From: Richard Davies <richard.davies@elastichosts.com>
To: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Satoru Moriya <satoru.moriya@hds.com>,
Jerome Marchand <jmarchan@redhat.com>,
"jweiner@redhat.com" <jweiner@redhat.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"lwoodman@redhat.com" <lwoodman@redhat.com>,
"shaohua.li@intel.com" <shaohua.li@intel.com>,
"dle-develop@lists.sourceforge.net"
<dle-develop@lists.sourceforge.net>,
Seiji Aguchi <seiji.aguchi@hds.com>,
Minchan Kim <minchan.kim@gmail.com>
Subject: Re: [RFC][PATCH] avoid swapping out with swappiness==0
Date: Mon, 21 May 2012 08:12:26 +0100 [thread overview]
Message-ID: <20120521071226.GJ29495@alpha.arachsys.com> (raw)
In-Reply-To: <4FA82C11.2030805@redhat.com>
Hi Satoru,
Rik van Riel wrote:
> KOSAKI Motohiro wrote:
> > Richard Davies wrote:
> > >Satoru Moriya wrote:
> > > > > I have run into problems with heavy swapping with swappiness==0 and
> > > > > was pointed to this thread (
> > > > > http://marc.info/?l=linux-mm&m=133522782307215 )
> > > >
> > > > Did you test this patch with your workload?
> > >
> > > I haven't yet tested this patch. It takes a long time since these are
> > > production machines, and the bug itself takes several weeks of
> > > production use to really show up.
> > >
> > > Rik van Riel has pointed out a lot of VM tweaks that he put into 3.4:
> > > http://marc.info/?l=linux-mm&m=133536506926326
> > >
> > > My intention is to reboot half of our machines into plain 3.4 once it
> > > is out, and half onto 3.4 + your patch.
> > >
> > > Then we can compare behaviour.
> > >
> > > Will your patch apply cleanly on 3.4?
> >
> > Note. This patch doesn't solve your issue. This patch mean,
> > when occuring very few swap io, it change to 0. But you said
> > you are seeing eager swap io. As Dave already pointed out, your
> > machine have buffer head issue.
> >
> > So, this thread is pointless.
>
> Running KVM guests directly off block devices results in a lot
> of buffer cache.
>
> I suspect that this patch will in fact fix Richard's issue.
>
> The patch is small, fairly simple and looks like it will fix
> people's problems. It also makes swappiness=0 behave the way
> most people seem to imagine it would work.
>
> If it works for a few people (test results), I believe we
> might as well merge it.
>
> Yes, for cgroups we may need additional logic, but we can
> sort that out as we go along.
Now that 3.4 is out with Rik's fixes, I'm keen to start testing with and
without this extra patch.
Satoru - should I just apply your original patch (most likely), or do you
need to update for the final released kernel?
Thanks,
Richard.
next prev parent reply other threads:[~2012-05-21 7:12 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-02 17:36 [RFC][PATCH] avoid swapping out with swappiness==0 Satoru Moriya
2012-03-02 22:47 ` Rik van Riel
2012-03-02 23:43 ` Satoru Moriya
2012-03-03 2:29 ` Hillf Danton
2012-03-04 6:57 ` Minchan Kim
2012-03-05 21:38 ` Satoru Moriya
2012-03-05 13:49 ` Rik van Riel
2012-03-05 21:56 ` Johannes Weiner
2012-03-07 17:19 ` KOSAKI Motohiro
2012-03-07 18:18 ` Satoru Moriya
2012-03-30 22:44 ` Satoru Moriya
2012-04-02 17:10 ` KOSAKI Motohiro
2012-04-03 11:25 ` Jerome Marchand
2012-04-03 15:15 ` Satoru Moriya
2012-04-04 17:38 ` KOSAKI Motohiro
2012-04-21 0:21 ` Satoru Moriya
2012-05-11 21:11 ` Satoru Moriya
2012-05-12 22:21 ` Rik van Riel
2012-04-24 8:20 ` Richard Davies
2012-04-24 22:14 ` Satoru Moriya
2012-04-26 14:26 ` Richard Davies
2012-04-26 15:41 ` KOSAKI Motohiro
2012-05-07 20:09 ` Rik van Riel
2012-05-08 0:05 ` Minchan Kim
2012-05-21 7:12 ` Richard Davies [this message]
2012-05-21 13:39 ` Satoru Moriya
2012-04-26 14:50 ` Christoph Lameter
2012-04-26 15:37 ` KOSAKI Motohiro
2012-04-26 16:08 ` Richard Davies
2012-04-26 18:20 ` Christoph Lameter
2012-04-27 13:55 ` Rik van Riel
2012-05-07 20:11 ` Rik van Riel
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