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* cgroup: Fix potential overflow issue when checking max_depthXiu Jianfeng2024-10-151-2/+2
| | | | | | | | | | | | | | | | | | | | 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>
* Merge tag 'pull-stable-struct_fd' of ↵Linus Torvalds2024-09-231-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | 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.
| * introduce fd_file(), convert all accessors to it.Al Viro2024-08-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'mm-stable-2024-09-20-02-31' of ↵Linus Torvalds2024-09-211-7/+16
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * | cgroup: clarify css sibling linkage is protected by cgroup_mutex or RCUKinsey Ho2024-09-101-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | mm, memcg: cg2 memory{.swap,}.peak write handlersDavid Finkel2024-09-021-0/+7
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cgroup/cpuset: Expose cpuset filesystem with cpuset v1 onlyMichal Koutný2024-09-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | 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>
* | cgroup: update some statememt about delegationChen Ridong2024-08-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cgroup: Fix incorrect WARN_ON_ONCE() in css_release_work_fn()Waiman Long2024-08-091-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cgroup: Show # of subsystem CSSes in cgroup.statWaiman Long2024-07-311-2/+53
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'for-6.10-fixes' into for-6.11Tejun Heo2024-07-151-1/+1
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| * cgroup: Protect css->cgroup write under css_set_lockWaiman Long2024-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The writing of css->cgroup associated with the cgroup root in rebind_subsystems() is currently protected only by cgroup_mutex. However, the reading of css->cgroup in both proc_cpuset_show() and proc_cgroup_show() is protected just by css_set_lock. That makes the readers susceptible to racing problems like data tearing or caching. It is also a problem that can be reported by KCSAN. This can be fixed by using READ_ONCE() and WRITE_ONCE() to access css->cgroup. Alternatively, the writing of css->cgroup can be moved under css_set_lock as well which is done by this patch. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: avoid the unnecessary list_add(dying_tasks) in cgroup_exit()Oleg Nesterov2024-06-191-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | cgroup_exit() needs to do this only if the exiting task is a leader and it is not the last live thread. The patch doesn't use delay_group_leader(), atomic_read(signal->live) matches the code css_task_iter_advance() more. cgroup_release() can now check list_empty(task->cg_list) before it takes css_set_lock and calls ss_set_skip_task_iters(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | kernel/cgroup: cleanup cgroup_base_files when fail to add cgroup_psi_filesDavid Wang2024-05-261-1/+4
| | | | | | | | | | | | | | | | | | | | | | Even though css_clear_dir would be called to cleanup all existing cgroup files when css_populate_dir failed, reclaiming newly created cgroup files before css_populate_dir returns with failure makes code more consistent. Signed-off-by: David Wang <00107082@163.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup/pids: Separate semantics of pids.events related to pids.maxMichal Koutný2024-05-261-1/+14
|/ | | | | | | | | | | | | | | | | | | | | | | Currently, when pids.max limit is breached in the hierarchy, the event is counted and reported in the cgroup where the forking task resides. This decouples the limit and the notification caused by the limit making it hard to detect when the actual limit was effected. Redefine the pids.events:max as: the number of times the limit of the cgroup was hit. (Implementation differentiates also "forkfail" event but this is currently not exposed as it would better fit into pids.stat. It also differs from pids.events:max only when pids.max is configured on non-leaf cgroups.) Since it changes semantics of the original "max" event, introduce this change only in the v2 API of the controller and add a cgroup2 mount option to revert to the legacy behavior. Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: don't call cgroup1_pidlist_destroy_all() for v2Xiu Jianfeng2024-04-181-1/+2
| | | | | | | | | Currently cgroup1_pidlist_destroy_all() will be called when releasing cgroup even if the cgroup is on default hierarchy, however it doesn't make any sense for v2 to destroy pidlist of v1. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge tag 'driver-core-6.8-rc1' of ↵Linus Torvalds2024-01-181-29/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here are the set of driver core and kernfs changes for 6.8-rc1. Nothing major in here this release cycle, just lots of small cleanups and some tweaks on kernfs that in the very end, got reverted and will come back in a safer way next release cycle. Included in here are: - more driver core 'const' cleanups and fixes - fw_devlink=rpm is now the default behavior - kernfs tiny changes to remove some string functions - cpu handling in the driver core is updated to work better on many systems that add topologies and cpus after booting - other minor changes and cleanups All of the cpu handling patches have been acked by the respective maintainers and are coming in here in one series. Everything has been in linux-next for a while with no reported issues" * tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (51 commits) Revert "kernfs: convert kernfs_idr_lock to an irq safe raw spinlock" kernfs: convert kernfs_idr_lock to an irq safe raw spinlock class: fix use-after-free in class_register() PM: clk: make pm_clk_add_notifier() take a const pointer EDAC: constantify the struct bus_type usage kernfs: fix reference to renamed function driver core: device.h: fix Excess kernel-doc description warning driver core: class: fix Excess kernel-doc description warning driver core: mark remaining local bus_type variables as const driver core: container: make container_subsys const driver core: bus: constantify subsys_register() calls driver core: bus: make bus_sort_breadthfirst() take a const pointer kernfs: d_obtain_alias(NULL) will do the right thing... driver core: Better advertise dev_err_probe() kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy() kernfs: Convert kernfs_name_locked() from strlcpy() to strscpy() kernfs: Convert kernfs_walk_ns() from strlcpy() to strscpy() initramfs: Expose retained initrd as sysfs file fs/kernfs/dir: obey S_ISGID kernel/cgroup: use kernfs_create_dir_ns() ...
| * kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy()Kees Cook2023-12-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the last remaining users of strlcpy() in the kernel is kernfs_path_from_node_locked(), which passes back the problematic "length we _would_ have copied" return value to indicate truncation. Convert the chain of all callers to use the negative return value (some of which already doing this explicitly). All callers were already also checking for negative return values, so the risk to missed checks looks very low. In this analysis, it was found that cgroup1_release_agent() actually didn't handle the "too large" condition, so this is technically also a bug fix. :) Here's the chain of callers, and resolution identifying each one as now handling the correct return value: kernfs_path_from_node_locked() kernfs_path_from_node() pr_cont_kernfs_path() returns void kernfs_path() sysfs_warn_dup() return value ignored cgroup_path() blkg_path() bfq_bic_update_cgroup() return value ignored TRACE_IOCG_PATH() return value ignored TRACE_CGROUP_PATH() return value ignored perf_event_cgroup() return value ignored task_group_path() return value ignored damon_sysfs_memcg_path_eq() return value ignored get_mm_memcg_path() return value ignored lru_gen_seq_show() return value ignored cgroup_path_from_kernfs_id() return value ignored cgroup_show_path() already converted "too large" error to negative value cgroup_path_ns_locked() cgroup_path_ns() bpf_iter_cgroup_show_fdinfo() return value ignored cgroup1_release_agent() wasn't checking "too large" error proc_cgroup_show() already converted "too large" to negative value Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Waiman Long <longman@redhat.com> Cc: <cgroups@vger.kernel.org> Co-developed-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Link: https://lore.kernel.org/r/20231116192127.1558276-3-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20231212211741.164376-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * kernel/cgroup: use kernfs_create_dir_ns()Max Kellermann2023-12-151-27/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By passing the fsugid to kernfs_create_dir_ns(), we don't need cgroup_kn_set_ugid() any longer. That function was added for exactly this purpose by commit 49957f8e2a43 ("cgroup: newly created dirs and files should be owned by the creator"). Eliminating this piece of duplicate code means we benefit from future improvements to kernfs_create_dir_ns(); for example, both are lacking S_ISGID support currently, which my next patch will add to kernfs_create_dir_ns(). It cannot (easily) be added to cgroup_kn_set_ugid() because we can't dereference struct kernfs_iattrs from there. -- v1 -> v2: 12-digit commit id Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20231208093310.297233-1-max.kellermann@ionos.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge tag 'cgroup-for-6.8' of ↵Linus Torvalds2024-01-091-15/+30
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - Yafang Shao added task_get_cgroup1() helper to enable a similar BPF helper so that BPF progs can be more useful on cgroup1 hierarchies. While cgroup1 is mostly in maintenance mode, this addition is very small while having an outsized usefulness for users who are still on cgroup1. Yafang also optimized root cgroup list access by making it RCU protected in the process. - Waiman Long optimized rstat operation leading to substantially lower and more consistent lock hold time while flushing the hierarchical statistics. As the lock can be acquired briefly in various hot paths, this reduction has cascading benefits. - Waiman also improved the quality of isolation for cpuset's isolated partitions. CPUs which are allocated to isolated partitions are now excluded from running unbound work items and cpu_is_isolated() test which is used by vmstat and memcg to reduce interference now includes cpuset isolated CPUs. While it isn't there yet, the hope is eventually reaching parity with the isolation level provided by the `isolcpus` boot param but in a dynamic manner. * tag 'cgroup-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Move rcu_head up near the top of cgroup_root cgroup/cpuset: Include isolated cpuset CPUs in cpu_is_isolated() check cgroup: Avoid false cacheline sharing of read mostly rstat_cpu cgroup/rstat: Optimize cgroup_rstat_updated_list() cgroup: Fix documentation for cpu.idle cgroup/cpuset: Expose cpuset.cpus.isolated workqueue: Move workqueue_set_unbound_cpumask() and its helpers inside CONFIG_SYSFS cgroup/rstat: Reduce cpu_lock hold time in cgroup_rstat_flush_locked() cgroup/cpuset: Take isolated CPUs out of workqueue unbound cpumask cgroup/cpuset: Keep track of CPUs in isolated partitions selftests/cgroup: Minor code cleanup and reorganization of test_cpuset_prs.sh workqueue: Add workqueue_unbound_exclude_cpumask() to exclude CPUs from wq_unbound_cpumask selftests: cgroup: Fixes a typo in a comment cgroup: Add a new helper for cgroup1 hierarchy cgroup: Add annotation for holding namespace_sem in current_cgns_cgroup_from_root() cgroup: Eliminate the need for cgroup_mutex in proc_cgroup_show() cgroup: Make operations on the cgroup root_list RCU safe cgroup: Remove unnecessary list_empty()
| * cgroup: Add annotation for holding namespace_sem in ↵Yafang Shao2023-11-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | current_cgns_cgroup_from_root() When I initially examined the function current_cgns_cgroup_from_root(), I was perplexed by its lack of holding cgroup_mutex. However, after Michal explained the reason[0] to me, I realized that it already holds the namespace_sem. I believe this intricacy could also confuse others, so it would be advisable to include an annotation for clarification. After we replace the cgroup_mutex with RCU read lock, if current doesn't hold the namespace_sem, the root cgroup will be NULL. So let's add a WARN_ON_ONCE() for it. [0]. https://lore.kernel.org/bpf/afdnpo3jz2ic2ampud7swd6so5carkilts2mkygcaw67vbw6yh@5b5mncf7qyet Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: Michal Koutny <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: Eliminate the need for cgroup_mutex in proc_cgroup_show()Yafang Shao2023-11-101-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cgroup root_list is already RCU-safe. Therefore, we can replace the cgroup_mutex with the RCU read lock in some particular paths. This change will be particularly beneficial for frequent operations, such as `cat /proc/self/cgroup`, in a cgroup1-based container environment. I did stress tests with this change, as outlined below (with CONFIG_PROVE_RCU_LIST enabled): - Continuously mounting and unmounting named cgroups in some tasks, for example: cgrp_name=$1 while true do mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name umount /$cgrp_name done - Continuously triggering proc_cgroup_show() in some tasks concurrently, for example: while true; do cat /proc/self/cgroup > /dev/null; done They can ran successfully after implementing this change, with no RCU warnings in dmesg. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: Make operations on the cgroup root_list RCU safeYafang Shao2023-11-101-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | At present, when we perform operations on the cgroup root_list, we must hold the cgroup_mutex, which is a relatively heavyweight lock. In reality, we can make operations on this list RCU-safe, eliminating the need to hold the cgroup_mutex during traversal. Modifications to the list only occur in the cgroup root setup and destroy paths, which should be infrequent in a production environment. In contrast, traversal may occur frequently. Therefore, making it RCU-safe would be beneficial. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: Remove unnecessary list_empty()Yafang Shao2023-11-101-4/+3
| | | | | | | | | | | | | | | | | | The root hasn't been removed from the root_list, so the list can't be NULL. However, if it had been removed, attempting to destroy it once more is not possible. Let's replace this with WARN_ON_ONCE() for clarity. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | sched: psi: fix unprivileged polling against cgroupsJohannes Weiner2023-11-141-12/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 519fabc7aaba ("psi: remove 500ms min window size limitation for triggers") breaks unprivileged psi polling on cgroups. Historically, we had a privilege check for polling in the open() of a pressure file in /proc, but were erroneously missing it for the open() of cgroup pressure files. When unprivileged polling was introduced in d82caa273565 ("sched/psi: Allow unprivileged polling of N*2s period"), it needed to filter privileges depending on the exact polling parameters, and as such moved the CAP_SYS_RESOURCE check from the proc open() callback to psi_trigger_create(). Both the proc files as well as cgroup files go through this during write(). This implicitly added the missing check for privileges required for HT polling for cgroups. When 519fabc7aaba ("psi: remove 500ms min window size limitation for triggers") followed right after to remove further restrictions on the RT polling window, it incorrectly assumed the cgroup privilege check was still missing and added it to the cgroup open(), mirroring what we used to do for proc files in the past. As a result, unprivileged poll requests that would be supported now get rejected when opening the cgroup pressure file for writing. Remove the cgroup open() check. psi_trigger_create() handles it. Fixes: 519fabc7aaba ("psi: remove 500ms min window size limitation for triggers") Reported-by: Luca Boccassi <bluca@debian.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Luca Boccassi <bluca@debian.org> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: stable@vger.kernel.org # 6.5+ Link: https://lore.kernel.org/r/20231026164114.2488682-1-hannes@cmpxchg.org
* Merge tag 'mm-stable-2023-11-01-14-33' of ↵Linus Torvalds2023-11-031-1/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Kemeng Shi has contributed some compation maintenance work in the series 'Fixes and cleanups to compaction' - Joel Fernandes has a patchset ('Optimize mremap during mutual alignment within PMD') which fixes an obscure issue with mremap()'s pagetable handling during a subsequent exec(), based upon an implementation which Linus suggested - More DAMON/DAMOS maintenance and feature work from SeongJae Park i the following patch series: mm/damon: misc fixups for documents, comments and its tracepoint mm/damon: add a tracepoint for damos apply target regions mm/damon: provide pseudo-moving sum based access rate mm/damon: implement DAMOS apply intervals mm/damon/core-test: Fix memory leaks in core-test mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval - In the series 'Do not try to access unaccepted memory' Adrian Hunter provides some fixups for the recently-added 'unaccepted memory' feature. To increase the feature's checking coverage. 'Plug a few gaps where RAM is exposed without checking if it is unaccepted memory' - In the series 'cleanups for lockless slab shrink' Qi Zheng has done some maintenance work which is preparation for the lockless slab shrinking code - Qi Zheng has redone the earlier (and reverted) attempt to make slab shrinking lockless in the series 'use refcount+RCU method to implement lockless slab shrink' - David Hildenbrand contributes some maintenance work for the rmap code in the series 'Anon rmap cleanups' - Kefeng Wang does more folio conversions and some maintenance work in the migration code. Series 'mm: migrate: more folio conversion and unification' - Matthew Wilcox has fixed an issue in the buffer_head code which was causing long stalls under some heavy memory/IO loads. Some cleanups were added on the way. Series 'Add and use bdev_getblk()' - In the series 'Use nth_page() in place of direct struct page manipulation' Zi Yan has fixed a potential issue with the direct manipulation of hugetlb page frames - In the series 'mm: hugetlb: Skip initialization of gigantic tail struct pages if freed by HVO' has improved our handling of gigantic pages in the hugetlb vmmemmep optimizaton code. This provides significant boot time improvements when significant amounts of gigantic pages are in use - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code rationalization and folio conversions in the hugetlb code - Yin Fengwei has improved mlock()'s handling of large folios in the series 'support large folio for mlock' - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has added statistics for memcg v1 users which are available (and useful) under memcg v2 - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable) prctl so that userspace may direct the kernel to not automatically propagate the denial to child processes. The series is named 'MDWE without inheritance' - Kefeng Wang has provided the series 'mm: convert numa balancing functions to use a folio' which does what it says - In the series 'mm/ksm: add fork-exec support for prctl' Stefan Roesch makes is possible for a process to propagate KSM treatment across exec() - Huang Ying has enhanced memory tiering's calculation of memory distances. This is used to permit the dax/kmem driver to use 'high bandwidth memory' in addition to Optane Data Center Persistent Memory Modules (DCPMM). The series is named 'memory tiering: calculate abstract distance based on ACPI HMAT' - In the series 'Smart scanning mode for KSM' Stefan Roesch has optimized KSM by teaching it to retain and use some historical information from previous scans - Yosry Ahmed has fixed some inconsistencies in memcg statistics in the series 'mm: memcg: fix tracking of pending stats updates values' - In the series 'Implement IOCTL to get and optionally clear info about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap which permits us to atomically read-then-clear page softdirty state. This is mainly used by CRIU - Hugh Dickins contributed the series 'shmem,tmpfs: general maintenance', a bunch of relatively minor maintenance tweaks to this code - Matthew Wilcox has increased the use of the VMA lock over file-backed page faults in the series 'Handle more faults under the VMA lock'. Some rationalizations of the fault path became possible as a result - In the series 'mm/rmap: convert page_move_anon_rmap() to folio_move_anon_rmap()' David Hildenbrand has implemented some cleanups and folio conversions - In the series 'various improvements to the GUP interface' Lorenzo Stoakes has simplified and improved the GUP interface with an eye to providing groundwork for future improvements - Andrey Konovalov has sent along the series 'kasan: assorted fixes and improvements' which does those things - Some page allocator maintenance work from Kemeng Shi in the series 'Two minor cleanups to break_down_buddy_pages' - In thes series 'New selftest for mm' Breno Leitao has developed another MM self test which tickles a race we had between madvise() and page faults - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups and an optimization to the core pagecache code - Nhat Pham has added memcg accounting for hugetlb memory in the series 'hugetlb memcg accounting' - Cleanups and rationalizations to the pagemap code from Lorenzo Stoakes, in the series 'Abstract vma_merge() and split_vma()' - Audra Mitchell has fixed issues in the procfs page_owner code's new timestamping feature which was causing some misbehaviours. In the series 'Fix page_owner's use of free timestamps' - Lorenzo Stoakes has fixed the handling of new mappings of sealed files in the series 'permit write-sealed memfd read-only shared mappings' - Mike Kravetz has optimized the hugetlb vmemmap optimization in the series 'Batch hugetlb vmemmap modification operations' - Some buffer_head folio conversions and cleanups from Matthew Wilcox in the series 'Finish the create_empty_buffers() transition' - As a page allocator performance optimization Huang Ying has added automatic tuning to the allocator's per-cpu-pages feature, in the series 'mm: PCP high auto-tuning' - Roman Gushchin has contributed the patchset 'mm: improve performance of accounted kernel memory allocations' which improves their performance by ~30% as measured by a micro-benchmark - folio conversions from Kefeng Wang in the series 'mm: convert page cpupid functions to folios' - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about kmemleak' - Qi Zheng has improved our handling of memoryless nodes by keeping them off the allocation fallback list. This is done in the series 'handle memoryless nodes more appropriately' - khugepaged conversions from Vishal Moola in the series 'Some khugepaged folio conversions'" [ bcachefs conflicts with the dynamically allocated shrinkers have been resolved as per Stephen Rothwell in https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/ with help from Qi Zheng. The clone3 test filtering conflict was half-arsed by yours truly ] * tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits) mm/damon/sysfs: update monitoring target regions for online input commit mm/damon/sysfs: remove requested targets when online-commit inputs selftests: add a sanity check for zswap Documentation: maple_tree: fix word spelling error mm/vmalloc: fix the unchecked dereference warning in vread_iter() zswap: export compression failure stats Documentation: ubsan: drop "the" from article title mempolicy: migration attempt to match interleave nodes mempolicy: mmap_lock is not needed while migrating folios mempolicy: alloc_pages_mpol() for NUMA policy without vma mm: add page_rmappable_folio() wrapper mempolicy: remove confusing MPOL_MF_LAZY dead code mempolicy: mpol_shared_policy_init() without pseudo-vma mempolicy trivia: use pgoff_t in shared mempolicy tree mempolicy trivia: slightly more consistent naming mempolicy trivia: delete those ancient pr_debug()s mempolicy: fix migrate_pages(2) syscall return nr_failed kernfs: drop shared NUMA mempolicy hooks hugetlbfs: drop shared NUMA mempolicy pretence mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets() ...
| * hugetlb: memcg: account hugetlb-backed memory in memory controllerNhat Pham2023-10-181-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, hugetlb memory usage is not acounted for in the memory controller, which could lead to memory overprotection for cgroups with hugetlb-backed memory. This has been observed in our production system. For instance, here is one of our usecases: suppose there are two 32G containers. The machine is booted with hugetlb_cma=6G, and each container may or may not use up to 3 gigantic page, depending on the workload within it. The rest is anon, cache, slab, etc. We can set the hugetlb cgroup limit of each cgroup to 3G to enforce hugetlb fairness. But it is very difficult to configure memory.max to keep overall consumption, including anon, cache, slab etc. fair. What we have had to resort to is to constantly poll hugetlb usage and readjust memory.max. Similar procedure is done to other memory limits (memory.low for e.g). However, this is rather cumbersome and buggy. Furthermore, when there is a delay in memory limits correction, (for e.g when hugetlb usage changes within consecutive runs of the userspace agent), the system could be in an over/underprotected state. This patch rectifies this issue by charging the memcg when the hugetlb folio is utilized, and uncharging when the folio is freed (analogous to the hugetlb controller). Note that we do not charge when the folio is allocated to the hugetlb pool, because at this point it is not owned by any memcg. Some caveats to consider: * This feature is only available on cgroup v2. * There is no hugetlb pool management involved in the memory controller. As stated above, hugetlb folios are only charged towards the memory controller when it is used. Host overcommit management has to consider it when configuring hard limits. * Failure to charge towards the memcg results in SIGBUS. This could happen even if the hugetlb pool still has pages (but the cgroup limit is hit and reclaim attempt fails). * When this feature is enabled, hugetlb pages contribute to memory reclaim protection. low, min limits tuning must take into account hugetlb memory. * Hugetlb pages utilized while this option is not selected will not be tracked by the memory controller (even if cgroup v2 is remounted later on). Link: https://lkml.kernel.org/r/20231006184629.155543-4-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Frank van der Linden <fvdl@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun heo <tj@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'net-next-6.7' of ↵Linus Torvalds2023-10-311-6/+12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core & protocols: - Support usec resolution of TCP timestamps, enabled selectively by a route attribute. - Defer regular TCP ACK while processing socket backlog, try to send a cumulative ACK at the end. Increase single TCP flow performance on a 200Gbit NIC by 20% (100Gbit -> 120Gbit). - The Fair Queuing (FQ) packet scheduler: - add built-in 3 band prio / WRR scheduling - support bypass if the qdisc is mostly idle (5% speed up for TCP RR) - improve inactive flow reporting - optimize the layout of structures for better cache locality - Support TCP Authentication Option (RFC 5925, TCP-AO), a more modern replacement for the old MD5 option. - Add more retransmission timeout (RTO) related statistics to TCP_INFO. - Support sending fragmented skbs over vsock sockets. - Make sure we send SIGPIPE for vsock sockets if socket was shutdown(). - Add sysctl for ignoring lower limit on lifetime in Router Advertisement PIO, based on an in-progress IETF draft. - Add sysctl to control activation of TCP ping-pong mode. - Add sysctl to make connection timeout in MPTCP configurable. - Support rcvlowat and notsent_lowat on MPTCP sockets, to help apps limit the number of wakeups. - Support netlink GET for MDB (multicast forwarding), allowing user space to request a single MDB entry instead of dumping the entire table. - Support selective FDB flushing in the VXLAN tunnel driver. - Allow limiting learned FDB entries in bridges, prevent OOM attacks. - Allow controlling via configfs netconsole targets which were created via the kernel cmdline at boot, rather than via configfs at runtime. - Support multiple PTP timestamp event queue readers with different filters. - MCTP over I3C. BPF: - Add new veth-like netdevice where BPF program defines the logic of the xmit routine. It can operate in L3 and L2 mode. - Support exceptions - allow asserting conditions which should never be true but are hard for the verifier to infer. With some extra flexibility around handling of the exit / failure: https://lwn.net/Articles/938435/ - Add support for local per-cpu kptr, allow allocating and storing per-cpu objects in maps. Access to those objects operates on the value for the current CPU. This allows to deprecate local one-off implementations of per-CPU storage like BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE maps. - Extend cgroup BPF sockaddr hooks for UNIX sockets. The use case is for systemd to re-implement the LogNamespace feature which allows running multiple instances of systemd-journald to process the logs of different services. - Enable open-coded task_vma iteration, after maple tree conversion made it hard to directly walk VMAs in tracing programs. - Add open-coded task, css_task and css iterator support. One of the use cases is customizable OOM victim selection via BPF. - Allow source address selection with bpf_*_fib_lookup(). - Add ability to pin BPF timer to the current CPU. - Prevent creation of infinite loops by combining tail calls and fentry/fexit programs. - Add missed stats for kprobes to retrieve the number of missed kprobe executions and subsequent executions of BPF programs. - Inherit system settings for CPU security mitigations. - Add BPF v4 CPU instruction support for arm32 and s390x. Changes to common code: - overflow: add DEFINE_FLEX() for on-stack definition of structs with flexible array members. - Process doc update with more guidance for reviewers. Driver API: - Simplify locking in WiFi (cfg80211 and mac80211 layers), use wiphy mutex in most places and remove a lot of smaller locks. - Create a common DPLL configuration API. Allow configuring and querying state of PLL circuits used for clock syntonization, in network time distribution. - Unify fragmented and full page allocation APIs in page pool code. Let drivers be ignorant of PAGE_SIZE. - Rework PHY state machine to avoid races with calls to phy_stop(). - Notify DSA drivers of MAC address changes on user ports, improve correctness of offloads which depend on matching port MAC addresses. - Allow antenna control on injected WiFi frames. - Reduce the number of variants of napi_schedule(). - Simplify error handling when composing devlink health messages. Misc: - A lot of KCSAN data race "fixes", from Eric. - A lot of __counted_by() annotations, from Kees. - A lot of strncpy -> strscpy and printf format fixes. - Replace master/slave terminology with conduit/user in DSA drivers. - Handful of KUnit tests for netdev and WiFi core. Removed: - AppleTalk COPS. - AppleTalk ipddp. - TI AR7 CPMAC Ethernet driver. Drivers: - Ethernet high-speed NICs: - Intel (100G, ice, idpf): - add a driver for the Intel E2000 IPUs - make CRC/FCS stripping configurable - cross-timestamping for E823 devices - basic support for E830 devices - use aux-bus for managing client drivers - i40e: report firmware versions via devlink - nVidia/Mellanox: - support 4-port NICs - increase max number of channels to 256 - optimize / parallelize SF creation flow - Broadcom (bnxt): - enhance NIC temperature reporting - support PAM4 speeds and lane configuration - Marvell OcteonTX2: - PTP pulse-per-second output support - enable hardware timestamping for VFs - Solarflare/AMD: - conntrack NAT offload and offload for tunnels - Wangxun (ngbe/txgbe): - expose HW statistics - Pensando/AMD: - support PCI level reset - narrow down the condition under which skbs are linearized - Netronome/Corigine (nfp): - support CHACHA20-POLY1305 crypto in IPsec offload - Ethernet NICs embedded, slower, virtual: - Synopsys (stmmac): - add Loongson-1 SoC support - enable use of HW queues with no offload capabilities - enable PPS input support on all 5 channels - increase TX coalesce timer to 5ms - RealTek USB (r8152): improve efficiency of Rx by using GRO frags - xen: support SW packet timestamping - add drivers for implementations based on TI's PRUSS (AM64x EVM) - nVidia/Mellanox Ethernet datacenter switches: - avoid poor HW resource use on Spectrum-4 by better block selection for IPv6 multicast forwarding and ordering of blocks in ACL region - Ethernet embedded switches: - Microchip: - support configuring the drive strength for EMI compliance - ksz9477: partial ACL support - ksz9477: HSR offload - ksz9477: Wake on LAN - Realtek: - rtl8366rb: respect device tree config of the CPU port - Ethernet PHYs: - support Broadcom BCM5221 PHYs - TI dp83867: support hardware LED blinking - CAN: - add support for Linux-PHY based CAN transceivers - at91_can: clean up and use rx-offload helpers - WiFi: - MediaTek (mt76): - new sub-driver for mt7925 USB/PCIe devices - HW wireless <> Ethernet bridging in MT7988 chips - mt7603/mt7628 stability improvements - Qualcomm (ath12k): - WCN7850: - enable 320 MHz channels in 6 GHz band - hardware rfkill support - enable IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS to make scan faster - read board data variant name from SMBIOS - QCN9274: mesh support - RealTek (rtw89): - TDMA-based multi-channel concurrency (MCC) - Silicon Labs (wfx): - Remain-On-Channel (ROC) support - Bluetooth: - ISO: many improvements for broadcast support - mark BCM4378/BCM4387 as BROKEN_LE_CODED - add support for QCA2066 - btmtksdio: enable Bluetooth wakeup from suspend" * tag 'net-next-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1816 commits) net: pcs: xpcs: Add 2500BASE-X case in get state for XPCS drivers net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos() net: mana: Use xdp_set_features_flag instead of direct assignment vxlan: Cleanup IFLA_VXLAN_PORT_RANGE entry in vxlan_get_size() iavf: delete the iavf client interface iavf: add a common function for undoing the interrupt scheme iavf: use unregister_netdev iavf: rely on netdev's own registered state iavf: fix the waiting time for initial reset iavf: in iavf_down, don't queue watchdog_task if comms failed iavf: simplify mutex_trylock+sleep loops iavf: fix comments about old bit locks doc/netlink: Update schema to support cmd-cnt-name and cmd-max-name tools: ynl: introduce option to process unknown attributes or types ipvlan: properly track tx_errors netdevsim: Block until all devices are released nfp: using napi_build_skb() to replace build_skb() net: dsa: microchip: ksz9477: Fix spelling mistake "Enery" -> "Energy" net: dsa: microchip: Ensure Stable PME Pin State for Wake-on-LAN net: dsa: microchip: Refactor switch shutdown routine for WoL preparation ...
| * | cgroup: Prepare for using css_task_iter_*() in BPFChuyi Zhou2023-10-201-6/+12
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cgroup: use legacy_name for cgroup v1 disable infoKamalesh Babulal2023-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup v1 or v2 or both controller names can be passed as arguments to the 'cgroup_no_v1' kernel parameter, though most of the controller's names are the same for both cgroup versions. This can be confusing when both versions are used interchangeably, i.e., passing cgroup_no_v1=io $ sudo dmesg |grep cgroup ... cgroup: Disabling io control group subsystem in v1 mounts cgroup: Disabled controller 'blkio' Make it consistent across the pr_info()'s, by using ss->legacy_name, as the subsystem name, while printing the cgroup v1 controller disabling information in cgroup_init(). Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: add cgroup_favordynmods= command-line optionLuiz Capitulino2023-10-041-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have a need of using favordynmods with cgroup v1, which doesn't support changing mount flags during remount. Enabling CONFIG_CGROUP_FAVOR_DYNMODS at build-time is not an option because we want to be able to selectively enable it for certain systems. This commit addresses this by introducing the cgroup_favordynmods= command-line option. This option works for both cgroup v1 and v2 and also allows for disabling favorynmods when the kernel built with CONFIG_CGROUP_FAVOR_DYNMODS=y. Also, note that when cgroup_favordynmods=true favordynmods is never disabled in cgroup_destroy_root(). Signed-off-by: Luiz Capitulino <luizcap@amazon.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: Avoid extra dereference in css_populate_dir()Kamalesh Babulal2023-09-181-2/+2
| | | | | | | | | | | | | | | | | | | | Use css directly instead of dereferencing it from &cgroup->self, while adding the cgroup v2 cft base and psi files in css_populate_dir(). Both points to the same css, when css->ss is NULL, this avoids extra deferences and makes code consistent in usage across the function. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: Check for ret during cgroup1_base_files cft additionKamalesh Babulal2023-09-181-2/+4
|/ | | | | | | | | | There is no check for possible failure while populating cgroup1_base_files cft in css_populate_dir(), like its cgroup v2 counter parts cgroup_{base,psi}_files. In case of failure, the cgroup might not be set up right. Add ret value check to return on failure. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: fix build when CGROUP_SCHED is not enabledLinus Torvalds2023-09-021-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Sudip Mukherjee reports that the mips sb1250_swarm_defconfig build fails with the current kernel. It isn't actually MIPS-specific, it's just that that defconfig does not have CGROUP_SCHED enabled like most configs do, and as such shows this error: kernel/cgroup/cgroup.c: In function 'cgroup_local_stat_show': kernel/cgroup/cgroup.c:3699:15: error: implicit declaration of function 'cgroup_tryget_css'; did you mean 'cgroup_tryget'? [-Werror=implicit-function-declaration] 3699 | css = cgroup_tryget_css(cgrp, ss); | ^~~~~~~~~~~~~~~~~ | cgroup_tryget kernel/cgroup/cgroup.c:3699:13: warning: assignment to 'struct cgroup_subsys_state *' from 'int' makes pointer from integer without a cast [-Wint-conversion] 3699 | css = cgroup_tryget_css(cgrp, ss); | ^ because cgroup_tryget_css() only exists when CGROUP_SCHED is enabled, and the cgroup_local_stat_show() function should similarly be guarded by that config option. Move things around a bit to fix this all. Fixes: d1d4ff5d11a5 ("cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED") Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'cgroup-for-6.6' of ↵Linus Torvalds2023-09-021-44/+41
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - Per-cpu cpu usage stats are now tracked This currently isn't printed out in the cgroupfs interface and can only be accessed through e.g. BPF. Should decide on a not-too-ugly way to show per-cpu stats in cgroupfs - cpuset received some cleanups and prepatory patches for the pending cpus.exclusive patchset which will allow cpuset partitions to be created below non-partition parents, which should ease the management of partition cpusets - A lot of code and documentation cleanup patches - tools/testing/selftests/cgroup/test_cpuset.c added * tag 'cgroup-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (32 commits) cgroup: Avoid -Wstringop-overflow warnings cgroup:namespace: Remove unused cgroup_namespaces_init() cgroup/rstat: Record the cumulative per-cpu time of cgroup and its descendants cgroup: clean up if condition in cgroup_pidlist_start() cgroup: fix obsolete function name in cgroup_destroy_locked() Documentation: cgroup-v2.rst: Correct number of stats entries cgroup: fix obsolete function name above css_free_rwork_fn() cgroup/cpuset: fix kernel-doc cgroup: clean up printk() cgroup: fix obsolete comment above cgroup_create() docs: cgroup-v1: fix typo docs: cgroup-v1: correct the term of Page Cache organization in inode cgroup/misc: Store atomic64_t reads to u64 cgroup/misc: Change counters to be explicit 64bit types cgroup/misc: update struct members descriptions cgroup: remove cgrp->kn check in css_populate_dir() cgroup: fix obsolete function name cgroup: use cached local variable parent in for loop cgroup: remove obsolete comment above struct cgroupstats cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED ...
| * cgroup: Avoid -Wstringop-overflow warningsGustavo A. R. Silva2023-08-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the notation from pointer-to-array to pointer-to-pointer. With this, we avoid the compiler complaining about trying to access a region of size zero as an argument during function calls. This is a workaround to prevent the compiler complaining about accessing an array of size zero when evaluating the arguments of a couple of function calls. See below: kernel/cgroup/cgroup.c: In function 'find_css_set': kernel/cgroup/cgroup.c:1206:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] 1206 | cset = find_existing_css_set(old_cset, cgrp, template); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/cgroup/cgroup.c:1206:16: note: referencing argument 3 of type 'struct cgroup_subsys_state *[0]' kernel/cgroup/cgroup.c:1071:24: note: in a call to function 'find_existing_css_set' 1071 | static struct css_set *find_existing_css_set(struct css_set *old_cset, | ^~~~~~~~~~~~~~~~~~~~~ With the change to pointer-to-pointer, the functions are not prevented from being executed, and they will do what they have to do when CGROUP_SUBSYS_COUNT == 0. Address the following -Wstringop-overflow warnings seen when built with ARM architecture and aspeed_g4_defconfig configuration (notice that under this configuration CGROUP_SUBSYS_COUNT == 0): kernel/cgroup/cgroup.c:1208:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] kernel/cgroup/cgroup.c:1258:15: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] kernel/cgroup/cgroup.c:6089:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] kernel/cgroup/cgroup.c:6153:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] This results in no differences in binary output. Link: https://github.com/KSPP/linux/issues/316 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: fix obsolete function name in cgroup_destroy_locked()Miaohe Lin2023-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | Since commit e76ecaeef65c ("cgroup: use cgroup_kn_lock_live() in other cgroup kernfs methods"), cgroup_kn_lock_live() is used in cgroup kernfs methods. Update corresponding comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: fix obsolete function name above css_free_rwork_fn()Miaohe Lin2023-08-021-1/+1
| | | | | | | | | | | | | | | | | | Since commit 8f36aaec9c92 ("cgroup: Use rcu_work instead of explicit rcu and work item"), css_free_work_fn has been renamed to css_free_rwork_fn. Update corresponding comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: clean up printk()Kamalesh Babulal2023-08-021-2/+2
| | | | | | | | | | | | | | Convert the only printk() to use pr_*() helper. No functional change. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: fix obsolete comment above cgroup_create()Miaohe Lin2023-07-211-2/+1
| | | | | | | | | | | | | | | | Since commit 743210386c03 ("cgroup: use cgrp->kn->id as the cgroup ID"), cgrp is associated with its kernfs_node. Update corresponding comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: remove cgrp->kn check in css_populate_dir()Kamalesh Babulal2023-07-171-1/+1
| | | | | | | | | | | | | | | | | | | | cgroup_create() creates cgrp and assigns the kernfs_node to cgrp->kn, then cgroup_mkdir() populates base and csses cft file by calling css_populate_dir() and cgroup_apply_control_enable() with a valid cgrp->kn. Check for NULL cgrp->kn, will always be false, remove it. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: fix obsolete function nameMiaohe Lin2023-07-171-1/+1
| | | | | | | | | | | | | | | | | | cgroup_taskset_migrate() has been renamed to cgroup_migrate_execute() since commit e595cd706982 ("cgroup: track migration context in cgroup_mgctx"). Update the corresponding comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: use cached local variable parent in for loopMiaohe Lin2023-07-171-1/+1
| | | | | | | | | | | | | | | | Use local variable parent to initialize iter tcgrp in for loop so the size of cgroup.o can be reduced by 64 bytes. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHEDMiaohe Lin2023-07-111-22/+22
| | | | | | | | | | | | | | | | | | | | Put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED to fix the warning of 'cgroup_tryget_css' defined but not used [-Wunused-function] when CONFIG_CGROUP_SCHED is disabled. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: fix obsolete comment above for_each_css()Miaohe Lin2023-07-101-1/+1
| | | | | | | | | | | | | | | | cgroup_tree_mutex is removed since commit 8353da1f91f1 ("cgroup: remove cgroup_tree_mutex"), update corresponding comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: minor cleanup for cgroup_extra_stat_show()Miaohe Lin2023-07-101-4/+5
| | | | | | | | | | | | | | | | | | Make it under CONFIG_CGROUP_SCHED to rid of __maybe_unused annotation. And further fetch cgrp inside cgroup_extra_stat_show() directly to rid of __maybe_unused annotation of cgrp. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: remove unneeded return value of cgroup_rm_cftypes_locked()Miaohe Lin2023-07-101-6/+3
| | | | | | | | | | | | | | | | | | The return value of cgroup_rm_cftypes_locked() is always 0. So remove it to simplify the code. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | Merge tag 'v6.5-rc2' into sched/core, to pick up fixesIngo Molnar2023-07-191-1/+1
|\ \ | | | | | | | | | | | | | | | Sync with upstream fixes before applying EEVDF. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/psi: use kernfs polling functions for PSI trigger pollingSuren Baghdasaryan2023-07-101-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Destroying psi trigger in cgroup_file_release causes UAF issues when a cgroup is removed from under a polling process. This is happening because cgroup removal causes a call to cgroup_file_release while the actual file is still alive. Destroying the trigger at this point would also destroy its waitqueue head and if there is still a polling process on that file accessing the waitqueue, it will step on the freed pointer: do_select vfs_poll do_rmdir cgroup_rmdir kernfs_drain_open_files cgroup_file_release cgroup_pressure_release psi_trigger_destroy wake_up_pollfree(&t->event_wait) // vfs_poll is unblocked synchronize_rcu kfree(t) poll_freewait -> UAF access to the trigger's waitqueue head Patch [1] fixed this issue for epoll() case using wake_up_pollfree(), however the same issue exists for synchronous poll() case. The root cause of this issue is that the lifecycles of the psi trigger's waitqueue and of the file associated with the trigger are different. Fix this by using kernfs_generic_poll function when polling on cgroup-specific psi triggers. It internally uses kernfs_open_node->poll waitqueue head with its lifecycle tied to the file's lifecycle. This also renders the fix in [1] obsolete, so revert it. [1] commit c2dbe32d5db5 ("sched/psi: Fix use-after-free in ep_remove_wait_queue()") Fixes: 0e94682b73bf ("psi: introduce psi monitor") Closes: https://lore.kernel.org/all/20230613062306.101831-1-lujialin4@huawei.com/ Reported-by: Lu Jialin <lujialin4@huawei.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230630005612.1014540-1-surenb@google.com
* / sched: add throttled time stat for throttled childrenJosh Don2023-07-131-0/+34
|/ | | | | | | | | | | | | | | | | | | We currently export the total throttled time for cgroups that are given a bandwidth limit. This patch extends this accounting to also account the total time that each children cgroup has been throttled. This is useful to understand the degree to which children have been affected by the throttling control. Children which are not runnable during the entire throttled period, for example, will not show any self-throttling time during this period. Expose this in a new interface, 'cpu.stat.local', which is similar to how non-hierarchical events are accounted in 'memory.events.local'. Signed-off-by: Josh Don <joshdon@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230620183247.737942-2-joshdon@google.com