From: Jeff Moyer <jmoyer@redhat.com>
To: Corrado Zoccolo <czoccolo@gmail.com>
Cc: Jan Kara <jack@suse.cz>,
jens.axboe@oracle.com, LKML <linux-kernel@vger.kernel.org>,
Chris Mason <chris.mason@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Galbraith <efault@gmx.de>
Subject: Re: Performance regression in IO scheduler still there
Date: Fri, 06 Nov 2009 09:14:53 -0500 [thread overview]
Message-ID: <x494op7ivtu.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <4e5e476b0911051500j7587dd6dh975148475418efcf@mail.gmail.com> (Corrado Zoccolo's message of "Fri, 6 Nov 2009 00:00:40 +0100")
Corrado Zoccolo <czoccolo@gmail.com> writes:
> Hi Jeff,
> what hardware are you using for tests?
> I see aggregated random read bandwidth is larger than sequential read
> bandwidth, and write bandwidth greater than read.
> Is this a SAN with multiple independent spindles?
Yeah, this is a single path to an HP EVA storage array. There are 24 or
so disks striped in the pool used to create the volume I am using. Jan,
could you repeat your tests with /sys/block/sdX/queue/iosched/low_latency
set to 0?
Cheers,
Jeff
next prev parent reply other threads:[~2009-11-06 14:15 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-26 17:20 Performance regression in IO scheduler still there Jan Kara
2009-10-26 17:26 ` Jeff Moyer
2009-11-05 20:10 ` Jeff Moyer
2009-11-05 23:00 ` Corrado Zoccolo
2009-11-06 14:14 ` Jeff Moyer [this message]
2009-11-10 18:37 ` Jan Kara
2009-11-06 18:56 ` Jeff Moyer
2009-11-08 17:01 ` Corrado Zoccolo
2009-11-10 16:47 ` Jeff Moyer
2009-11-10 17:37 ` Corrado Zoccolo
2009-11-11 14:10 ` Jan Kara
2009-11-11 17:43 ` Jeff Moyer
2009-11-12 17:29 ` Jan Kara
2009-11-12 20:44 ` Jeff Moyer
2009-11-12 21:00 ` Jens Axboe
2009-11-12 21:05 ` Jeff Moyer
2009-11-13 7:45 ` Jens Axboe
2009-11-16 10:47 ` Jan Kara
2009-11-16 16:58 ` Jan Kara
2009-11-16 17:03 ` Jeff Moyer
2009-11-16 18:38 ` Corrado Zoccolo
2009-11-16 22:17 ` Jan Kara
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