From 2583d6713267a4c80126e4e50dd45f5cf685ebe8 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Fri, 17 Nov 2017 15:26:38 -0800 Subject: mm, compaction: split off flag for not updating skip hints Pageblock skip hints were added as a heuristic for compaction, which shares core code with CMA. Since CMA reliability would suffer from the heuristics, compact_control flag ignore_skip_hint was added for the CMA use case. Since 6815bf3f233e ("mm/compaction: respect ignore_skip_hint in update_pageblock_skip") the flag also means that CMA won't *update* the skip hints in addition to ignoring them. Today, direct compaction can also ignore the skip hints in the last resort attempt, but there's no reason not to set them when isolation fails in such case. Thus, this patch splits off a new no_set_skip_hint flag to avoid the updating, which only CMA sets. This should improve the heuristics a bit, and allow us to simplify the persistent skip bit handling as the next step. Link: http://lkml.kernel.org/r/20171102121706.21504-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka Acked-by: Mel Gorman Cc: David Rientjes Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 55ded92f9809..d4096f4a5c1f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7619,6 +7619,7 @@ int alloc_contig_range(unsigned long start, unsigned long end, .zone = page_zone(pfn_to_page(start)), .mode = MIGRATE_SYNC, .ignore_skip_hint = true, + .no_set_skip_hint = true, .gfp_mask = current_gfp_context(gfp_mask), }; INIT_LIST_HEAD(&cc.migratepages); -- cgit v1.2.3