kernel/linux.git/include/linux/cpuset.h, branch v7.0-rc7

Merge tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-19T04:50:32+00:00

Pull more MM updates from Andrew Morton: - "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a couple of issues in the demotion code - pages were failed demotion and were finding themselves demoted into disallowed nodes (Bing Jiao) - "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare mapledtree race and performs a number of cleanups (Liam Howlett) - "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them" implements a lot of cleanups following on from the conversion of the VMA flags into a bitmap (Lorenzo Stoakes) - "support batch checking of references and unmapping for large folios" implements batching to greatly improve the performance of reclaiming clean file-backed large folios (Baolin Wang) - "selftests/mm: add memory failure selftests" does as claimed (Miaohe Lin) * tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits) mm/page_alloc: clear page->private in free_pages_prepare() selftests/mm: add memory failure dirty pagecache test selftests/mm: add memory failure clean pagecache test selftests/mm: add memory failure anonymous page test mm: rmap: support batched unmapping for file large folios arm64: mm: implement the architecture-specific clear_flush_young_ptes() arm64: mm: support batch clearing of the young flag for large folios arm64: mm: factor out the address and ptep alignment into a new helper mm: rmap: support batched checks of the references for large folios tools/testing/vma: add VMA userland tests for VMA flag functions tools/testing/vma: separate out vma_internal.h into logical headers tools/testing/vma: separate VMA userland tests into separate files mm: make vm_area_desc utilise vma_flags_t only mm: update all remaining mmap_prepare users to use vma_flags_t mm: update shmem_[kernel]_file_*() functions to use vma_flags_t mm: update secretmem to use VMA flags on mmap_prepare mm: update hugetlbfs to use VMA flags on mmap_prepare mm: add basic VMA flag operation helper functions tools: bitmap: add missing bitmap_[subset(), andnot()] mm: add mk_vma_flags() bitmap flag macro helper ...

mm/vmscan: fix demotion targets checks in reclaim/demotion

2026-02-12T23:42:52+00:00

Patch series "mm/vmscan: fix demotion targets checks in reclaim/demotion", v9. This patch series addresses two issues in demote_folio_list(), can_demote(), and next_demotion_node() in reclaim/demotion. 1. demote_folio_list() and can_demote() do not correctly check demotion target against cpuset.mems_effective, which will cause (a) pages to be demoted to not-allowed nodes and (b) pages fail demotion even if the system still has allowed demotion nodes. Patch 1 fixes this bug by updating cpuset_node_allowed() and mem_cgroup_node_allowed() to return effective_mems, allowing directly logic-and operation against demotion targets. 2. next_demotion_node() returns a preferred demotion target, but it does not check the node against allowed nodes. Patch 2 ensures that next_demotion_node() filters against the allowed node mask and selects the closest demotion target to the source node. This patch (of 2): Fix two bugs in demote_folio_list() and can_demote() due to incorrect demotion target checks against cpuset.mems_effective in reclaim/demotion. Commit 7d709f49babc ("vmscan,cgroup: apply mems_effective to reclaim") introduces the cpuset.mems_effective check and applies it to can_demote(). However: 1. It does not apply this check in demote_folio_list(), which leads to situations where pages are demoted to nodes that are explicitly excluded from the task's cpuset.mems. 2. It checks only the nodes in the immediate next demotion hierarchy and does not check all allowed demotion targets in can_demote(). This can cause pages to never be demoted if the nodes in the next demotion hierarchy are not set in mems_effective. These bugs break resource isolation provided by cpuset.mems. This is visible from userspace because pages can either fail to be demoted entirely or are demoted to nodes that are not allowed in multi-tier memory systems. To address these bugs, update cpuset_node_allowed() and mem_cgroup_node_allowed() to return effective_mems, allowing directly logic-and operation against demotion targets. Also update can_demote() and demote_folio_list() accordingly. Bug 1 reproduction: Assume a system with 4 nodes, where nodes 0-1 are top-tier and nodes 2-3 are far-tier memory. All nodes have equal capacity. Test script: echo 1 > /sys/kernel/mm/numa/demotion_enabled mkdir /sys/fs/cgroup/test echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control echo "0-2" > /sys/fs/cgroup/test/cpuset.mems echo $$ > /sys/fs/cgroup/test/cgroup.procs swapoff -a # Expectation: Should respect node 0-2 limit. # Observation: Node 3 shows significant allocation (MemFree drops) stress-ng --oomable --vm 1 --vm-bytes 150% --mbind 0,1 Bug 2 reproduction: Assume a system with 6 nodes, where nodes 0-2 are top-tier, node 3 is a far-tier node, and nodes 4-5 are the farthest-tier nodes. All nodes have equal capacity. Test script: echo 1 > /sys/kernel/mm/numa/demotion_enabled mkdir /sys/fs/cgroup/test echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control echo "0-2,4-5" > /sys/fs/cgroup/test/cpuset.mems echo $$ > /sys/fs/cgroup/test/cgroup.procs swapoff -a # Expectation: Pages are demoted to Nodes 4-5 # Observation: No pages are demoted before oom. stress-ng --oomable --vm 1 --vm-bytes 150% --mbind 0,1,2 Link: https://lkml.kernel.org/r/20260114205305.2869796-1-bingjiao@google.com Link: https://lkml.kernel.org/r/20260114205305.2869796-2-bingjiao@google.com Fixes: 7d709f49babc ("vmscan,cgroup: apply mems_effective to reclaim") Signed-off-by: Bing Jiao Acked-by: Shakeel Butt Cc: Axel Rasmussen Cc: David Hildenbrand Cc: Gregory Price Cc: Johannes Weiner Cc: Joshua Hahn Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Qi Zheng Cc: Roman Gushchin Cc: Suren Baghdasaryan Cc: Tejun Heo Cc: Vlastimil Babka Cc: Waiman Long Cc: Wei Xu Cc: Yuanchu Xie Cc: Signed-off-by: Andrew Morton

Merge tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2026-02-11T21:20:50+00:00

Pull cgroup updates from Tejun Heo: - cpuset changes: - Continue separating v1 and v2 implementations by moving more v1-specific logic into cpuset-v1.c - Improve partition handling. Sibling partitions are no longer invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer fail in v2, and effective_xcpus computation is made consistent - Fix partition effective CPUs overlap that caused a warning on cpuset removal when sibling partitions shared CPUs - Increase the maximum cgroup subsystem count from 16 to 32 to accommodate future subsystem additions - Misc cleanups and selftest improvements including switching to css_is_online() helper, removing dead code and stale documentation references, using lockdep_assert_cpuset_lock_held() consistently, and adding polling helpers for asynchronously updated cgroup statistics * tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cpuset: fix overlap of partition effective CPUs cgroup: increase maximum subsystem count from 16 to 32 cgroup: Remove stale cpu.rt.max reference from documentation cpuset: replace direct lockdep_assert_held() with lockdep_assert_cpuset_lock_held() cgroup/cpuset: Move the v1 empty cpus/mems check to cpuset1_validate_change() cgroup/cpuset: Don't invalidate sibling partitions on cpuset.cpus conflict cgroup/cpuset: Don't fail cpuset.cpus change in v2 cgroup/cpuset: Consistently compute effective_xcpus in update_cpumasks_hier() cgroup/cpuset: Streamline rm_siblings_excl_cpus() cpuset: remove dead code in cpuset-v1.c cpuset: remove v1-specific code from generate_sched_domains cpuset: separate generate_sched_domains for v1 and v2 cpuset: move update_domain_attr_tree to cpuset_v1.c cpuset: add cpuset1_init helper for v1 initialization cpuset: add cpuset1_online_css helper for v1-specific operations cpuset: add lockdep_assert_cpuset_lock_held helper cpuset: Remove unnecessary checks in rebuild_sched_domains_locked cgroup: switch to css_is_online() helper selftests: cgroup: Replace sleep with cg_read_key_long_poll() for waiting on nr_dying_descendants selftests: cgroup: make test_memcg_sock robust against delayed sock stats ...

cpuset: Remove cpuset_cpu_is_isolated()

2026-02-03T14:23:34+00:00

The set of cpuset isolated CPUs is now included in HK_TYPE_DOMAIN housekeeping cpumask. There is no usecase left interested in just checking what is isolated by cpuset and not by the isolcpus= kernel boot parameter. Signed-off-by: Frederic Weisbecker Reviewed-by: Waiman Long Cc: "Michal Koutný" Cc: Johannes Weiner Cc: Marco Crivellari Cc: Michal Hocko Cc: Peter Zijlstra Cc: Tejun Heo Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Waiman Long Cc: cgroups@vger.kernel.org

cpuset: Provide lockdep check for cpuset lock held

2026-02-03T14:23:33+00:00

cpuset modifies partitions, including isolated, while holding the cpuset mutex. This means that holding the cpuset mutex is safe to synchronize against housekeeping cpumask changes. Provide a lockdep check to validate that. Signed-off-by: Frederic Weisbecker Cc: "Michal Koutný" Cc: Johannes Weiner Cc: Marco Crivellari Cc: Michal Hocko Cc: Peter Zijlstra Cc: Tejun Heo Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Waiman Long Cc: cgroups@vger.kernel.org Cc: linux-kernel@vger.kernel.org

cpuset: add lockdep_assert_cpuset_lock_held helper

2025-12-18T18:35:57+00:00

Add lockdep_assert_cpuset_lock_held() to allow other subsystems to verify that cpuset_mutex is held. Suggested-by: Waiman Long Signed-off-by: Chen Ridong Reviewed-by: Waiman Long Signed-off-by: Tejun Heo

cgroup/cpuset: Introduce cpuset_cpus_allowed_locked()

2025-11-20T16:57:58+00:00

cpuset_cpus_allowed() uses a reader lock that is sleepable under RT, which means it cannot be called inside raw_spin_lock_t context. Introduce a new cpuset_cpus_allowed_locked() helper that performs the same function as cpuset_cpus_allowed() except that the caller must have acquired the cpuset_mutex so that no further locking will be needed. Suggested-by: Waiman Long Signed-off-by: Pingfan Liu Cc: Waiman Long Cc: Tejun Heo Cc: Johannes Weiner Cc: Michal Koutný Cc: linux-kernel@vger.kernel.org To: cgroups@vger.kernel.org Reviewed-by: Chen Ridong Reviewed-by: Waiman Long Signed-off-by: Tejun Heo

vmscan,cgroup: apply mems_effective to reclaim

2025-05-13T06:50:33+00:00

It is possible for a reclaimer to cause demotions of an lruvec belonging to a cgroup with cpuset.mems set to exclude some nodes. Attempt to apply this limitation based on the lruvec's memcg and prevent demotion. Notably, this may still allow demotion of shared libraries or any memory first instantiated in another cgroup. This means cpusets still cannot cannot guarantee complete isolation when demotion is enabled, and the docs have been updated to reflect this. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently - with the noted exceptions. Note on locking: The cgroup_get_e_css reference protects the css->effective_mems, and calls of this interface would be subject to the same race conditions associated with a non-atomic access to cs->effective_mems. So while this interface cannot make strong guarantees of correctness, it can therefore avoid taking a global or rcu_read_lock for performance. Link: https://lkml.kernel.org/r/20250424202806.52632-3-gourry@gourry.net Signed-off-by: Gregory Price Suggested-by: Shakeel Butt Suggested-by: Waiman Long Acked-by: Tejun Heo Acked-by: Johannes Weiner Reviewed-by: Shakeel Butt Reviewed-by: Waiman Long Cc: Michal Hocko Cc: Michal Koutný Cc: Muchun Song Cc: Roman Gushchin Signed-off-by: Andrew Morton

cpuset: rename cpuset_node_allowed to cpuset_current_node_allowed

2025-05-13T06:50:33+00:00

Patch series "vmscan: enforce mems_effective during demotion", v5. Change reclaim to respect cpuset.mems_effective during demotion when possible. Presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. Implement cpuset_node_allowed() to check the cpuset.mems_effective associated wih the mem_cgroup of the lruvec being scanned. This only applies to cgroup/cpuset v2, as cpuset exists in a different hierarchy than mem_cgroup in v1. This requires renaming the existing cpuset_node_allowed() to be cpuset_current_now_allowed() - which is more descriptive anyway - to implement the new cpuset_node_allowed() which takes a target cgroup. This patch (of 2): Rename cpuset_node_allowed to reflect that the function checks the current task's cpuset.mems. This allows us to make a new cpuset_node_allowed function that checks a target cgroup's cpuset.mems. Link: https://lkml.kernel.org/r/20250424202806.52632-1-gourry@gourry.net Link: https://lkml.kernel.org/r/20250424202806.52632-2-gourry@gourry.net Signed-off-by: Gregory Price Acked-by: Waiman Long Acked-by: Tejun Heo Acked-by: Johannes Weiner Reviewed-by: Shakeel Butt Cc: Michal Hocko Cc: Michal Koutný Cc: Muchun Song Cc: Roman Gushchin Signed-off-by: Andrew Morton

include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h

2025-03-17T10:23:43+00:00

dl_rebuild_rd_accounting() is defined in cpuset.c, so it makes more sense to move related declarations to cpuset.h. Implement the move. Suggested-by: Waiman Long Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Waiman Long Reviewed-by: Valentin Schneider Reviewed-by: Dietmar Eggemann Tested-by: Waiman Long Tested-by: Jon Hunter Tested-by: Dietmar Eggemann Link: https://lore.kernel.org/r/Z9MSOVMpU7jpVrMU@jlelli-thinkpadt14gen4.remote.csb