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Diffstat (limited to 'Documentation/ABI/testing/sysfs-kernel-mm-numa')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-mm-numa | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-numa b/Documentation/ABI/testing/sysfs-kernel-mm-numa new file mode 100644 index 000000000000..90e375ff54cb --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-mm-numa @@ -0,0 +1,28 @@ +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. |