From: Jan Kara <jack@suse.cz>
To: "tj@kernel.org" <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>, "jack@suse.cz" <jack@suse.cz>,
"vgoyal@redhat.com" <vgoyal@redhat.com>,
"lizefan@huawei.com" <lizefan@huawei.com>,
"gnehzuil.liu@gmail.com" <gnehzuil.liu@gmail.com>,
"tm@tao.ma" <tm@tao.ma>,
"lsf-pc@lists.linux-foundation.org"
<lsf-pc@lists.linux-foundation.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [Lsf-pc] [LSF/MM ATTEND] Filesystems -- Btrfs, cgroups, Storage topics from Facebook
Date: Fri, 3 Jan 2014 07:03:46 +0100 [thread overview]
Message-ID: <20140103060346.GA31086@quack.suse.cz> (raw)
In-Reply-To: <20140102161406.GI11501@htj.dyndns.org>
On Thu 02-01-14 11:14:06, tj@kernel.org wrote:
> Hey, again.
>
> On Thu, Jan 02, 2014 at 11:01:02AM -0500, tj@kernel.org wrote:
> > What we're missing is a way to make such split visible in the upper
> > layers for writeback. It seems rather clear to me that that's the
> > right way to approach the problem rather than implementing separate
> > control for writebacks and somehow coordinate that with the rest.
>
> To clarify a bit. I think what we need to do is splitting bdi's for
> each active blkcg (at least the part which is relevant to propagating
> io pressure upwards).
Well, the pressure is currently propagated by the fact that we block on
request allocation while writing back stuff... So this would mean splitting
bdi flusher workqueue per blkcg.
> I really don't think a scheme where we try to somehow split bandwidth
> number between two separate enforcing mechanisms is something we should
> go after.
Agreed.
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2014-01-03 6:03 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-30 21:36 [LSF/MM ATTEND] Filesystems -- Btrfs, cgroups, Storage topics from Facebook Chris Mason
2013-12-31 8:49 ` Zheng Liu
2013-12-31 9:36 ` Jeff Liu
2013-12-31 12:45 ` [Lsf-pc] " Jan Kara
2013-12-31 13:19 ` Chris Mason
2013-12-31 14:22 ` Tao Ma
2013-12-31 15:34 ` Chris Mason
2014-01-02 6:46 ` Jan Kara
2014-01-02 15:21 ` Chris Mason
2014-01-02 16:01 ` tj
2014-01-02 16:14 ` tj
2014-01-03 6:03 ` Jan Kara [this message]
2014-01-02 17:06 ` Vivek Goyal
2014-01-02 17:10 ` tj
2014-01-02 19:11 ` Chris Mason
2014-01-03 6:39 ` Jan Kara
2014-01-02 18:27 ` James Bottomley
2014-01-02 18:36 ` tj
2014-01-03 7:44 ` James Bottomley
2014-01-08 15:04 ` Mel Gorman
2014-01-08 16:14 ` Chris Mason
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