mm: page_alloc: rearrange watermark checking in get_page_from_freelist
Allocations that do not have to respect the watermarks are rare
high-priority events. Reorder the code such that per-zone dirty limits
and future checks important only to regular page allocations are ignored
in these extraordinary situations.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Paul Bolle <paul.bollee@gmail.com>
Tested-by: Zlatko Calusic <zcalusic@bitsync.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8c68ef1..9884aa0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1889,12 +1889,17 @@
*/
for_each_zone_zonelist_nodemask(zone, z, zonelist,
high_zoneidx, nodemask) {
+ unsigned long mark;
+
if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
!zlc_zone_worth_trying(zonelist, z, allowednodes))
continue;
if ((alloc_flags & ALLOC_CPUSET) &&
!cpuset_zone_allowed_softwall(zone, gfp_mask))
continue;
+ BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
+ if (alloc_flags & ALLOC_NO_WATERMARKS)
+ goto try_this_zone;
/*
* When allocating a page cache page for writing, we
* want to get it from a zone that is within its dirty
@@ -1925,16 +1930,11 @@
(gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone))
goto this_zone_full;
- BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
- if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
- unsigned long mark;
+ mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
+ if (!zone_watermark_ok(zone, order, mark,
+ classzone_idx, alloc_flags)) {
int ret;
- mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
- if (zone_watermark_ok(zone, order, mark,
- classzone_idx, alloc_flags))
- goto try_this_zone;
-
if (IS_ENABLED(CONFIG_NUMA) &&
!did_zlc_setup && nr_online_nodes > 1) {
/*