| 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. It may move data to a NUMA | |
| node that does not fall into the cpuset of the | |
| allocating process which might be construed to violate | |
| the guarantees of cpusets. This should not be enabled | |
| on systems which need strict cpuset location | |
| guarantees. |