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3 daysMerge tag 'cgroup-for-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - Allow css_rstat_updated() in NMI context to enable memory accounting for allocations in NMI context. - /proc/cgroups doesn't contain useful information for cgroup2 and was updated to only show v1 controllers. This unfortunately broke something in the wild. Add an option to bring back the old behavior to ease transition. - selftest updates and other cleanups. * tag 'cgroup-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Add compatibility option for content of /proc/cgroups selftests/cgroup: fix cpu.max tests cgroup: llist: avoid memory tears for llist_node selftests: cgroup: Fix missing newline in test_zswap_writeback_one selftests: cgroup: Allow longer timeout for kmem_dead_cgroups cleanup memcg: cgroup: call css_rstat_updated irrespective of in_nmi() cgroup: remove per-cpu per-subsystem locks cgroup: make css_rstat_updated nmi safe cgroup: support to enable nmi-safe css_rstat_updated selftests: cgroup: Fix compilation on pre-cgroupns kernels selftests: cgroup: Optionally set up v1 environment selftests: cgroup: Add support for named v1 hierarchies in test_core selftests: cgroup_util: Add helpers for testing named v1 hierarchies Documentation: cgroup: add section explaining controller availability cgroup: Drop sock_cgroup_classid() dummy implementation
2025-07-09Revert "sched/numa: add statistics of numa balance task"Chen Yu
This reverts commit ad6b26b6a0a79166b53209df2ca1cf8636296382. This commit introduces per-memcg/task NUMA balance statistics, but unfortunately it introduced a NULL pointer exception due to the following race condition: After a swap task candidate was chosen, its mm_struct pointer was set to NULL due to task exit. Later, when performing the actual task swapping, the p->mm caused the problem. CPU0 CPU1 : ... task_numa_migrate task_numa_find_cpu task_numa_compare # a normal task p is chosen env->best_task = p # p exit: exit_signals(p); p->flags |= PF_EXITING exit_mm p->mm = NULL; migrate_swap_stop __migrate_swap_task((arg->src_task, arg->dst_cpu) count_memcg_event_mm(p->mm, NUMA_TASK_SWAP)# p->mm is NULL task_lock() should be held and the PF_EXITING flag needs to be checked to prevent this from happening. After discussion, the conclusion was that adding a lock is not worthwhile for some statistics calculations. Revert the change and rely on the tracepoint for this purpose. Link: https://lkml.kernel.org/r/20250704135620.685752-1-yu.c.chen@intel.com Link: https://lkml.kernel.org/r/20250708064917.BBD13C4CEED@smtp.kernel.org Fixes: ad6b26b6a0a7 ("sched/numa: add statistics of numa balance task") Signed-off-by: Chen Yu <yu.c.chen@intel.com> Reported-by: Jirka Hladky <jhladky@redhat.com> Closes: https://lore.kernel.org/all/CAE4VaGBLJxpd=NeRJXpSCuw=REhC5LWJpC29kDy-Zh2ZDyzQZA@mail.gmail.com/ Reported-by: Srikanth Aithal <Srikanth.Aithal@amd.com> Reported-by: Suneeth D <Suneeth.D@amd.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Hladky <jhladky@redhat.com> Cc: Libo Chen <libo.chen@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-09Documentation: cgroup: add section explaining controller availabilityVishal Chourasia
Add "Availability" section to Control Group v2 docs. It describes the meaning of a controller being available in a cgroup, complementing the existing "Enabling and Disabling" section. This update improves the clarity of cgroup controller management by explicitly distinguishing between: 1. Availability – when a controller is supported by the kernel and listed in "cgroup.controllers", making its interface files accessible in the cgroup's directory. 2. Enabling – when a controller is enabled via explicitly writing the name of the controller to "cgroup.subtree_control" to control distribution of resource across the cgroup's immediate children. As an example, consider /sys/fs/cgroup # cat cgroup.controllers cpuset cpu io memory hugetlb pids misc /sys/fs/cgroup # cat cgroup.subtree_control # No controllers enabled by default /sys/fs/cgroup # echo +cpu +memory > cgroup.subtree_control # enabling "cpu" and "memory" /sys/fs/cgroup # cat cgroup.subtree_control cpu memory # cpu and memory enabled in /sys/fs/cgroup /sys/fs/cgroup # mkdir foo_cgrp /sys/fs/cgroup # cd foo_cgrp/ /sys/fs/cgroup/foo_cgrp # cat cgroup.controllers cpu memory # cpu and memory available in 'foo_cgrp' /sys/fs/cgroup/foo_cgrp # cat cgroup.subtree_control # empty by default /sys/fs/cgroup/foo_cgrp # ls cgroup.controllers cpu.max.burst memory.numa_stat cgroup.events cpu.pressure memory.oom.group cgroup.freeze cpu.stat memory.peak cgroup.kill cpu.stat.local memory.pressure cgroup.max.depth cpu.weight memory.reclaim cgroup.max.descendants cpu.weight.nice memory.stat cgroup.pressure io.pressure memory.swap.current cgroup.procs memory.current memory.swap.events cgroup.stat memory.events memory.swap.high cgroup.subtree_control memory.events.local memory.swap.max cgroup.threads memory.high memory.swap.peak cgroup.type memory.low memory.zswap.current cpu.idle memory.max memory.zswap.max cpu.max memory.min memory.zswap.writeback In this example, "cpu" and "memory" are enabled in the root cgroup, making them available in "foo_cgrp". This exposes the corresponding interface files in "foo_cgrp/", allowing resource control of processes in that cgroup. However, these controllers are not yet enabled in "foo_cgrp" itself. Once a controller is available in a cgroup it can be used to resource control processes of the cgroup. Acked-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-06-02Merge tag 'mm-stable-2025-06-01-14-06' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "zram: support algorithm-specific parameters" from Sergey Senozhatsky adds infrastructure for passing algorithm-specific parameters into zram. A single parameter `winbits' is implemented at this time. - "memcg: nmi-safe kmem charging" from Shakeel Butt makes memcg charging nmi-safe, which is required by BFP, which can operate in NMI context. - "Some random fixes and cleanup to shmem" from Kemeng Shi implements small fixes and cleanups in the shmem code. - "Skip mm selftests instead when kernel features are not present" from Zi Yan fixes some issues in the MM selftest code. - "mm/damon: build-enable essential DAMON components by default" from SeongJae Park reworks DAMON Kconfig to make it easier to enable CONFIG_DAMON. - "sched/numa: add statistics of numa balance task migration" from Libo Chen adds more info into sysfs and procfs files to improve visibility into the NUMA balancer's task migration activity. - "selftests/mm: cow and gup_longterm cleanups" from Mark Brown provides various updates to some of the MM selftests to make them play better with the overall containing framework. * tag 'mm-stable-2025-06-01-14-06' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (43 commits) mm/khugepaged: clean up refcount check using folio_expected_ref_count() selftests/mm: fix test result reporting in gup_longterm selftests/mm: report unique test names for each cow test selftests/mm: add helper for logging test start and results selftests/mm: use standard ksft_finished() in cow and gup_longterm selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled sched/numa: add statistics of numa balance task sched/numa: fix task swap by skipping kernel threads tools/testing: check correct variable in open_procmap() tools/testing/vma: add missing function stub mm/gup: update comment explaining why gup_fast() disables IRQs selftests/mm: two fixes for the pfnmap test mm/khugepaged: fix race with folio split/free using temporary reference mm: add CONFIG_PAGE_BLOCK_ORDER to select page block order mmu_notifiers: remove leftover stub macros selftests/mm: deduplicate test names in madv_populate kcov: rust: add flags for KCOV with Rust mm: rust: make CONFIG_MMU ifdefs more narrow mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables() mm/damon/Kconfig: enable CONFIG_DAMON by default ...
2025-05-31sched/numa: add statistics of numa balance taskChen Yu
On systems with NUMA balancing enabled, it has been found that tracking task activities resulting from NUMA balancing is beneficial. NUMA balancing employs two mechanisms for task migration: one is to migrate a task to an idle CPU within its preferred node, and the other is to swap tasks located on different nodes when they are on each other's preferred nodes. The kernel already provides NUMA page migration statistics in /sys/fs/cgroup/mytest/memory.stat and /proc/{PID}/sched. However, it lacks statistics regarding task migration and swapping. Therefore, relevant counts for task migration and swapping should be added. The following two new fields: numa_task_migrated numa_task_swapped will be shown in /sys/fs/cgroup/{GROUP}/memory.stat, /proc/{PID}/sched and /proc/vmstat. Introducing both per-task and per-memory cgroup (memcg) NUMA balancing statistics facilitates a rapid evaluation of the performance and resource utilization of the target workload. For instance, users can first identify the container with high NUMA balancing activity and then further pinpoint a specific task within that group, and subsequently adjust the memory policy for that task. In short, although it is possible to iterate through /proc/$pid/sched to locate the problematic task, the introduction of aggregated NUMA balancing activity for tasks within each memcg can assist users in identifying the task more efficiently through a divide-and-conquer approach. As Libo Chen pointed out, the memcg event relies on the text names in vmstat_text, and /proc/vmstat generates corresponding items based on vmstat_text. Thus, the relevant task migration and swapping events introduced in vmstat_text also need to be populated by count_vm_numa_event(), otherwise these values are zero in /proc/vmstat. In theory, task migration and swap events are part of the scheduler's activities. The reason for exposing them through the memory.stat/vmstat interface is that we already have NUMA balancing statistics in memory.stat/vmstat, and these events are closely related to each other. Following Shakeel's suggestion, we describe the end-to-end flow/story of all these events occurring on a timeline for future reference: The goal of NUMA balancing is to co-locate a task and its memory pages on the same NUMA node. There are two strategies: migrate the pages to the task's node, or migrate the task to the node where its pages reside. Suppose a task p1 is running on Node 0, but its pages are located on Node 1. NUMA page fault statistics for p1 reveal its "page footprint" across nodes. If NUMA balancing detects that most of p1's pages are on Node 1: 1.Page Migration Attempt: The Numa balance first tries to migrate p1's pages to Node 0. The numa_page_migrate counter increments. 2.Task Migration Strategies: After the page migration finishes, Numa balance checks every 1 second to see if p1 can be migrated to Node 1. Case 2.1: Idle CPU Available If Node 1 has an idle CPU, p1 is directly scheduled there. This event is logged as numa_task_migrated. Case 2.2: No Idle CPU (Task Swap) If all CPUs on Node1 are busy, direct migration could cause CPU contention or load imbalance. Instead: The Numa balance selects a candidate task p2 on Node 1 that prefers Node 0 (e.g., due to its own page footprint). p1 and p2 are swapped. This cross-node swap is recorded as numa_task_swapped. Link: https://lkml.kernel.org/r/d00edb12ba0f0de3c5222f61487e65f2ac58f5b1.1748493462.git.yu.c.chen@intel.com Link: https://lkml.kernel.org/r/7ef90a88602ed536be46eba7152ed0d33bad5790.1748002400.git.yu.c.chen@intel.com Signed-off-by: Chen Yu <yu.c.chen@intel.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Ayush Jain <Ayush.jain3@amd.com> Cc: "Chen, Tim C" <tim.c.chen@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Libo Chen <libo.chen@oracle.com> Cc: Mel Gorman <mgorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31Merge tag 'mm-stable-2025-05-31-14-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ...
2025-05-27Merge tag 'cgroup-for-6.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - cgroup rstat shared the tracking tree across all controllers with the rationale being that a cgroup which is using one resource is likely to be using other resources at the same time (ie. if something is allocating memory, it's probably consuming CPU cycles). However, this turned out to not scale very well especially with memcg using rstat for internal operations which made memcg stat read and flush patterns substantially different from other controllers. JP Kobryn split the rstat tree per controller. - cgroup BPF support was hooking into cgroup init/exit paths directly. Convert them to use a notifier chain instead so that other usages can be added easily. The two of the patches which implement this are mislabeled as belonging to sched_ext instead of cgroup. Sorry. - Relatively minor cpuset updates - Documentation updates * tag 'cgroup-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (23 commits) sched_ext: Convert cgroup BPF support to use cgroup_lifetime_notifier sched_ext: Introduce cgroup_lifetime_notifier cgroup: Minor reorganization of cgroup_create() cgroup, docs: cpu controller's interaction with various scheduling policies cgroup, docs: convert space indentation to tab indentation cgroup: avoid per-cpu allocation of size zero rstat cpu locks cgroup, docs: be specific about bandwidth control of rt processes cgroup: document the rstat per-cpu initialization cgroup: helper for checking rstat participation of css cgroup: use subsystem-specific rstat locks to avoid contention cgroup: use separate rstat trees for each subsystem cgroup: compare css to cgroup::self in helper for distingushing css cgroup: warn on rstat usage by early init subsystems cgroup/cpuset: drop useless cpumask_empty() in compute_effective_exclusive_cpumask() cgroup/rstat: Improve cgroup_rstat_push_children() documentation cgroup: fix goto ordering in cgroup_init() cgroup: fix pointer check in css_rstat_init() cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs cgroup/cpuset: Fix obsolete comment in cpuset_css_offline() cgroup/cpuset: Always use cpu_active_mask ...
2025-05-22cgroup, docs: cpu controller's interaction with various scheduling policiesShashank Balaji
The cpu controller interface files account for or affect processes differently based on their scheduling policy, and the underlying scheduler used (fair-class vs. BPF scheduler). Document these differences Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-22cgroup, docs: convert space indentation to tab indentationShashank Balaji
The paragraphs on cpu.uclamp.{min,max} are space indented. Convert them to tab indentation to make them uniform with the other paragraphs. Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-21cgroup, docs: be specific about bandwidth control of rt processesShashank Balaji
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-12mm: add swappiness=max arg to memory.reclaim for only anon reclaimZhongkun He
Patch series "add max arg to swappiness in memory.reclaim and lru_gen", v4. This patchset adds max arg to swappiness in memory.reclaim and lru_gen for anon only proactive memory reclaim. With commit <68cd9050d871> ("mm: add swappiness= arg to memory.reclaim") we can submit an additional swappiness=<val> argument to memory.reclaim. It is very useful because we can dynamically adjust the reclamation ratio based on the anonymous folios and file folios of each cgroup. For example,when swappiness is set to 0, we only reclaim from file folios. But we can not relciam memory just from anon folios. This patchset introduces a new macro, SWAPPINESS_ANON_ONLY, defined as MAX_SWAPPINESS + 1, represent the max arg semantics. It specifically indicates that reclamation should occur only from anonymous pages. Patch 1 adds swappiness=max arg to memory.reclaim suggested-by: Yosry Ahmed Patch 2 add more comments for cache_trim_mode from Johannes Weiner in [1]. Patch 3 add max arg to lru_gen for proactive memory reclaim in MGLRU. The MGLRU already supports reclaiming exclusively from anonymous pages. This patch formalizes that behavior by introducing a max parameter to represent the corresponding semantics. Patch 4 using SWAPPINESS_ANON_ONLY in MGLRU Using SWAPPINESS_ANON_ONLY instead of MAX_SWAPPINESS + 1 to indicate reclaiming only from anonymous pages makes the code more readable and explicit Here is the previous discussion: https://lore.kernel.org/all/20250314033350.1156370-1-hezhongkun.hzk@bytedance.com/ https://lore.kernel.org/all/20250312094337.2296278-1-hezhongkun.hzk@bytedance.com/ https://lore.kernel.org/all/20250318135330.3358345-1-hezhongkun.hzk@bytedance.com/ This patch (of 4): With commit <68cd9050d871> ("mm: add swappiness= arg to memory.reclaim") we can submit an additional swappiness=<val> argument to memory.reclaim. It is very useful because we can dynamically adjust the reclamation ratio based on the anonymous folios and file folios of each cgroup. For example,when swappiness is set to 0, we only reclaim from file folios. However,we have also encountered a new issue: when swappiness is set to the MAX_SWAPPINESS, it may still only reclaim file folios. So, we hope to add a new arg 'swappiness=max' in memory.reclaim where proactive memory reclaim only reclaims from anonymous folios when swappiness is set to max. The swappiness semantics from a user perspective remain unchanged. For example, something like this: echo "2M swappiness=max" > /sys/fs/cgroup/memory.reclaim will perform reclaim on the rootcg with a swappiness setting of 'max' (a new mode) regardless of the file folios. Users have a more comprehensive view of the application's memory distribution because there are many metrics available. For example, if we find that a certain cgroup has a large number of inactive anon folios, we can reclaim only those and skip file folios, because with the zram/zswap, the IO tradeoff that cache_trim_mode or other file first logic is making doesn't hold - file refaults will cause IO, whereas anon decompression will not. With this patch, the swappiness argument of memory.reclaim has a new mode 'max', means reclaiming just from anonymous folios both in traditional LRU and MGLRU. Link: https://lkml.kernel.org/r/cover.1745225696.git.hezhongkun.hzk@bytedance.com Link: https://lore.kernel.org/all/20250314141833.GA1316033@cmpxchg.org/ [1] Link: https://lkml.kernel.org/r/519e12b9b1f8c31a01e228c8b4b91a2419684f77.1745225696.git.hezhongkun.hzk@bytedance.com Signed-off-by: Zhongkun He <hezhongkun.hzk@bytedance.com> Suggested-by: Yosry Ahmed <yosry.ahmed@linux.dev> Acked-by: Muchun Song <muchun.song@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-12memcg-introduce-non-blocking-limit-setting-option-v3Shakeel Butt
add more explanation in doc and commit message on O_NONBLOCK side-effects (Johannes) Link: https://lkml.kernel.org/r/20250506232833.3109790-1-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Greg Thelen <gthelen@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Yosry Ahmed <yosry.ahmed@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-12memcg: introduce non-blocking limit setting optionShakeel Butt
Setting the max and high limits can trigger synchronous reclaim and/or oom-kill if the usage is higher than the given limit. This behavior is fine for newly created cgroups but it can cause issues for the node controller while setting limits for existing cgroups. In our production multi-tenant and overcommitted environment, we are seeing priority inversion when the node controller dynamically adjusts the limits of running jobs of different priorities. Based on the system situation, the node controller may reduce the limits of lower priority jobs and increase the limits of higher priority jobs. However we are seeing node controller getting stuck for long period of time while reclaiming from lower priority jobs while setting their limits and also spends a lot of its own CPU. One of the workaround we are trying is to fork a new process which sets the limit of the lower priority job along with setting an alarm to get itself killed if it get stuck in the reclaim for lower priority job. However we are finding it very unreliable and costly. Either we need a good enough time buffer for the alarm to be delivered after setting limit and potentialy spend a lot of CPU in the reclaim or be unreliable in setting the limit for much shorter but cheaper (less reclaim) alarms. Let's introduce new limit setting option which does not trigger reclaim and/or oom-kill and let the processes in the target cgroup to trigger reclaim and/or throttling and/or oom-kill in their next charge request. This will make the node controller on multi-tenant overcommitted environment much more reliable. Explanation from Johannes on side-effects of O_NONBLOCK limit change: It's usually the allocating tasks inside the group bearing the cost of limit enforcement and reclaim. This allows a (privileged) updater from outside the group to keep that cost in there - instead of having to help, from a context that doesn't necessarily make sense. I suppose the tradeoff with that - and the reason why this was doing sync reclaim in the first place - is that, if the group is idle and not trying to allocate more, it can take indefinitely for the new limit to actually be met. It should be okay in most scenarios in practice. As the capacity is reallocated from group A to B, B will exert pressure on A once it tries to claim it and thereby shrink it down. If A is idle, that shouldn't be hard. If A is running, it's likely to fault/allocate soon-ish and then join the effort. It does leave a (malicious) corner case where A is just busy-hitting its memory to interfere with the clawback. This is comparable to reclaiming memory.low overage from the outside, though, which is an acceptable risk. Users of O_NONBLOCK just need to be aware. Link: https://lkml.kernel.org/r/20250419183545.1982187-1-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Thelen <gthelen@google.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Yosry Ahmed <yosry.ahmed@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-07fs: Remove aops->writepageMatthew Wilcox (Oracle)
All callers and implementations are now removed, so remove the operation and update the documentation to match. Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org> Link: https://lore.kernel.org/r/20250402150005.2309458-10-willy@infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-24Merge tag 'cgroup-for-6.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - Add deprecation info messages to cgroup1-only features - rstat updates including a bug fix and breaking up a critical section to reduce interrupt latency impact - Other misc and doc updates * tag 'cgroup-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: rstat: Cleanup flushing functions and locking cgroup/rstat: avoid disabling irqs for O(num_cpu) mm: Fix a build breakage in memcontrol-v1.c blk-cgroup: Simplify policy files registration cgroup: Update file naming comment cgroup: Add deprecation message to legacy freezer controller mm: Add transformation message for per-memcg swappiness RFC cgroup/cpuset-v1: Add deprecation messages to sched_relax_domain_level cgroup/cpuset-v1: Add deprecation messages to memory_migrate cgroup/cpuset-v1: Add deprecation messages to mem_exclusive and mem_hardwall cgroup: Print message when /proc/cgroups is read on v2-only system cgroup/blkio: Add deprecation messages to reset_stats cgroup/cpuset-v1: Add deprecation messages to memory_spread_page and memory_spread_slab cgroup/cpuset-v1: Add deprecation messages to sched_load_balance and memory_pressure_enabled cgroup, docs: Be explicit about independence of RT_GROUP_SCHED and non-cpu controllers cgroup/rstat: Fix forceidle time in cpu.stat cgroup/misc: Remove unused misc_cg_res_total_usage cgroup/cpuset: Move procfs cpuset attribute under cgroup-v1.c cgroup: update comment about dropping cgroup kn refs
2025-03-21cgroup: docs: add pswpin and pswpout items in cgroup v2 docHao Jia
The commit 15ff4d409e1a ("mm/memcontrol: add per-memcg pgpgin/pswpin counter") introduced the pswpin and pswpout items in the memory.stat of cgroup v2. Therefore, update them accordingly in the cgroup-v2 documentation. Link: https://lkml.kernel.org/r/20250318075833.90615-3-jiahao.kernel@gmail.com Fixes: 15ff4d409e1a ("mm/memcontrol: add per-memcg pgpgin/pswpin counter") Signed-off-by: Hao Jia <jiahao1@lixiang.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-21mm: vmscan: split proactive reclaim statistics from direct reclaim statisticsHao Jia
Patch series "Adding Proactive Memory Reclaim Statistics". These two patches are related to proactive memory reclaim. Patch 1 Split proactive reclaim statistics from direct reclaim counters and introduces new counters: pgsteal_proactive, pgdemote_proactive, and pgscan_proactive. Patch 2 Adds pswpin and pswpout items to the cgroup-v2 documentation. This patch (of 2): In proactive memory reclaim scenarios, it is necessary to accurately track proactive reclaim statistics to dynamically adjust the frequency and amount of memory being reclaimed proactively. Currently, proactive reclaim is included in direct reclaim statistics, which can make these direct reclaim statistics misleading. Therefore, separate proactive reclaim memory from the direct reclaim counters by introducing new counters: pgsteal_proactive, pgdemote_proactive, and pgscan_proactive, to avoid confusion with direct reclaim. Link: https://lkml.kernel.org/r/20250318075833.90615-1-jiahao.kernel@gmail.com Link: https://lkml.kernel.org/r/20250318075833.90615-2-jiahao.kernel@gmail.com Signed-off-by: Hao Jia <jiahao1@lixiang.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17mm: stop maintaining the per-page mapcount of large folios ↵David Hildenbrand
(CONFIG_NO_PAGE_MAPCOUNT) Everything is in place to stop using the per-page mapcounts in large folios: the mapcount of tail pages will always be logically 0 (-1 value), just like it currently is for hugetlb folios already, and the page mapcount of the head page is either 0 (-1 value) or contains a page type (e.g., hugetlb). Maintaining _nr_pages_mapped without per-page mapcounts is impossible, so that one also has to go with CONFIG_NO_PAGE_MAPCOUNT. There are two remaining implications: (1) Per-node, per-cgroup and per-lruvec stats of "NR_ANON_MAPPED" ("mapped anonymous memory") and "NR_FILE_MAPPED" ("mapped file memory"): As soon as any page of the folio is mapped -- folio_mapped() -- we now account the complete folio as mapped. Once the last page is unmapped -- !folio_mapped() -- we account the complete folio as unmapped. This implies that ... * "AnonPages" and "Mapped" in /proc/meminfo and /sys/devices/system/node/*/meminfo * cgroup v2: "anon" and "file_mapped" in "memory.stat" and "memory.numa_stat" * cgroup v1: "rss" and "mapped_file" in "memory.stat" and "memory.numa_stat ... can now appear higher than before. But note that these folios do consume that memory, simply not all pages are actually currently mapped. It's worth nothing that other accounting in the kernel (esp. cgroup charging on allocation) is not affected by this change. [why oh why is "anon" called "rss" in cgroup v1] (2) Detecting partial mappings Detecting whether anon THPs are partially mapped gets a bit more unreliable. As long as a single MM maps such a large folio ("exclusively mapped"), we can reliably detect it. Especially before fork() / after a short-lived child process quit, we will detect partial mappings reliably, which is the common case. In essence, if the average per-page mapcount in an anon THP is < 1, we know for sure that we have a partial mapping. However, as soon as multiple MMs are involved, we might miss detecting partial mappings: this might be relevant with long-lived child processes. If we have a fully-mapped anon folio before fork(), once our child processes and our parent all unmap (zap/COW) the same pages (but not the complete folio), we might not detect the partial mapping. However, once the child processes quit we would detect the partial mapping. How relevant this case is in practice remains to be seen. Swapout/migration will likely mitigate this. In the future, RMAP walkers could check for that for that case (e.g., when collecting access bits during reclaim) and simply flag them for deferred-splitting. Link: https://lkml.kernel.org/r/20250303163014.1128035-21-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirks^H^Hski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michal Koutn <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: tejun heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-05cgroup, docs: Be explicit about independence of RT_GROUP_SCHED and non-cpu ↵Shashank Balaji
controllers The cgroup v2 cpu controller has a limitation that if CONFIG_RT_GROUP_SCHED is enabled, the cpu controller can be enabled only if all the realtime processes are in the root cgroup. The other controllers have no such restriction. They can be used for the resource control of realtime processes irrespective of whether CONFIG_RT_GROUP_SCHED is enabled or not. Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com> Acked-by: Waiman Long <longman@redhat.com> Acked-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-01-06kernel/cgroup: Add "dmem" memory accounting cgroupMaarten Lankhorst
This code is based on the RDMA and misc cgroup initially, but now uses page_counter. It uses the same min/low/max semantics as the memory cgroup as a result. There's a small mismatch as TTM uses u64, and page_counter long pages. In practice it's not a problem. 32-bits systems don't really come with >=4GB cards and as long as we're consistently wrong with units, it's fine. The device page size may not be in the same units as kernel page size, and each region might also have a different page size (VRAM vs GART for example). The interface is simple: - Call dmem_cgroup_register_region() - Use dmem_cgroup_try_charge to check if you can allocate a chunk of memory, use dmem_cgroup__uncharge when freeing it. This may return an error code, or -EAGAIN when the cgroup limit is reached. In that case a reference to the limiting pool is returned. - The limiting cs can be used as compare function for dmem_cgroup_state_evict_valuable. - After having evicted enough, drop reference to limiting cs with dmem_cgroup_pool_state_put. This API allows you to limit device resources with cgroups. You can see the supported cards in /sys/fs/cgroup/dmem.capacity You need to echo +dmem to cgroup.subtree_control, and then you can partition device memory. Co-developed-by: Friedrich Vock <friedrich.vock@gmx.de> Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de> Co-developed-by: Maxime Ripard <mripard@kernel.org> Signed-off-by: Maarten Lankhorst <dev@lankhorst.se> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20241204143112.1250983-1-dev@lankhorst.se Signed-off-by: Maxime Ripard <mripard@kernel.org>
2024-11-23Merge tag 'mm-stable-2024-11-18-19-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...
2024-11-18Merge tag 'vfs-6.13.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Fixup and improve NLM and kNFSD file lock callbacks Last year both GFS2 and OCFS2 had some work done to make their locking more robust when exported over NFS. Unfortunately, part of that work caused both NLM (for NFS v3 exports) and kNFSD (for NFSv4.1+ exports) to no longer send lock notifications to clients This in itself is not a huge problem because most NFS clients will still poll the server in order to acquire a conflicted lock It's important for NLM and kNFSD that they do not block their kernel threads inside filesystem's file_lock implementations because that can produce deadlocks. We used to make sure of this by only trusting that posix_lock_file() can correctly handle blocking lock calls asynchronously, so the lock managers would only setup their file_lock requests for async callbacks if the filesystem did not define its own lock() file operation However, when GFS2 and OCFS2 grew the capability to correctly handle blocking lock requests asynchronously, they started signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check for also trusting posix_lock_file() was inadvertently dropped, so now most filesystems no longer produce lock notifications when exported over NFS Fix this by using an fop_flag which greatly simplifies the problem and grooms the way for future uses by both filesystems and lock managers alike - Add a sysctl to delete the dentry when a file is removed instead of making it a negative dentry Commit 681ce8623567 ("vfs: Delete the associated dentry when deleting a file") introduced an unconditional deletion of the associated dentry when a file is removed. However, this led to performance regressions in specific benchmarks, such as ilebench.sum_operations/s, prompting a revert in commit 4a4be1ad3a6e ("Revert "vfs: Delete the associated dentry when deleting a file""). This reintroduces the concept conditionally through a sysctl - Expand the statmount() system call: * Report the filesystem subtype in a new fs_subtype field to e.g., report fuse filesystem subtypes * Report the superblock source in a new sb_source field * Add a new way to return filesystem specific mount options in an option array that returns filesystem specific mount options separated by zero bytes and unescaped. This allows caller's to retrieve filesystem specific mount options and immediately pass them to e.g., fsconfig() without having to unescape or split them * Report security (LSM) specific mount options in a separate security option array. We don't lump them together with filesystem specific mount options as security mount options are generic and most users aren't interested in them The format is the same as for the filesystem specific mount option array - Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command - Optimize acl_permission_check() to avoid costly {g,u}id ownership checks if possible - Use smp_mb__after_spinlock() to avoid full smp_mb() in evict() - Add synchronous wakeup support for ep_poll_callback. Currently, epoll only uses wake_up() to wake up task. But sometimes there are epoll users which want to use the synchronous wakeup flag to give a hint to the scheduler, e.g., the Android binder driver. So add a wake_up_sync() define, and use wake_up_sync() when sync is true in ep_poll_callback() Fixes: - Fix kernel documentation for inode_insert5() and iget5_locked() - Annotate racy epoll check on file->f_ep - Make F_DUPFD_QUERY associative - Avoid filename buffer overrun in initramfs - Don't let statmount() return empty strings - Add a cond_resched() to dump_user_range() to avoid hogging the CPU - Don't query the device logical blocksize multiple times for hfsplus - Make filemap_read() check that the offset is positive or zero Cleanups: - Various typo fixes - Cleanup wbc_attach_fdatawrite_inode() - Add __releases annotation to wbc_attach_and_unlock_inode() - Add hugetlbfs tracepoints - Fix various vfs kernel doc parameters - Remove obsolete TODO comment from io_cancel() - Convert wbc_account_cgroup_owner() to take a folio - Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add() - Reorder struct posix_acl to save 8 bytes - Annotate struct posix_acl with __counted_by() - Replace one-element array with flexible array member in freevxfs - Use idiomatic atomic64_inc_return() in alloc_mnt_ns()" * tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits) statmount: retrieve security mount options vfs: make evict() use smp_mb__after_spinlock instead of smp_mb statmount: add flag to retrieve unescaped options fs: add the ability for statmount() to report the sb_source writeback: wbc_attach_fdatawrite_inode out of line writeback: add a __releases annoation to wbc_attach_and_unlock_inode fs: add the ability for statmount() to report the fs_subtype fs: don't let statmount return empty strings fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel() hfsplus: don't query the device logical block size multiple times freevxfs: Replace one-element array with flexible array member fs: optimize acl_permission_check() initramfs: avoid filename buffer overrun fs/writeback: convert wbc_account_cgroup_owner to take a folio acl: Annotate struct posix_acl with __counted_by() acl: Realign struct posix_acl to save 8 bytes epoll: Add synchronous wakeup support for ep_poll_callback coredump: add cond_resched() to dump_user_range mm/page-writeback.c: Fix comment of wb_domain_writeout_add() mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL ...
2024-11-14memcg/hugetlb: add hugeTLB counters to memcgJoshua Hahn
This patch introduces a new counter to memory.stat that tracks hugeTLB usage, only if hugeTLB accounting is done to memory.current. This feature is enabled the same way hugeTLB accounting is enabled, via the memory_hugetlb_accounting mount flag for cgroupsv2. 1. Why is this patch necessary? Currently, memcg hugeTLB accounting is an opt-in feature [1] that adds hugeTLB usage to memory.current. However, the metric is not reported in memory.stat. Given that users often interpret memory.stat as a breakdown of the value reported in memory.current, the disparity between the two reports can be confusing. This patch solves this problem by including the metric in memory.stat as well, but only if it is also reported in memory.current (it would also be confusing if the value was reported in memory.stat, but not in memory.current) Aside from the consistency between the two files, we also see benefits in observability. Userspace might be interested in the hugeTLB footprint of cgroups for many reasons. For instance, system admins might want to verify that hugeTLB usage is distributed as expected across tasks: i.e. memory-intensive tasks are using more hugeTLB pages than tasks that don't consume a lot of memory, or are seen to fault frequently. Note that this is separate from wanting to inspect the distribution for limiting purposes (in which case, hugeTLB controller makes more sense). 2. We already have a hugeTLB controller. Why not use that? It is true that hugeTLB tracks the exact value that we want. In fact, by enabling the hugeTLB controller, we get all of the observability benefits that I mentioned above, and users can check the total hugeTLB usage, verify if it is distributed as expected, etc. With this said, there are 2 problems: (a) They are still not reported in memory.stat, which means the disparity between the memcg reports are still there. (b) We cannot reasonably expect users to enable the hugeTLB controller just for the sake of hugeTLB usage reporting, especially since they don't have any use for hugeTLB usage enforcing [2]. 3. Implementation Details: In the alloc / free hugetlb functions, we call lruvec_stat_mod_folio regardless of whether memcg accounts hugetlb. mem_cgroup_commit_charge which is called from alloc_hugetlb_folio will set memcg for the folio only if the CGRP_ROOT_MEMORY_HUGETLB_ACCOUNTING cgroup mount option is used, so lruvec_stat_mod_folio accounts per-memcg hugetlb counters only if the feature is enabled. Regardless of whether memcg accounts for hugetlb, the newly added global counter is updated and shown in /proc/vmstat. The global counter is added because vmstats is the preferred framework for cgroup stats. It makes stat items consistent between global and cgroups. It also provides a per-node breakdown, which is useful. Because it does not use cgroup-specific hooks, we also keep generic MM code separate from memcg code. [1] https://lore.kernel.org/all/20231006184629.155543-1-nphamcs@gmail.com/ [2] Of course, we can't make a new patch for every feature that can be duplicated. However, since the existing solution of enabling the hugeTLB controller is an imperfect solution that still leaves a discrepancy between memory.stat and memory.curent, I think that it is reasonable to isolate the feature in this case. Link: https://lkml.kernel.org/r/20241101204402.1885383-1-joshua.hahnjy@gmail.com Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com> Suggested-by: Nhat Pham <nphamcs@gmail.com> Suggested-by: Shakeel Butt <shakeel.butt@linux.dev> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-11mm: count zeromap read and set for swapout and swapinBarry Song
When the proportion of folios from the zeromap is small, missing their accounting may not significantly impact profiling. However, it's easy to construct a scenario where this becomes an issue—for example, allocating 1 GB of memory, writing zeros from userspace, followed by MADV_PAGEOUT, and then swapping it back in. In this case, the swap-out and swap-in counts seem to vanish into a black hole, potentially causing semantic ambiguity. On the other hand, Usama reported that zero-filled pages can exceed 10% in workloads utilizing zswap, while Hailong noted that some app in Android have more than 6% zero-filled pages. Before commit 0ca0c24e3211 ("mm: store zero pages to be swapped out in a bitmap"), both zswap and zRAM implemented similar optimizations, leading to these optimized-out pages being counted in either zswap or zRAM counters (with pswpin/pswpout also increasing for zRAM). With zeromap functioning prior to both zswap and zRAM, userspace will no longer detect these swap-out and swap-in actions. We have three ways to address this: 1. Introduce a dedicated counter specifically for the zeromap. 2. Use pswpin/pswpout accounting, treating the zero map as a standard backend. This approach aligns with zRAM's current handling of same-page fills at the device level. However, it would mean losing the optimized-out page counters previously available in zRAM and would not align with systems using zswap. Additionally, as noted by Nhat Pham, pswpin/pswpout counters apply only to I/O done directly to the backend device. 3. Count zeromap pages under zswap, aligning with system behavior when zswap is enabled. However, this would not be consistent with zRAM, nor would it align with systems lacking both zswap and zRAM. Given the complications with options 2 and 3, this patch selects option 1. We can find these counters from /proc/vmstat (counters for the whole system) and memcg's memory.stat (counters for the interested memcg). For example: $ grep -E 'swpin_zero|swpout_zero' /proc/vmstat swpin_zero 1648 swpout_zero 33536 $ grep -E 'swpin_zero|swpout_zero' /sys/fs/cgroup/system.slice/memory.stat swpin_zero 3905 swpout_zero 3985 This patch does not address any specific zeromap bug, but the missing swpout and swpin counts for zero-filled pages can be highly confusing and may mislead user-space agents that rely on changes in these counters as indicators. Therefore, we add a Fixes tag to encourage the inclusion of this counter in any kernel versions with zeromap. Many thanks to Kanchana for the contribution of changing count_objcg_event() to count_objcg_events() to support large folios[1], which has now been incorporated into this patch. [1] https://lkml.kernel.org/r/20241001053222.6944-5-kanchana.p.sridhar@intel.com Link: https://lkml.kernel.org/r/20241107011246.59137-1-21cnbao@gmail.com Fixes: 0ca0c24e3211 ("mm: store zero pages to be swapped out in a bitmap") Co-developed-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Hailong Liu <hailong.liu@oppo.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Andi Kleen <ak@linux.intel.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kairui Song <kasong@tencent.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28fs/writeback: convert wbc_account_cgroup_owner to take a folioPankaj Raghav
Most of the callers of wbc_account_cgroup_owner() are converting a folio to page before calling the function. wbc_account_cgroup_owner() is converting the page back to a folio to call mem_cgroup_css_from_folio(). Convert wbc_account_cgroup_owner() to take a folio instead of a page, and convert all callers to pass a folio directly except f2fs. Convert the page to folio for all the callers from f2fs as they were the only callers calling wbc_account_cgroup_owner() with a page. As f2fs is already in the process of converting to folios, these call sites might also soon be calling wbc_account_cgroup_owner() with a folio directly in the future. No functional changes. Only compile tested. Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Link: https://lore.kernel.org/r/20240926140121.203821-1-kernel@pankajraghav.com Acked-by: David Sterba <dsterba@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-21Merge tag 'mm-stable-2024-09-20-02-31' of ↵Linus Torvalds
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 ...
2024-09-18Merge tag 'cgroup-for-6.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - cpuset isolation improvements - cpuset cgroup1 support is split into its own file behind the new config option CONFIG_CPUSET_V1. This makes it the second controller which makes cgroup1 support optional after memcg - Handling of unavailable v1 controller handling improved during cgroup1 mount operations - union_find applied to cpuset. It makes code simpler and more efficient - Reduce spurious events in pids.events - Cleanups and other misc changes - Contains a merge of cgroup/for-6.11-fixes to receive cpuset fixes that further changes build upon * tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (34 commits) cgroup: Do not report unavailable v1 controllers in /proc/cgroups cgroup: Disallow mounting v1 hierarchies without controller implementation cgroup/cpuset: Expose cpuset filesystem with cpuset v1 only cgroup/cpuset: Move cpu.h include to cpuset-internal.h cgroup/cpuset: add sefltest for cpuset v1 cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1 cgroup/cpuset: rename functions shared between v1 and v2 cgroup/cpuset: move v1 interfaces to cpuset-v1.c cgroup/cpuset: move validate_change_legacy to cpuset-v1.c cgroup/cpuset: move legacy hotplug update to cpuset-v1.c cgroup/cpuset: add callback_lock helper cgroup/cpuset: move memory_spread to cpuset-v1.c cgroup/cpuset: move relax_domain_level to cpuset-v1.c cgroup/cpuset: move memory_pressure to cpuset-v1.c cgroup/cpuset: move common code to cpuset-internal.h cgroup/cpuset: introduce cpuset-v1.c selftest/cgroup: Make test_cpuset_prs.sh deal with pre-isolated CPUs cgroup/cpuset: Account for boot time isolated CPUs cgroup/cpuset: remove use_parent_ecpus of cpuset cgroup/cpuset: remove fetch_xcpus ...
2024-09-03Documentation/cgroup-v2: clarify that zswap.writeback is ignored if zswap is ↵Mike Yuan
disabled As discussed in [1], zswap-related settings natually lose their effect when zswap is disabled, specifically zswap.writeback here. Be explicit about this behavior. [1] https://lore.kernel.org/linux-kernel/CAKEwX=Mhbwhh-=xxCU-RjMXS_n=RpV3Gtznb2m_3JgL+jzz++g@mail.gmail.com/ [akpm@linux-foundation.org: fix/simplify text] Link: https://lkml.kernel.org/r/20240823162506.12117-3-me@yhndnzj.com Signed-off-by: Mike Yuan <me@yhndnzj.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03mm,memcg: provide per-cgroup counters for NUMA balancing operationsKaiyang Zhao
The ability to observe the demotion and promotion decisions made by the kernel on a per-cgroup basis is important for monitoring and tuning containerized workloads on machines equipped with tiered memory. Different containers in the system may experience drastically different memory tiering actions that cannot be distinguished from the global counters alone. For example, a container running a workload that has a much hotter memory accesses will likely see more promotions and fewer demotions, potentially depriving a colocated container of top tier memory to such an extent that its performance degrades unacceptably. For another example, some containers may exhibit longer periods between data reuse, causing much more numa_hint_faults than numa_pages_migrated. In this case, tuning hot_threshold_ms may be appropriate, but the signal can easily be lost if only global counters are available. In the long term, we hope to introduce per-cgroup control of promotion and demotion actions to implement memory placement policies in tiering. This patch set adds seven counters to memory.stat in a cgroup: numa_pages_migrated, numa_pte_updates, numa_hint_faults, pgdemote_kswapd, pgdemote_khugepaged, pgdemote_direct and pgpromote_success. pgdemote_* and pgpromote_success are also available in memory.numa_stat. count_memcg_events_mm() is added to count multiple event occurrences at once, and get_mem_cgroup_from_folio() is added because we need to get a reference to the memcg of a folio before it's migrated to track numa_pages_migrated. The accounting of PGDEMOTE_* is moved to shrink_inactive_list() before being changed to per-cgroup. [kaiyang2@cs.cmu.edu: add documentation of the memcg counters in cgroup-v2.rst] Link: https://lkml.kernel.org/r/20240814235122.252309-1-kaiyang2@cs.cmu.edu Link: https://lkml.kernel.org/r/20240814174227.30639-1-kaiyang2@cs.cmu.edu Signed-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu> Cc: David Rientjes <rientjes@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: Wei Xu <weixugc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01mm, memcg: cg2 memory{.swap,}.peak write handlersDavid Finkel
Patch series "mm, memcg: cg2 memory{.swap,}.peak write handlers", v7. This patch (of 2): Other mechanisms for querying the peak memory usage of either a process or v1 memory cgroup allow for resetting the high watermark. Restore parity with those mechanisms, but with a less racy API. For example: - Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets the high watermark. - writing "5" to the clear_refs pseudo-file in a processes's proc directory resets the peak RSS. This change is an evolution of a previous patch, which mostly copied the cgroup v1 behavior, however, there were concerns about races/ownership issues with a global reset, so instead this change makes the reset filedescriptor-local. Writing any non-empty string to the memory.peak and memory.swap.peak pseudo-files reset the high watermark to the current usage for subsequent reads through that same FD. Notably, following Johannes's suggestion, this implementation moves the O(FDs that have written) behavior onto the FD write(2) path. Instead, on the page-allocation path, we simply add one additional watermark to conditionally bump per-hierarchy level in the page-counter. Additionally, this takes Longman's suggestion of nesting the page-charging-path checks for the two watermarks to reduce the number of common-case comparisons. This behavior is particularly useful for work scheduling systems that need to track memory usage of worker processes/cgroups per-work-item. Since memory can't be squeezed like CPU can (the OOM-killer has opinions), these systems need to track the peak memory usage to compute system/container fullness when binpacking workitems. Most notably, Vimeo's use-case involves a system that's doing global binpacking across many Kubernetes pods/containers, and while we can use PSI for some local decisions about overload, we strive to avoid packing workloads too tightly in the first place. To facilitate this, we track the peak memory usage. However, since we run with long-lived workers (to amortize startup costs) we need a way to track the high watermark while a work-item is executing. Polling runs the risk of missing short spikes that last for timescales below the polling interval, and peak memory tracking at the cgroup level is otherwise perfect for this use-case. As this data is used to ensure that binpacked work ends up with sufficient headroom, this use-case mostly avoids the inaccuracies surrounding reclaimable memory. Link: https://lkml.kernel.org/r/20240730231304.761942-1-davidf@vimeo.com Link: https://lkml.kernel.org/r/20240729143743.34236-1-davidf@vimeo.com Link: https://lkml.kernel.org/r/20240729143743.34236-2-davidf@vimeo.com Signed-off-by: David Finkel <davidf@vimeo.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Waiman Long <longman@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Koutný <mkoutny@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shuah Khan <shuah@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01mm/memcontrol: respect zswap.writeback setting from parent cg tooMike Yuan
Currently, the behavior of zswap.writeback wrt. the cgroup hierarchy seems a bit odd. Unlike zswap.max, it doesn't honor the value from parent cgroups. This surfaced when people tried to globally disable zswap writeback, i.e. reserve physical swap space only for hibernation [1] - disabling zswap.writeback only for the root cgroup results in subcgroups with zswap.writeback=1 still performing writeback. The inconsistency became more noticeable after I introduced the MemoryZSwapWriteback= systemd unit setting [2] for controlling the knob. The patch assumed that the kernel would enforce the value of parent cgroups. It could probably be workarounded from systemd's side, by going up the slice unit tree and inheriting the value. Yet I think it's more sensible to make it behave consistently with zswap.max and friends. [1] https://wiki.archlinux.org/title/Power_management/Suspend_and_hibernate#Disable_zswap_writeback_to_use_the_swap_space_only_for_hibernation [2] https://github.com/systemd/systemd/pull/31734 Link: https://lkml.kernel.org/r/20240823162506.12117-1-me@yhndnzj.com Fixes: 501a06fe8e4c ("zswap: memcontrol: implement zswap writeback disabling") Signed-off-by: Mike Yuan <me@yhndnzj.com> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Yosry Ahmed <yosryahmed@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-19cgroup: update some statememt about delegationChen Ridong
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>
2024-07-31cgroup: Show # of subsystem CSSes in cgroup.statWaiman Long
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>
2024-07-21Merge tag 'mm-stable-2024-07-21-14-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc/<pid>/maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...
2024-07-12cgroup/misc: Introduce misc.events.localXiu Jianfeng
Currently the event counting provided by misc.events is hierarchical, it's not practical if user is only concerned with events of a specified cgroup. Therefore, introduce misc.events.local collect events specific to the given cgroup. This is analogous to memory.events.local and pids.events.local. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-04mm: add swappiness= arg to memory.reclaimDan Schatzberg
Allow proactive reclaimers to submit an additional swappiness=<val> argument to memory.reclaim. This overrides the global or per-memcg swappiness setting for that reclaim attempt. For example: echo "2M swappiness=0" > /sys/fs/cgroup/memory.reclaim will perform reclaim on the rootcg with a swappiness setting of 0 (no swap) regardless of the vm.swappiness sysctl setting. Userspace proactive reclaimers use the memory.reclaim interface to trigger reclaim. The memory.reclaim interface does not allow for any way to effect the balance of file vs anon during proactive reclaim. The only approach is to adjust the vm.swappiness setting. However, there are a few reasons we look to control the balance of file vs anon during proactive reclaim, separately from reactive reclaim: * Swapout should be limited to manage SSD write endurance. In near-OOM situations we are fine with lots of swap-out to avoid OOMs. As these are typically rare events, they have relatively little impact on write endurance. However, proactive reclaim runs continuously and so its impact on SSD write endurance is more significant. Therefore it is desireable to control swap-out for proactive reclaim separately from reactive reclaim * Some userspace OOM killers like systemd-oomd[1] support OOM killing on swap exhaustion. This makes sense if the swap exhaustion is triggered due to reactive reclaim but less so if it is triggered due to proactive reclaim (e.g. one could see OOMs when free memory is ample but anon is just particularly cold). Therefore, it's desireable to have proactive reclaim reduce or stop swap-out before the threshold at which OOM killing occurs. In the case of Meta's Senpai proactive reclaimer, we adjust vm.swappiness before writes to memory.reclaim[2]. This has been in production for nearly two years and has addressed our needs to control proactive vs reactive reclaim behavior but is still not ideal for a number of reasons: * vm.swappiness is a global setting, adjusting it can race/interfere with other system administration that wishes to control vm.swappiness. In our case, we need to disable Senpai before adjusting vm.swappiness. * vm.swappiness is stateful - so a crash or restart of Senpai can leave a misconfigured setting. This requires some additional management to record the "desired" setting and ensure Senpai always adjusts to it. With this patch, we avoid these downsides of adjusting vm.swappiness globally. [1]https://www.freedesktop.org/software/systemd/man/latest/systemd-oomd.service.html [2]https://github.com/facebookincubator/oomd/blob/main/src/oomd/plugins/Senpai.cpp#L585-L598 Link: https://lkml.kernel.org/r/20240103164841.2800183-3-schatzberg.dan@gmail.com Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com> Suggested-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Yue Zhao <findns94@gmail.com> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03cgroup/misc: Introduce misc.peakXiu Jianfeng
Introduce misc.peak to record the historical maximum usage of the resource, as in some scenarios the value of misc.max could be adjusted based on the peak usage of the resource. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-06-19cgroup/cpuset: Make cpuset.cpus.exclusive independent of cpuset.cpusWaiman Long
The "cpuset.cpus.exclusive.effective" value is currently limited to a subset of its "cpuset.cpus". This makes the exclusive CPUs distribution hierarchy subsumed within the larger "cpuset.cpus" hierarchy. We have to decide on what CPUs are used locally and what CPUs can be passed down as exclusive CPUs down the hierarchy and combine them into "cpuset.cpus". The advantage of the current scheme is to have only one hierarchy to worry about. However, it make it harder to use as all the "cpuset.cpus" values have to be properly set along the way down to the designated remote partition root. It also makes it more cumbersome to find out what CPUs can be used locally. Make creation of remote partition simpler by breaking the dependency of "cpuset.cpus.exclusive" on "cpuset.cpus" and make them independent entities. Now we have two separate hierarchies - one for setting "cpuset.cpus.effective" and the other one for setting "cpuset.cpus.exclusive.effective". We may not need to set "cpuset.cpus" when we activate a partition root anymore. Also update Documentation/admin-guide/cgroup-v2.rst and cpuset.c comment to document this change. Suggested-by: Petr Malat <oss@malat.biz> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-06-19cgroup/cpuset: Delay setting of CS_CPU_EXCLUSIVE until valid partitionWaiman Long
The CS_CPU_EXCLUSIVE flag is currently set whenever cpuset.cpus.exclusive is set to make sure that the exclusivity test will be run to ensure its exclusiveness. At the same time, this flag can be changed whenever the partition root state is changed. For example, the CS_CPU_EXCLUSIVE flag will be reset whenever a partition root becomes invalid. This makes using CS_CPU_EXCLUSIVE to ensure exclusiveness a bit fragile. The current scheme also makes setting up a cpuset.cpus.exclusive hierarchy to enable remote partition harder as cpuset.cpus.exclusive cannot overlap with any cpuset.cpus of sibling cpusets if their cpuset.cpus.exclusive aren't set. Solve these issues by deferring the setting of CS_CPU_EXCLUSIVE flag until the cpuset become a valid partition root while adding new checks in validate_change() to ensure that cpuset.cpus.exclusive of sibling cpusets cannot overlap. An additional check is also added to validate_change() to make sure that cpuset.cpus of one cpuset cannot be a subset of cpuset.cpus.exclusive of a sibling cpuset to avoid the problem that none of those CPUs will be available when these exclusive CPUs are extracted out to a newly enabled partition root. The Documentation/admin-guide/cgroup-v2.rst file is updated to document the new constraints. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-05-26cgroup/pids: Add pids.events.localMichal Koutný
Hierarchical counting of events is not practical for watching when a particular pids.max is being hit. Therefore introduce .local flavor of events file (akin to memory controller) that collects only events relevant to given cgroup. The file is only added to the default hierarchy. Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-05-26cgroup/pids: Make event counters hierarchicalMichal Koutný
The pids.events file should honor the hierarchy, so make the events propagate from their origin up to the root on the unified hierarchy. The legacy behavior remains non-hierarchical. Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-05-26cgroup/pids: Separate semantics of pids.events related to pids.maxMichal Koutný
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>
2024-05-18Merge tag 'iommu-updates-v6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu updates from Joerg Roedel: "Core: - IOMMU memory usage observability - This will make the memory used for IO page tables explicitly visible. - Simplify arch_setup_dma_ops() Intel VT-d: - Consolidate domain cache invalidation - Remove private data from page fault message - Allocate DMAR fault interrupts locally - Cleanup and refactoring ARM-SMMUv2: - Support for fault debugging hardware on Qualcomm implementations - Re-land support for the ->domain_alloc_paging() callback ARM-SMMUv3: - Improve handling of MSI allocation failure - Drop support for the "disable_bypass" cmdline option - Major rework of the CD creation code, following on directly from the STE rework merged last time around. - Add unit tests for the new STE/CD manipulation logic AMD-Vi: - Final part of SVA changes with generic IO page fault handling Renesas IPMMU: - Add support for R8A779H0 hardware ... and a couple smaller fixes and updates across the sub-tree" * tag 'iommu-updates-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (80 commits) iommu/arm-smmu-v3: Make the kunit into a module arm64: Properly clean up iommu-dma remnants iommu/amd: Enable Guest Translation after reading IOMMU feature register iommu/vt-d: Decouple igfx_off from graphic identity mapping iommu/amd: Fix compilation error iommu/arm-smmu-v3: Add unit tests for arm_smmu_write_entry iommu/arm-smmu-v3: Build the whole CD in arm_smmu_make_s1_cd() iommu/arm-smmu-v3: Move the CD generation for SVA into a function iommu/arm-smmu-v3: Allocate the CD table entry in advance iommu/arm-smmu-v3: Make arm_smmu_alloc_cd_ptr() iommu/arm-smmu-v3: Consolidate clearing a CD table entry iommu/arm-smmu-v3: Move the CD generation for S1 domains into a function iommu/arm-smmu-v3: Make CD programming use arm_smmu_write_entry() iommu/arm-smmu-v3: Add an ops indirection to the STE code iommu/arm-smmu-qcom: Don't build debug features as a kernel module iommu/amd: Add SVA domain support iommu: Add ops->domain_alloc_sva() iommu/amd: Initial SVA support for AMD IOMMU iommu/amd: Add support for enable/disable IOPF iommu/amd: Add IO page fault notifier handler ...
2024-05-15Merge tag 'cgroup-for-6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - The locking around cpuset hotplug processing has always been a bit of mess which was worked around by making hotplug processing asynchronous. The asynchronity isn't great and led to other issues. We tried to make the behavior synchronous a while ago but that led to lockdep splats. Waiman took another stab at cleaning up and making it synchronous. The patch has been in -next for well over a month and there haven't been any complaints, so fingers crossed. - Tracepoints added to help understanding rstat lock contentions. - A bunch of minor changes - doc updates, code cleanups and selftests. * tag 'cgroup-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (24 commits) cgroup/rstat: add cgroup_rstat_cpu_lock helpers and tracepoints selftests/cgroup: Drop define _GNU_SOURCE docs: cgroup-v1: Update page cache removal functions selftests/cgroup: fix uninitialized variables in test_zswap.c selftests/cgroup: cpu_hogger init: use {} instead of {NULL} selftests/cgroup: fix clang warnings: uninitialized fd variable selftests/cgroup: fix clang build failures for abs() calls cgroup/cpuset: Remove outdated comment in sched_partition_write() cgroup/cpuset: Fix incorrect top_cpuset flags cgroup/cpuset: Avoid clearing CS_SCHED_LOAD_BALANCE twice cgroup/cpuset: Statically initialize more members of top_cpuset cgroup: Avoid unnecessary looping in cgroup_no_v1() cgroup, legacy_freezer: update comment for freezer_css_offline() docs, cgroup: add entries for pids to cgroup-v2.rst cgroup: don't call cgroup1_pidlist_destroy_all() for v2 cgroup_freezer: update comment for freezer_css_online() cgroup/rstat: desc member cgrp in cgroup_rstat_flush_release cgroup/rstat: add cgroup_rstat_lock helpers and tracepoints cgroup/pids: Remove superfluous zeroing docs: cgroup-v1: Fix description for css_online ...
2024-05-09cgroup: Add documentation for missing zswap memory.statUsama Arif
This includes zswpin, zswpout and zswpwb. Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20240502185307.3942173-2-usamaarif642@gmail.com>
2024-04-18docs, cgroup: add entries for pids to cgroup-v2.rstXiu Jianfeng
This patch add two entries (pids.peak and pids.events) for pids controller, and also update pids.current because it's on non-root. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-04-15iommu: account IOMMU allocated memoryPasha Tatashin
In order to be able to limit the amount of memory that is allocated by IOMMU subsystem, the memory must be accounted. Account IOMMU as part of the secondary pagetables as it was discussed at LPC. The value of SecPageTables now contains mmeory allocation by IOMMU and KVM. There is a difference between GFP_ACCOUNT and what NR_IOMMU_PAGES shows. GFP_ACCOUNT is set only where it makes sense to charge to user processes, i.e. IOMMU Page Tables, but there more IOMMU shared data that should not really be charged to a specific process. Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: David Rientjes <rientjes@google.com> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20240413002522.1101315-12-pasha.tatashin@soleen.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-03-25cgroup, docs: Clarify limitation of RT processes with cgroup v2 cpu controllerWaiman Long
The limitation that all RT processes have to be in the root cgroup before enabling cpu controller only applies if the CONFIG_RT_GROUP_SCHED option is enabled in the running kernel. If a kernel does not have CONFIG_RT_GROUP_SCHED enabled, RT processes can exist in a non-root cgroup even when cpu controller is enabled. CPU sharing of RT processes will not be under cgroup control, but other resources like memory can be. Clarify this limitation to avoid confusion to users that are using cgroup v2. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-01-09Merge tag 'mm-stable-2024-01-08-15-31' of ↵Linus Torvalds
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: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...