From 9bbc04eeb01fcb5c20bb10f34989665df7200163 Mon Sep 17 00:00:00 2001 From: Weijie Yang Date: Mon, 7 Apr 2014 15:37:00 -0700 Subject: [PATCH] mm/vmscan: do not check compaction_ready on promoted zones We abort direct reclaim if we find the zone is ready for compaction. Sometimes the zone is just a promoted highmem zone to force a scan of highmem, which is not the intended zone the caller want to allocate a page from. In this situation, setting aborted_reclaim to indicate the caller turned back to retry the allocation is waste of time and could cause a loop in __alloc_pages_slowpath(). This patch does not check compaction_ready() on promoted zones to avoid the above situation. Only set aborted_reclaim if the caller intended zone is ready for compaction. Signed-off-by: Weijie Yang Acked-by: Rik van Riel Acked-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 1c51e4f52fd9..06879ead7380 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2318,6 +2318,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) struct shrink_control shrink = { .gfp_mask = sc->gfp_mask, }; + enum zone_type requested_highidx = gfp_zone(sc->gfp_mask); /* * If the number of buffer_heads in the machine exceeds the maximum @@ -2358,7 +2359,8 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) * noticeable problem, like transparent huge * page allocations. */ - if (compaction_ready(zone, sc)) { + if ((zonelist_zone_idx(z) <= requested_highidx) + && compaction_ready(zone, sc)) { aborted_reclaim = true; continue; } -- 2.20.1