mm, page_alloc: cache pageset high and batch in struct zone
authorVlastimil Babka <vbabka@suse.cz>
Tue, 15 Dec 2020 03:10:53 +0000 (19:10 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 15 Dec 2020 20:13:43 +0000 (12:13 -0800)
commit952eaf815925f106eb6b68346b3458a68bb18ec1
tree7c66b4fd4dfd320f88749320152b9d1029a2855c
parent5c3ad2eb7104754a36580079a2e4aed04a10631d
mm, page_alloc: cache pageset high and batch in struct zone

All per-cpu pagesets for a zone use the same high and batch values, that
are duplicated there just for performance (locality) reasons.  This patch
adds the same variables also to struct zone as a shared copy.

This will be useful later for making possible to disable pcplists
temporarily by setting high value to 0, while remembering the values for
restoring them later.  But we can also immediately benefit from not
updating pagesets of all possible cpus in case the newly recalculated
values (after sysctl change or memory online/offline) are actually
unchanged from the previous ones.

Link: https://lkml.kernel.org/r/20201111092812.11329-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/mmzone.h
mm/page_alloc.c