kernel/linux.git/Documentation/admin-guide/cgroup-v1, branch v6.6.148

mm, memcg: reconsider kmem.limit_in_bytes deprecation

2023-09-30T00:20:47+00:00

This reverts commits 86327e8eb94c ("memcg: drop kmem.limit_in_bytes") and partially reverts 58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes") which have incrementally removed support for the kernel memory accounting hard limit. Unfortunately it has turned out that there is still userspace depending on the existence of memory.kmem.limit_in_bytes [1]. The underlying functionality is not really required but the non-existent file just confuses the userspace which fails in the result. The patch to fix this on the userspace side has been submitted but it is hard to predict how it will propagate through the maze of 3rd party consumers of the software. Now, reverting alone 86327e8eb94c is not an option because there is another set of userspace which cannot cope with ENOTSUPP returned when writing to the file. Therefore we have to go and revisit 58056f77502f as well. There are two ways to go ahead. Either we give up on the deprecation and fully revert 58056f77502f as well or we can keep kmem.limit_in_bytes but make the write a noop and warn about the fact. This should work for both known breaking workloads which depend on the existence but do not depend on the hard limit enforcement. Note to backporters to stable trees. a8c49af3be5f ("memcg: add per-memcg total kernel memory stat") introduced in 4.18 has added memcg_account_kmem so the accounting is not done by obj_cgroup_charge_pages directly for v1 anymore. Prior kernels need to add it explicitly (thanks to Johannes for pointing this out). [akpm@linux-foundation.org: fix build - remove unused local] Link: http://lkml.kernel.org/r/20230920081101.GA12096@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net [1] Link: https://lkml.kernel.org/r/ZRE5VJozPZt9bRPy@dhcp22.suse.cz Fixes: 86327e8eb94c ("memcg: drop kmem.limit_in_bytes") Fixes: 58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes") Signed-off-by: Michal Hocko Acked-by: Shakeel Butt Acked-by: Johannes Weiner Cc: Greg Kroah-Hartman Cc: Jeremi Piotrowski Cc: Muchun Song Cc: Roman Gushchin Cc: Tejun heo Cc: Signed-off-by: Andrew Morton

Merge tag 'cgroup-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2023-09-01T22:58:21+00:00

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 ...

Merge tag 'docs-6.6' of git://git.lwn.net/linux

2023-08-31T03:05:42+00:00

Pull documentation updates from Jonathan Corbet: "Documentation work keeps chugging along; this includes: - Work from Carlos Bilbao to integrate rustdoc output into the generated HTML documentation. This took some work to figure out how to do it without slowing the docs build and without creating people who don't have Rust installed, but Carlos got there - Move the loongarch and mips architecture documentation under Documentation/arch/ - Some more maintainer documentation from Jakub ... plus the usual assortment of updates, translations, and fixes" * tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits) Docu: genericirq.rst: fix irq-example input: docs: pxrc: remove reference to phoenix-sim Documentation: serial-console: Fix literal block marker docs/mm: remove references to hmm_mirror ops and clean typos docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add() Documentation: Fix typos Documentation/ABI: Fix typos scripts: kernel-doc: fix macro handling in enums scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN] Documentation: riscv: Update boot image header since EFI stub is supported Documentation: riscv: Add early boot document Documentation: arm: Add bootargs to the table of added DT parameters docs: kernel-parameters: Refer to the correct bitmap function doc: update params of memhp_default_state= docs: Add book to process/kernel-docs.rst docs: sparse: fix invalid link addresses docs: vfs: clean up after the iterate() removal docs: Add a section on surveys to the researcher guidelines docs: move mips under arch docs: move loongarch under arch ...

memcg: drop kmem.limit_in_bytes

2023-08-18T17:12:11+00:00

kmem.limit_in_bytes (v1 way to limit kernel memory usage) has been deprecated since 58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes") merged in 5.16. We haven't heard about any serious users since then but it seems that the mere presence of the file is causing more harm thatn good. We (SUSE) have had several bug reports from customers where Docker based containers started to fail because a write to kmem.limit_in_bytes has failed. This was unexpected because runc code only expects ENOENT (kmem disabled) or EBUSY (tasks already running within cgroup). So a new error code was unexpected and the whole container startup failed. This has been later addressed by https://github.com/opencontainers/runc/commit/52390d68040637dfc77f9fda6bbe70952423d380 so current Docker runtimes do not suffer from the problem anymore. There are still older version of Docker in use and likely hard to get rid of completely. Address this by wiping out the file completely and effectively get back to pre 4.5 era and CONFIG_MEMCG_KMEM=n configuration. I would recommend backporting to stable trees which have picked up 58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes"). [mhocko@suse.com: restore _KMEM switch case] Link: https://lkml.kernel.org/r/ZKe5wxdbvPi5Cwd7@dhcp22.suse.cz Link: https://lkml.kernel.org/r/20230704115240.14672-1-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Shakeel Butt Acked-by: Johannes Weiner Acked-by: Roman Gushchin Cc: Muchun Song Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton

docs: cgroup-v1: replace dead CONFIG_MEM_RES_CTRL_SWAP symbol

2023-07-31T15:55:12+00:00

Commit e55b9f96860f ("mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol") removed MEMCG_SWAP as it was just a shorthand for CONFIG_MEMCG && CONFIG_SWAP. The commit also adjusted the documentation but missed reference to CONFIG_MEM_RES_CTRL_SWAP, which was the previous name of CONFIG_MEMCG_SWAP before renaming in commit c255a458055e ("memcg: rename config variables"). Update the reference to the current state. Signed-off-by: Krzysztof Pawlaczyk Reviewed-by: Lukas Bulwahn Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20230728105723.251892-1-krzpaw@gmail.com

docs: cgroup-v1: fix typo

2023-07-21T18:11:41+00:00

"listers" -> "listeners" Signed-off-by: Xiongwei Song Signed-off-by: Tejun Heo

docs: cgroup-v1: correct the term of Page Cache organization in inode

2023-07-21T18:11:27+00:00

The radix-tree for Page Cache has been replaced with xarray, see commit eb797a8ee0ab ("page cache: Rearrange address_space"), so move "radix-tree" to "xarray". Signed-off-by: Xiongwei Song Signed-off-by: Tejun Heo

mm: kill lock|unlock_page_memcg()

2023-06-19T23:19:33+00:00

Since commit c7c3dec1c9db ("mm: rmap: remove lock_page_memcg()"), no more user, kill lock_page_memcg() and unlock_page_memcg(). Link: https://lkml.kernel.org/r/20230614143612.62575-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: Johannes Weiner Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

docs: cgroup-v1/cpusets: update libcgroup project link

2023-04-14T16:55:48+00:00

Update the libcgroup project link, in the cgroup v1/cpusets documentation. Signed-off-by: Kamalesh Babulal Signed-off-by: Tejun Heo

Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-02-24T01:09:35+00:00

Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...