From: Yafang Shao <laoar.shao@xxxxxxxxx> commit a94b525241c0fff3598809131d7cfcfe1d572d8c upstream. 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> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/compaction.c | 35 +++++++++++++---------------------- 1 file changed, 13 insertions(+), 22 deletions(-) --- a/mm/compaction.c +++ b/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) {