From: Christoph Hellwig <hch@infradead.org>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, nauman@google.com,
dpshah@google.com, guijianfeng@cn.fujitsu.com, jmoyer@redhat.com,
czoccolo@gmail.com
Subject: Re: [RFC PATCH] cfq-iosced: Implement IOPS mode and group_idle tunable V3
Date: Thu, 22 Jul 2010 01:56:02 -0400 [thread overview]
Message-ID: <20100722055602.GA18566@infradead.org> (raw)
In-Reply-To: <1279739181-24482-1-git-send-email-vgoyal@redhat.com>
On Wed, Jul 21, 2010 at 03:06:18PM -0400, Vivek Goyal wrote:
> On high end storage (I got on HP EVA storage array with 12 SATA disks in
> RAID 5),
That's actually quite low end storage for a server these days :)
> So this is not the default mode. This new tunable group_idle, allows one to
> set slice_idle=0 to disable some of the CFQ features and and use primarily
> group service differentation feature.
While this is better than before needing a sysfs tweak to get any
performance out of any kind of server class hardware still is pretty
horrible. And slice_idle=0 is not exactly the most obvious paramter
I would look for either. So having some way to automatically disable
this mode based on hardware characteristics would be really useful,
and if that's not possible at least make sure it's very obviously
document and easily found using web searches.
Btw, what effect does slice_idle=0 with your patches have to single SATA
disk and single SSD setups?
next prev parent reply other threads:[~2010-07-22 5:56 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-21 19:06 [RFC PATCH] cfq-iosced: Implement IOPS mode and group_idle tunable V3 Vivek Goyal
2010-07-21 19:06 ` [PATCH 1/3] cfq-iosched: Implment IOPS mode Vivek Goyal
2010-07-21 20:33 ` Jeff Moyer
2010-07-21 20:57 ` Vivek Goyal
2010-07-21 19:06 ` [PATCH 2/3] cfq-iosched: Implement a tunable group_idle Vivek Goyal
2010-07-21 19:40 ` Jeff Moyer
2010-07-21 20:13 ` Vivek Goyal
2010-07-21 20:54 ` Jeff Moyer
2010-07-21 19:06 ` [PATCH 3/3] cfq-iosched: Print number of sectors dispatched per cfqq slice Vivek Goyal
2010-07-22 5:56 ` Christoph Hellwig [this message]
2010-07-22 14:00 ` [RFC PATCH] cfq-iosced: Implement IOPS mode and group_idle tunable V3 Vivek Goyal
2010-07-24 8:51 ` Christoph Hellwig
2010-07-24 9:07 ` Corrado Zoccolo
2010-07-26 14:30 ` Vivek Goyal
2010-07-26 21:21 ` Tuning IO scheduler (Was: Re: [RFC PATCH] cfq-iosced: Implement IOPS mode and group_idle tunable V3) Vivek Goyal
2010-07-26 14:33 ` [RFC PATCH] cfq-iosced: Implement IOPS mode and group_idle tunable V3 Vivek Goyal
2010-07-29 19:57 ` Corrado Zoccolo
2010-07-26 13:51 ` Vivek Goyal
2010-07-22 20:54 ` Vivek Goyal
2010-07-22 7:08 ` Gui Jianfeng
2010-07-22 14:49 ` Vivek Goyal
2010-07-22 23:53 ` Gui Jianfeng
2010-07-26 6:58 ` Gui Jianfeng
2010-07-26 14:10 ` Vivek Goyal
2010-07-27 8:33 ` Gui Jianfeng
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