diff options
author | Sahitya Tummala <stummala@codeaurora.org> | 2017-07-10 15:49:57 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-21 07:44:56 +0200 |
commit | 2d0db02d2e8f45e215fd2e646820c669c6e70159 (patch) | |
tree | 48a7e42a0adb43d9ec72c45cf1b4e7a5f21ed06d /include | |
parent | 717ce69e47f0d77571b5a564784d16c1d920ee9b (diff) |
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 <stummala@codeaurora.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexander Polakov <apolyakov@beget.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/list_lru.h | 1 |
1 files changed, 1 insertions, 0 deletions
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 { |