Commit 9bbc04ee authored by Weijie Yang's avatar Weijie Yang Committed by Linus Torvalds

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: default avatarWeijie Yang <>
Acked-by: default avatarRik van Riel <>
Acked-by: default avatarMel Gorman <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 619d0d76
......@@ -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;
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