From: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
To: Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>
Cc: Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Hugh Dickins <hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [patch] mm: memcontrol: avoid charge statistics churn during page migration
Date: Tue, 5 Aug 2014 09:12:23 -0400 [thread overview]
Message-ID: <20140805131223.GA14734@cmpxchg.org> (raw)
In-Reply-To: <20140805122434.GD15908-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
On Tue, Aug 05, 2014 at 02:24:34PM +0200, Michal Hocko wrote:
> On Mon 04-08-14 16:34:29, Johannes Weiner wrote:
> > Charge migration currently disables IRQs twice to update the charge
> > statistics for the old page and then again for the new page.
> >
> > But migration is a seemless transition of a charge from one physical
> > page to another one of the same size, so this should be a non-event
> > from an accounting point of view. Leave the statistics alone.
>
> Moving stats to mem_cgroup_commit_charge sounds logical to me but does
> this work properly even for the fuse replace page cache case when old
> and new pages can already live in different memcgs?
We don't migrate if the new page is already charged.
next prev parent reply other threads:[~2014-08-05 13:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-04 20:34 [patch] mm: memcontrol: avoid charge statistics churn during page migration Johannes Weiner
[not found] ` <1407184469-20741-1-git-send-email-hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
2014-08-05 12:24 ` Michal Hocko
[not found] ` <20140805122434.GD15908-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2014-08-05 13:12 ` Johannes Weiner [this message]
[not found] ` <20140805131223.GA14734-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
2014-08-05 13:34 ` Michal Hocko
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