]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
Allow huge page allocations to use GFP_HIGH_MOVABLE
authorMel Gorman <mel@csn.ul.ie>
Tue, 17 Jul 2007 11:03:13 +0000 (04:03 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 17 Jul 2007 17:22:59 +0000 (10:22 -0700)
commit396faf0303d273219db5d7eb4a2879ad977ed185
tree96cb64fd6713ef7a924f4f878e259aea781f079a
parent2a1e274acf0b1c192face19a4be7c12d4503eaaf
Allow huge page allocations to use GFP_HIGH_MOVABLE

Huge pages are not movable so are not allocated from ZONE_MOVABLE.  However,
as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
can be used to satisfy hugepage allocations even when the system has been
running a long time.  This allows an administrator to resize the hugepage pool
at runtime depending on the size of ZONE_MOVABLE.

This patch adds a new sysctl called hugepages_treat_as_movable.  When a
non-zero value is written to it, future allocations for the huge page pool
will use ZONE_MOVABLE.  Despite huge pages being non-movable, we do not
introduce additional external fragmentation of note as huge pages are always
the largest contiguous block we care about.

[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/hugetlb.h
include/linux/mempolicy.h
kernel/sysctl.c
mm/hugetlb.c
mm/mempolicy.c