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From: Jan Kara <jack@suse.cz>
To: jens.axboe@oracle.com
Cc: LKML <linux-kernel@vger.kernel.org>,
	Jeff Moyer <jmoyer@redhat.com>,
	Chris Mason <chris.mason@oracle.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mike Galbraith <efault@gmx.de>
Subject: Performance regression in IO scheduler still there
Date: Mon, 26 Oct 2009 18:20:12 +0100	[thread overview]
Message-ID: <20091026172012.GC7233@duck.suse.cz> (raw)

  Hi,

  I took time and remeasured tiobench results on recent kernel. A short
conclusion is that there is still a performance regression which I reported
few months ago. The machine is Intel 2 CPU with 2 GB RAM and plain SATA
drive. tiobench sequential write performance numbers with 16 threads:
2.6.29:              AVG       STDERR
37.80 38.54 39.48 -> 38.606667 0.687475

2.6.32-rc5:
37.36 36.41 36.61 -> 36.793333 0.408928 

So about 5% regression. The regression happened sometime between 2.6.29 and
2.6.30 and stays the same since then... With deadline scheduler, there's
no regression. Shouldn't we do something about it?

								Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR

             reply	other threads:[~2009-10-26 17:20 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-26 17:20 Jan Kara [this message]
2009-10-26 17:26 ` Performance regression in IO scheduler still there Jeff Moyer
2009-11-05 20:10 ` Jeff Moyer
2009-11-05 23:00   ` Corrado Zoccolo
2009-11-06 14:14     ` Jeff Moyer
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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