mm: cma: skip watermarks check for already isolated blocks in split_free_page()
Since commit 2139cbe627b8 ("cma: fix counting of isolated pages") free
pages in isolated pageblocks are not accounted to NR_FREE_PAGES counters,
so watermarks check is not required if one operates on a free page in
isolated pageblock.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
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 d9fbac1..265fea4fb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1394,21 +1394,22 @@
zone = page_zone(page);
order = page_order(page);
+ mt = get_pageblock_migratetype(page);
- /* Obey watermarks as if the page was being allocated */
- watermark = low_wmark_pages(zone) + (1 << order);
- if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
- return 0;
+ if (mt != MIGRATE_ISOLATE) {
+ /* Obey watermarks as if the page was being allocated */
+ watermark = low_wmark_pages(zone) + (1 << order);
+ if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
+ return 0;
+
+ __mod_zone_freepage_state(zone, -(1UL << alloc_order), mt);
+ }
/* Remove page from free list */
list_del(&page->lru);
zone->free_area[order].nr_free--;
rmv_page_order(page);
- mt = get_pageblock_migratetype(page);
- if (unlikely(mt != MIGRATE_ISOLATE))
- __mod_zone_freepage_state(zone, -(1UL << alloc_order), mt);
-
if (alloc_order != order)
expand(zone, page, alloc_order, order,
&zone->free_area[order], migratetype);