From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: [PATCH] mm/memcg: Fix incorrect flushing of lruvec data in obj_stock Date: Sun, 1 Aug 2021 22:28:27 -0400 Message-ID: <20210802022827.10192-1-longman@redhat.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627871336; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=We5uPnQeByis91o/AyYOCOo9vmw3X7xwMVyvzEdXeeY=; b=YUiZKimBiV9cFsQUeSGSLbLIFvAL4m8W9NK/p8jvZnznyInzzVA+j6QxSuHivUkgtY3qlj S5dKBSkGJyH6OiCMWAnkZ+jWAZsukcjBFOvpip57RVzQML9jXljw+e5ix3xJNcQLUMsRv3 XmBmQs19ITpbRriCkzWEW3lFDnqG3UI= List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Tejun Heo , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Shakeel Butt , Muchun Song , Alex Shi , Chris Down , Yafang Shao , Wei Yang , Masayoshi Mizuma , Xing Zhengjun , Matthew Wilcox , Waiman Long 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 hence the wrong node, not the one cached in obj_stock. Fix that by flushing the data to the cached pgdat instead. Fixes: 68ac5b3c8db2 ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp") Signed-off-by: Waiman Long --- mm/memcontrol.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ae1f5d0cb581..881ec4ddddcd 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3106,17 +3106,19 @@ void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, stock->cached_pgdat = pgdat; } else if (stock->cached_pgdat != pgdat) { /* Flush the existing cached vmstat data */ + struct pglist_data *oldpg = stock->cached_pgdat; + + stock->cached_pgdat = 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; } - stock->cached_pgdat = pgdat; } bytes = (idx == NR_SLAB_RECLAIMABLE_B) ? &stock->nr_slab_reclaimable_b -- 2.18.1