mm/compaction: more trace to understand when/why compaction start/finish

[cascardo/linux.git] / mm / compaction.c

diff --git a/mm/compaction.c b/mm/compaction.c
index b12df9f..b6ede45 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -41,6 +41,8 @@ static const char *const compaction_status_string[] = {
        "continue",
        "partial",
        "complete",
+       "no_suitable_page",
+       "not_suitable_zone",
 };
 #endif
 
@@ -1049,7 +1051,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
        return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE;
 }
 
-static int compact_finished(struct zone *zone, struct compact_control *cc,
+static int __compact_finished(struct zone *zone, struct compact_control *cc,
                            const int migratetype)
 {
        unsigned int order;
@@ -1104,7 +1106,20 @@ static int compact_finished(struct zone *zone, struct compact_control *cc,
                        return COMPACT_PARTIAL;
        }
 
-       return COMPACT_CONTINUE;
+       return COMPACT_NO_SUITABLE_PAGE;
+}
+
+static int compact_finished(struct zone *zone, struct compact_control *cc,
+                           const int migratetype)
+{
+       int ret;
+
+       ret = __compact_finished(zone, cc, migratetype);
+       trace_mm_compaction_finished(zone, cc->order, ret);
+       if (ret == COMPACT_NO_SUITABLE_PAGE)
+               ret = COMPACT_CONTINUE;
+
+       return ret;
 }
 
 /*
@@ -1114,7 +1129,7 @@ static int compact_finished(struct zone *zone, struct compact_control *cc,
  *   COMPACT_PARTIAL  - If the allocation would succeed without compaction
  *   COMPACT_CONTINUE - If compaction should run now
  */
-unsigned long compaction_suitable(struct zone *zone, int order,
+static unsigned long __compaction_suitable(struct zone *zone, int order,
                                        int alloc_flags, int classzone_idx)
 {
        int fragindex;
@@ -1158,11 +1173,24 @@ unsigned long compaction_suitable(struct zone *zone, int order,
         */
        fragindex = fragmentation_index(zone, order);
        if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)
-               return COMPACT_SKIPPED;
+               return COMPACT_NOT_SUITABLE_ZONE;
 
        return COMPACT_CONTINUE;
 }
 
+unsigned long compaction_suitable(struct zone *zone, int order,
+                                       int alloc_flags, int classzone_idx)
+{
+       unsigned long ret;
+
+       ret = __compaction_suitable(zone, order, alloc_flags, classzone_idx);
+       trace_mm_compaction_suitable(zone, order, ret);
+       if (ret == COMPACT_NOT_SUITABLE_ZONE)
+               ret = COMPACT_SKIPPED;
+
+       return ret;
+}
+
 static int compact_zone(struct zone *zone, struct compact_control *cc)
 {
        int ret;
@@ -1376,6 +1404,8 @@ unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
        if (!order || !may_enter_fs || !may_perform_io)
                return COMPACT_SKIPPED;
 
+       trace_mm_compaction_try_to_compact_pages(order, gfp_mask, mode);
+
        /* Compact each zone in the list */
        for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
                                                                ac->nodemask) {