi_group is allocated by default for each cgroup even if psi_disabled is true, in this case, these allocated memory is waste, so alloc memory for struct psi_group only when psi_disabled is false. Signed-off-by: Chen Wandun <chenwandun@huawei.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-03-12cgroup: Fix suspicious rcu_dereference_check() usage warningChengming Zhou1-0/+1
task_css_set_check() will use rcu_dereference_check() to check for rcu_read_lock_held() on the read-side, which is not true after commit dc6e0818bc9a ("sched/cpuacct: Optimize away RCU read lock"). This commit drop explicit rcu_read_lock(), change to RCU-sched read-side critical section. So fix the RCU warning by adding check for rcu_read_lock_sched_held(). Fixes: dc6e0818bc9a ("sched/cpuacct: Optimize away RCU read lock") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-by: syzbot+16e3f2c77e7c5a0113f9@syzkaller.appspotmail.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Tested-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20220305034103.57123-1-zhouchengming@bytedance.com
2022-03-01sched/cpuacct: Remove redundant RCU read lockChengming Zhou1-2/+0
The cpuacct_account_field() and it's cgroup v2 wrapper cgroup_account_cputime_field() is only called from cputime in task_group_account_field(), which is already in RCU read-side critical section. So remove these redundant RCU read lock. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220220051426.5274-3-zhouchengming@bytedance.com
2022-03-01sched/cpuacct: Optimize away RCU read lockChengming Zhou1-2/+0
Since cpuacct_charge() is called from the scheduler update_curr(), we must already have rq lock held, then the RCU read lock can be optimized away. And do the same thing in it's wrapper cgroup_account_cputime(), but we can't use lockdep_assert_rq_held() there, which defined in kernel/sched/sched.h. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220220051426.5274-2-zhouchengming@bytedance.com
2021-09-13bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed modeDaniel Borkmann1-21/+1
Fix cgroup v1 interference when non-root cgroup v2 BPF programs are used. Back in the days, commit bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") embedded per-socket cgroup information into sock->sk_cgrp_data and in order to save 8 bytes in struct sock made both mutually exclusive, that is, when cgroup v1 socket tagging (e.g. net_cls/net_prio) is used, then cgroup v2 falls back to the root cgroup in sock_cgroup_ptr() (&cgrp_dfl_root.cgrp). The assumption made was "there is no reason to mix the two and this is in line with how legacy and v2 compatibility is handled" as stated in bd1060a1d671. However, with Kubernetes more widely supporting cgroups v2 as well nowadays, this assumption no longer holds, and the possibility of the v1/v2 mixed mode with the v2 root fallback being hit becomes a real security issue. Many of the cgroup v2 BPF programs are also used for policy enforcement, just to pick _one_ example, that is, to programmatically deny socket related system calls like connect(2) or bind(2). A v2 root fallback would implicitly cause a policy bypass for the affected Pods. In production environments, we have recently seen this case due to various circumstances: i) a different 3rd party agent and/or ii) a container runtime such as [0] in the user's environment configuring legacy cgroup v1 net_cls tags, which triggered implicitly mentioned root fallback. Another case is Kubernetes projects like kind [1] which create Kubernetes nodes in a container and also add cgroup namespaces to the mix, meaning programs which are attached to the cgroup v2 root of the cgroup namespace get attached to a non-root cgroup v2 path from init namespace point of view. And the latter's root is out of reach for agents on a kind Kubernetes node to configure. Meaning, any entity on the node setting cgroup v1 net_cls tag will trigger the bypass despite cgroup v2 BPF programs attached to the namespace root. Generally, this mutual exclusiveness does not hold anymore in today's user environments and makes cgroup v2 usage from BPF side fragile and unreliable. This fix adds proper struct cgroup pointer for the cgroup v2 case to struct sock_cgroup_data in order to address these issues; this implicitly also fixes the tradeoffs being made back then with regards to races and refcount leaks as stated in bd1060a1d671, and removes the fallback, so that cgroup v2 BPF programs always operate as expected. [0] https://github.com/nestybox/sysbox/ [1] https://kind.sigs.k8s.io/ Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Stanislav Fomichev <sdf@google.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/bpf/20210913230759.2313-1-daniel@iogearbox.net
2021-07-02Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds1-0/+6
Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, ibmvfc, megaraid_sas, lpfc, elx, mpi3mr, qedi, iscsi, storvsc, mpt3sas) with elx and mpi3mr being new drivers. The major core change is a rework to drop the status byte handling macros and the old bit shifted definitions and the rest of the updates are minor fixes" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (287 commits) scsi: aha1740: Avoid over-read of sense buffer scsi: arcmsr: Avoid over-read of sense buffer scsi: ips: Avoid over-read of sense buffer scsi: ufs: ufs-mediatek: Add missing of_node_put() in ufs_mtk_probe() scsi: elx: libefc: Fix IRQ restore in efc_domain_dispatch_frame() scsi: elx: libefc: Fix less than zero comparison of a unsigned int scsi: elx: efct: Fix pointer error checking in debugfs init scsi: elx: efct: Fix is_originator return code type scsi: elx: efct: Fix link error for _bad_cmpxchg scsi: elx: efct: Eliminate unnecessary boolean check in efct_hw_command_cancel() scsi: elx: efct: Do not use id uninitialized in efct_lio_setup_session() scsi: elx: efct: Fix error handling in efct_h