admin-guide/sysctl/vm.rst

282 reclaim to satisfy a high-order allocation. The extfrag/extfrag_index file in
315 where background reclaim (kswapd) kicks in, and the threshold where direct
316 reclaim (by allocating processes) kicks in.
322 size of 200MB may need 200MB of extra free memory to avoid direct reclaim
510 A percentage of the total pages in each zone.  On Zone reclaim
514 systems that rarely perform global reclaim.
518 Note that slab reclaim is triggered in a per zone / node fashion.
528 This is a percentage of the total pages in each zone. Zone reclaim will
927 This percentage value controls the tendency of the kernel to reclaim
931 reclaim dentries and inodes at a "fair" rate with respect to pagecache and
932 swapcache reclaim.  Decreasing vfs_cache_pressure causes the kernel to prefer
934 never reclaim dentries and inodes due to memory pressure and this can easily
936 causes the kernel to prefer to reclaim dentries and inodes.
947 This factor controls the level of reclaim when memory is being fragmented.
958 to fragmentation. The level of reclaim is determined by the number of
975 A high rate of threads entering direct reclaim (allocstall) or kswapd
986 reclaim memory when a zone runs out of memory. If it is set to zero then no
987 zone reclaim occurs. Allocations will be satisfied from other zones / nodes
993 1	Zone reclaim on
994 2	Zone reclaim writes dirty pages out
995 4	Zone reclaim swaps pages
1009 Allowing zone reclaim to write out pages stops processes that are
1011 reclaim will write out dirty pages if a zone fills up and so effectively