0001 What: /sys/kernel/mm/numa/
0002 Date: June 2021
0003 Contact: Linux memory management mailing list <linux-mm@kvack.org>
0004 Description: Interface for NUMA
0005
0006 What: /sys/kernel/mm/numa/demotion_enabled
0007 Date: June 2021
0008 Contact: Linux memory management mailing list <linux-mm@kvack.org>
0009 Description: Enable/disable demoting pages during reclaim
0010
0011 Page migration during reclaim is intended for systems
0012 with tiered memory configurations. These systems have
0013 multiple types of memory with varied performance
0014 characteristics instead of plain NUMA systems where
0015 the same kind of memory is found at varied distances.
0016 Allowing page migration during reclaim enables these
0017 systems to migrate pages from fast tiers to slow tiers
0018 when the fast tier is under pressure. This migration
0019 is performed before swap. It may move data to a NUMA
0020 node that does not fall into the cpuset of the
0021 allocating process which might be construed to violate
0022 the guarantees of cpusets. This should not be enabled
0023 on systems which need strict cpuset location
0024 guarantees.
