From 2d0db02d2e8f45e215fd2e646820c669c6e70159 Mon Sep 17 00:00:00 2001 From: Sahitya Tummala Date: Mon, 10 Jul 2017 15:49:57 -0700 Subject: mm/list_lru.c: fix list_lru_count_node() to be race free commit 2c80cd57c74339889a8752b20862a16c28929c3a upstream. list_lru_count_node() iterates over all memcgs to get the total number of entries on the node but it can race with memcg_drain_all_list_lrus(), which migrates the entries from a dead cgroup to another. This can return incorrect number of entries from list_lru_count_node(). Fix this by keeping track of entries per node and simply return it in list_lru_count_node(). Link: http://lkml.kernel.org/r/1498707555-30525-1-git-send-email-stummala@codeaurora.org Signed-off-by: Sahitya Tummala Acked-by: Vladimir Davydov Cc: Jan Kara Cc: Alexander Polakov Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/list_lru.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h index 2a6b9947aaa3..743b34f56f2b 100644 --- a/include/linux/list_lru.h +++ b/include/linux/list_lru.h @@ -44,6 +44,7 @@ struct list_lru_node { /* for cgroup aware lrus points to per cgroup lists, otherwise NULL */ struct list_lru_memcg *memcg_lrus; #endif + long nr_items; } ____cacheline_aligned_in_smp; struct list_lru { -- cgit v1.2.3