From: Yafang Shao <laoar.shao@xxxxxxxxx>
Subject: mm/compaction.c: clear total_{migrate,free}_scanned before scanning a new zone
total_{migrate,free}_scanned will be added to COMPACTMIGRATE_SCANNED and
COMPACTFREE_SCANNED in compact_zone(). We should clear them before
scanning a new zone. In the proc triggered compaction, we forgot clearing
them.
[laoar.shao@xxxxxxxxx: introduce a helper compact_zone_counters_init()]
Link: http://lkml.kernel.org/r/1563869295-25748-1-git-send-email-laoar.shao@xxxxxxxxx
[akpm@xxxxxxxxxxxxxxxxxxxx: expand compact_zone_counters_init() into its single callsite, per mhocko]
[vbabka@xxxxxxx: squash compact_zone() list_head init as well]
Link: http://lkml.kernel.org/r/1fb6f7da-f776-9e42-22f8-bbb79b030b98@xxxxxxx
[akpm@xxxxxxxxxxxxxxxxxxxx: kcompactd_do_work(): avoid unnecessary initialization of cc.zone]
Link: http://lkml.kernel.org/r/1563789275-9639-1-git-send-email-laoar.shao@xxxxxxxxx
Fixes: 7f354a548d1c ("mm, compaction: add vmstats for kcompactd work")
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Yafang Shao <shaoyafang@xxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 35 +++++++++++++----------------------
1 file changed, 13 insertions(+), 22 deletions(-)
--- a/mm/compaction.c~mm-compaction-clear-total_migratefree_scanned-before-scanning-a-new-zone
+++ a/mm/compaction.c
@@ -2078,6 +2078,17 @@ compact_zone(struct compact_control *cc,
const bool sync = cc->mode != MIGRATE_ASYNC;
bool update_cached;
+ /*
+ * These counters track activities during zone compaction. Initialize
+ * them before compacting a new zone.
+ */
+ cc->total_migrate_scanned = 0;
+ cc->total_free_scanned = 0;
+ cc->nr_migratepages = 0;
+ cc->nr_freepages = 0;
+ INIT_LIST_HEAD(&cc->freepages);
+ INIT_LIST_HEAD(&cc->migratepages);
+
cc->migratetype = gfpflags_to_migratetype(cc->gfp_mask);
ret = compaction_suitable(cc->zone, cc->order, cc->alloc_flags,
cc->classzone_idx);
@@ -2281,10 +2292,6 @@ static enum compact_result compact_zone_
{
enum compact_result ret;
struct compact_control cc = {
- .nr_freepages = 0,
- .nr_migratepages = 0,
- .total_migrate_scanned = 0,
- .total_free_scanned = 0,
.order = order,
.search_order = order,
.gfp_mask = gfp_mask,
@@ -2305,8 +2312,6 @@ static enum compact_result compact_zone_
if (capture)
current->capture_control = &capc;
- INIT_LIST_HEAD(&cc.freepages);
- INIT_LIST_HEAD(&cc.migratepages);
ret = compact_zone(&cc, &capc);
@@ -2408,8 +2413,6 @@ static void compact_node(int nid)
struct zone *zone;
struct compact_control cc = {
.order = -1,
- .total_migrate_scanned = 0,
- .total_free_scanned = 0,
.mode = MIGRATE_SYNC,
.ignore_skip_hint = true,
.whole_zone = true,
@@ -2423,11 +2426,7 @@ static void compact_node(int nid)
if (!populated_zone(zone))
continue;
- cc.nr_freepages = 0;
- cc.nr_migratepages = 0;
cc.zone = zone;
- INIT_LIST_HEAD(&cc.freepages);
- INIT_LIST_HEAD(&cc.migratepages);
compact_zone(&cc, NULL);
@@ -2529,8 +2528,6 @@ static void kcompactd_do_work(pg_data_t
struct compact_control cc = {
.order = pgdat->kcompactd_max_order,
.search_order = pgdat->kcompactd_max_order,
- .total_migrate_scanned = 0,
- .total_free_scanned = 0,
.classzone_idx = pgdat->kcompactd_classzone_idx,
.mode = MIGRATE_SYNC_LIGHT,
.ignore_skip_hint = false,
@@ -2554,16 +2551,10 @@ static void kcompactd_do_work(pg_data_t
COMPACT_CONTINUE)
continue;
- cc.nr_freepages = 0;
- cc.nr_migratepages = 0;
- cc.total_migrate_scanned = 0;
- cc.total_free_scanned = 0;
- cc.zone = zone;
- INIT_LIST_HEAD(&cc.freepages);
- INIT_LIST_HEAD(&cc.migratepages);
-
if (kthread_should_stop())
return;
+
+ cc.zone = zone;
status = compact_zone(&cc, NULL);
if (status == COMPACT_SUCCESS) {
_
