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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-20 08:15:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-20 08:15:23 -0700
commitbdab18633a302c82b5e5d5dbc4e38b0baf9c0837 (patch)
tree0446500af9a76d4e8b2a72a0a41391ceede73a10 /Documentation/ABI/testing/sysfs-kernel-mm-numa
downloadlinux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.tar.gz
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Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted
Pull futex fix from Ingo Molnar: - Also allocate a default private futex hash on vfork() as well, to avoid races with (private) futex waiters (Peter Zijlstra) * tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Also allocate private hash on vfork()
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+What: /sys/kernel/mm/numa/
+Date: June 2021
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Interface for NUMA
+
+What: /sys/kernel/mm/numa/demotion_enabled
+Date: June 2021
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Enable/disable demoting pages during reclaim
+
+ Page migration during reclaim is intended for systems
+ with tiered memory configurations. These systems have
+ multiple types of memory with varied performance
+ characteristics instead of plain NUMA systems where
+ the same kind of memory is found at varied distances.
+ Allowing page migration during reclaim enables these
+ systems to migrate pages from fast tiers to slow tiers
+ when the fast tier is under pressure. This migration
+ is performed before swap if an eligible numa node is
+ present in cpuset.mems for the cgroup (or if cpuset v1
+ is being used). If cpusets.mems changes at runtime, it
+ may move data to a NUMA node that does not fall into the
+ cpuset of the new cpusets.mems, which might be construed
+ to violate the guarantees of cpusets. Shared memory,
+ such as libraries, owned by another cgroup may still be
+ demoted and result in memory use on a node not present
+ in cpusets.mem. This should not be enabled on systems
+ which need strict cpuset location guarantees.