From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamezawa Hiroyuki Subject: Re: [patch 11/11] mm: memcg: only check anon swapin page charges for swap cache Date: Mon, 09 Jul 2012 12:44:30 +0900 Message-ID: <4FFA539E.70805@jp.fujitsu.com> References: <1341449103-1986-1-git-send-email-hannes@cmpxchg.org> <1341449103-1986-12-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1341449103-1986-12-git-send-email-hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , Hugh Dickins , David Rientjes , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org (2012/07/05 9:45), Johannes Weiner wrote: > shmem knows for sure that the page is in swap cache when attempting to > charge a page, because the cache charge entry function has a check for > it. Only anon pages may be removed from swap cache already when > trying to charge their swapin. > > Adjust the comment, though: '4969c11 mm: fix swapin race condition' > added a stable PageSwapCache check under the page lock in the > do_swap_page() before calling the memory controller, so it's > unuse_pte()'s pte_same() that may fail. > > Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki