From: Jan Kara <jack@suse.cz>
To: Chad Talbott <ctalbott@google.com>
Cc: Vivek Goyal <vgoyal@redhat.com>,
lsf-pc@lists.linuxfoundation.org, linux-fsdevel@vger.kernel.org
Subject: Re: [LSF/FS TOPIC] I/O performance isolation for shared storage
Date: Tue, 15 Feb 2011 13:54:42 +0100 [thread overview]
Message-ID: <20110215125442.GE17313@quack.suse.cz> (raw)
In-Reply-To: <AANLkTikb=FZ3im0Rngf=+XfdTU7nb+Vzjx1mJ2gVCoB1@mail.gmail.com>
On Fri 04-02-11 15:07:15, Chad Talbott wrote:
> > Also curious to know if per memory cgroup dirty ration stuff got in and how
> > did we deal with the issue of selecting which inode to dispatch the writes
> > from based on the cgroup it belongs to.
>
> We have some experience with per-cgroup writeback under our fake-NUMA
> memory container system. Writeback under memcg will likely face
> similar issues. See Greg Thelen's topic description at
> http://article.gmane.org/gmane.linux.kernel.mm/58164 for a request for
> discussion.
>
> Per-cgroup dirty ratios is just the beginning, as you mention. Unless
> the IO scheduler can see the deep queues of all the blocked tasks, it
> can't make the right decisions. Also, today writeback is ignorant of
> the tasks' debt to the IO scheduler, so it issues the "wrong" inodes.
I'm curious: Could you elaborate a bit more about this? I'm not sure what
a debt to the IO scheduler is and why choice of inodes would matter...
Thanks.
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2011-02-15 12:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-04 1:50 [LSF/FS TOPIC] I/O performance isolation for shared storage Chad Talbott
2011-02-04 2:31 ` Vivek Goyal
2011-02-04 23:07 ` Chad Talbott
2011-02-07 18:06 ` Vivek Goyal
2011-02-07 19:40 ` Chad Talbott
2011-02-07 20:38 ` Vivek Goyal
2011-02-15 12:54 ` Jan Kara [this message]
2011-02-15 23:15 ` Chad Talbott
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