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| author | Mel Gorman <mel@csn.ul.ie> | 2007-07-17 04:03:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-17 10:22:59 -0700 |
| commit | 396faf0303d273219db5d7eb4a2879ad977ed185 (patch) | |
| tree | 96cb64fd6713ef7a924f4f878e259aea781f079a /kernel/sysctl.c | |
| parent | 2a1e274acf0b1c192face19a4be7c12d4503eaaf (diff) | |
| download | lwn-396faf0303d273219db5d7eb4a2879ad977ed185.tar.gz lwn-396faf0303d273219db5d7eb4a2879ad977ed185.zip | |
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>
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2ce7acf841ae..48dae075d5c2 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -826,6 +826,14 @@ static ctl_table vm_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "hugepages_treat_as_movable", + .data = &hugepages_treat_as_movable, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &hugetlb_treat_movable_handler, + }, #endif { .ctl_name = VM_LOWMEM_RESERVE_RATIO, |