The patch titled
Subject: mm/memcg: fix incorrect flushing of lruvec data in obj_stock
has been added to the -mm tree. Its filename is
mm-memcg-fix-incorrect-flushing-of-lruvec-data-in-obj_stock.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-fix-incorrect-flushing-of-lruvec-data-in-obj_stock.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-fix-incorrect-flushing-of-lruvec-data-in-obj_stock.patch
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From: Waiman Long <longman@xxxxxxxxxx>
Subject: mm/memcg: fix incorrect flushing of lruvec data in obj_stock
When mod_objcg_state() is called with a pgdat that is different from that
in the obj_stock, the old lruvec data cached in obj_stock are flushed out.
Unfortunately, they were flushed to the new pgdat and so the data go to
the wrong node. This will screw up the slab data reported in
/sys/devices/system/node/node*/meminfo.
Fix that by flushing the data to the cached pgdat instead.
Link: https://lkml.kernel.org/r/20210802143834.30578-1-longman@xxxxxxxxxx
Fixes: 68ac5b3c8db2 ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp")
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Chris Down <chris@xxxxxxxxxxxxxx>
Cc: Yafang Shao <laoar.shao@xxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Masayoshi Mizuma <msys.mizuma@xxxxxxxxx>
Cc: Xing Zhengjun <zhengjun.xing@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Waiman Long <longman@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/memcontrol.c~mm-memcg-fix-incorrect-flushing-of-lruvec-data-in-obj_stock
+++ a/mm/memcontrol.c
@@ -3106,13 +3106,15 @@ void mod_objcg_state(struct obj_cgroup *
stock->cached_pgdat = pgdat;
} else if (stock->cached_pgdat != pgdat) {
/* Flush the existing cached vmstat data */
+ struct pglist_data *oldpg = stock->cached_pgdat;
+
if (stock->nr_slab_reclaimable_b) {
- mod_objcg_mlstate(objcg, pgdat, NR_SLAB_RECLAIMABLE_B,
+ mod_objcg_mlstate(objcg, oldpg, NR_SLAB_RECLAIMABLE_B,
stock->nr_slab_reclaimable_b);
stock->nr_slab_reclaimable_b = 0;
}
if (stock->nr_slab_unreclaimable_b) {
- mod_objcg_mlstate(objcg, pgdat, NR_SLAB_UNRECLAIMABLE_B,
+ mod_objcg_mlstate(objcg, oldpg, NR_SLAB_UNRECLAIMABLE_B,
stock->nr_slab_unreclaimable_b);
stock->nr_slab_unreclaimable_b = 0;
}
_
Patches currently in -mm which might be from longman@xxxxxxxxxx are
mm-memcg-fix-incorrect-flushing-of-lruvec-data-in-obj_stock.patch
