diff options
| -rw-r--r-- | Documentation/admin-guide/sysctl/vm.rst | 10 | ||||
| -rw-r--r-- | mm/vmscan.c | 9 |
2 files changed, 12 insertions, 7 deletions
diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index e35a3f2fb006..586cd4b86428 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -983,11 +983,11 @@ that benefit from having their data cached, zone_reclaim_mode should be left disabled as the caching effect is likely to be more important than data locality. -zone_reclaim may be enabled if it's known that the workload is partitioned -such that each partition fits within a NUMA node and that accessing remote -memory would cause a measurable performance reduction. The page allocator -will then reclaim easily reusable pages (those page cache pages that are -currently not used) before allocating off node pages. +Consider enabling one or more zone_reclaim mode bits if it's known that the +workload is partitioned such that each partition fits within a NUMA node +and that accessing remote memory would cause a measurable performance +reduction. The page allocator will take additional actions before +allocating off node pages. Allowing zone reclaim to write out pages stops processes that are writing large amounts of data from dirtying pages on other nodes. Zone diff --git a/mm/vmscan.c b/mm/vmscan.c index fea6b43bc1f9..562e87cbd7a1 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4085,8 +4085,13 @@ module_init(kswapd_init) */ int node_reclaim_mode __read_mostly; -#define RECLAIM_WRITE (1<<0) /* Writeout pages during reclaim */ -#define RECLAIM_UNMAP (1<<1) /* Unmap pages during reclaim */ +/* + * These bit locations are exposed in the vm.zone_reclaim_mode sysctl + * ABI. New bits are OK, but existing bits can never change. + */ +#define RECLAIM_ZONE (1<<0) /* Run shrink_inactive_list on the zone */ +#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */ +#define RECLAIM_UNMAP (1<<2) /* Unmap pages during reclaim */ /* * Priority for NODE_RECLAIM. This determines the fraction of pages |