From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
Subject: Re: [PATCH] mm/workingset: do not forget to unlock page
Date: Wed, 3 Feb 2016 17:02:53 -0500
Message-ID: <20160203220253.GA6859@cmpxchg.org>
References: <1454493513-19316-1-git-send-email-sergey.senozhatsky@gmail.com>
 <20160203104136.GA517@swordfish>
 <20160203162400.GB10440@cmpxchg.org>
 <20160203131939.1a35d9bc03f13b2b143d27c0@linux-foundation.org>
Mime-Version: 1.0
Return-path: <cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Content-Disposition: inline
In-Reply-To: <20160203131939.1a35d9bc03f13b2b143d27c0-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
List-ID: <cgroups.vger.kernel.org>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Vladimir Davydov <vdavydov-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>, Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sergey Senozhatsky <sergey.senozhatsky-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

On Wed, Feb 03, 2016 at 01:19:39PM -0800, Andrew Morton wrote:
> Yup.  I turned it into a fix against
> mm-workingset-per-cgroup-cache-thrash-detection.patch, which is where
> the bug was added.  And I did the goto thing instead, so the final
> result will be
> 
> void workingset_activation(struct page *page)
> {
> 	struct lruvec *lruvec;
> 
> 	lock_page_memcg(page);
> 	/*
> 	 * Filter non-memcg pages here, e.g. unmap can call
> 	 * mark_page_accessed() on VDSO pages.
> 	 *
> 	 * XXX: See workingset_refault() - this should return
> 	 * root_mem_cgroup even for !CONFIG_MEMCG.
> 	 */
> 	if (!mem_cgroup_disabled() && !page_memcg(page))
> 		goto out;
> 	lruvec = mem_cgroup_zone_lruvec(page_zone(page), page_memcg(page));
> 	atomic_long_inc(&lruvec->inactive_age);
> out:
> 	unlock_page_memcg(page);
> }

LGTM, thank you.