mm-compaction-add-the-ultimate-direct-compaction-priority-fix

Use the MIN_COMPACT_PRIORITY alias instead of COMPACT_PRIO_SYNC_FULL to
disable heuristics "because this would be easier to follow and it would be
easier for future changes", per Michal.

Link: http://lkml.kernel.org/r/d443b884-87e7-1c93-8684-3a3a35759fb1@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/compaction.c b/mm/compaction.c
index 342fa9e3127a4ee1733e73bcf3c1062e71643610..21040304f4d20238a0c2595a9f6b470cb3dbc7ed 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1644,8 +1644,8 @@ static enum compact_result compact_zone_order(struct zone *zone, int order,
                .alloc_flags = alloc_flags,
                .classzone_idx = classzone_idx,
                .direct_compaction = true,
-               .whole_zone = (prio == COMPACT_PRIO_SYNC_FULL),
-               .ignore_skip_hint = (prio == COMPACT_PRIO_SYNC_FULL)
+               .whole_zone = (prio == MIN_COMPACT_PRIORITY),
+               .ignore_skip_hint = (prio == MIN_COMPACT_PRIORITY)
        };
        INIT_LIST_HEAD(&cc.freepages);
        INIT_LIST_HEAD(&cc.migratepages);
@@ -1691,7 +1691,7 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
                                                                ac->nodemask) {
                enum compact_result status;
 
-               if (prio > COMPACT_PRIO_SYNC_FULL
+               if (prio > MIN_COMPACT_PRIORITY
                                        && compaction_deferred(zone, order)) {
                        rc = max_t(enum compact_result, COMPACT_DEFERRED, rc);
                        continue;