We abort direct reclaim if find the zone is ready for compaction. Sometimes the zone is just a promoted highmem zone to force scan pinning highmem, which is not the intended zone the caller want to alloc page from. In this situation, setting aborted_reclaim to indicate the caller turn back to retry allocation is waste of time and could cause a loop in __alloc_pages_slowpath().
This patch do not check compaction_ready() on promoted zones to avoid the above situation, only set aborted_reclaim if the caller intended zone is ready to compaction. Signed-off-by: Weijie Yang <[email protected]> --- mm/vmscan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 35879f0..73e2577 100755 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2299,6 +2299,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) unsigned long nr_soft_scanned; bool aborted_reclaim = false; bool promoted_mask = false; + enum zone_type requested_highidx = gfp_zone(sc->gfp_mask); /* * If the number of buffer_heads in the machine exceeds the maximum @@ -2334,7 +2335,8 @@ 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; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
