提交 46dafbca 编写于 作者: M Mel Gorman 提交者: Linus Torvalds

Be more agressive about stealing when MIGRATE_RECLAIMABLE allocations fallback

MIGRATE_RECLAIMABLE allocations tend to be very bursty in nature like when
updatedb starts.  It is likely this will occur in situations where MAX_ORDER
blocks of pages are not free.  This means that updatedb can scatter
MIGRATE_RECLAIMABLE pages throughout the address space.  This patch is more
agressive about stealing blocks of pages for MIGRATE_RECLAIMABLE.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 5adc5be7
......@@ -821,11 +821,23 @@ static struct page *__rmqueue_fallback(struct zone *zone, int order,
/*
* If breaking a large block of pages, move all free
* pages to the preferred allocation list
*/
if (unlikely(current_order >= MAX_ORDER / 2)) {
* pages to the preferred allocation list. If falling
* back for a reclaimable kernel allocation, be more
* agressive about taking ownership of free pages
*/
if (unlikely(current_order >= MAX_ORDER / 2) ||
start_migratetype == MIGRATE_RECLAIMABLE) {
unsigned long pages;
pages = move_freepages_block(zone, page,
start_migratetype);
/* Claim the whole block if over half of it is free */
if ((pages << current_order) >= (1 << (MAX_ORDER-2)) &&
migratetype != MIGRATE_HIGHATOMIC)
set_pageblock_migratetype(page,
start_migratetype);
migratetype = start_migratetype;
move_freepages_block(zone, page, migratetype);
}
/* Remove the page from the freelists */
......
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