From: Jens Axboe <jens.axboe@oracle.com>
To: Corrado Zoccolo <czoccolo@gmail.com>
Cc: Linux-Kernel <linux-kernel@vger.kernel.org>,
Jeff Moyer <jmoyer@redhat.com>, Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH] cfq-iosched: reduce write depth only if sync was delayed
Date: Sun, 6 Dec 2009 11:49:50 +0100 [thread overview]
Message-ID: <20091206104950.GN8742@kernel.dk> (raw)
In-Reply-To: <4e5e476b0912060245x4d64300hb9689243bd712f2c@mail.gmail.com>
On Sun, Dec 06 2009, Corrado Zoccolo wrote:
> Hi Jeff,
> I remember you saw large performance drop on your SAN for sequential
> writes with low_latency=1. Can you test if Shaohua's and this patch
> fix allow to recover some bandwidth? I think that enabling the queue
> depth ramp up only if a sync request was delayed should disable it for
> fast hardware like yours, so you should not be seeing the slowdown any
> more.
I queued this up for post inclusion into 2.6.33, with the time_after()
fixed.
The patch was word-wrapped, btw.
--
Jens Axboe
next prev parent reply other threads:[~2009-12-06 10:49 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-04 12:35 [PATCH] cfq-iosched: reduce write depth only if sync was delayed Corrado Zoccolo
2009-12-05 11:13 ` Corrado Zoccolo
2009-12-06 10:45 ` Corrado Zoccolo
2009-12-06 10:49 ` Jens Axboe [this message]
2009-12-07 14:13 ` Jeff Moyer
2009-12-07 14:41 ` Jens Axboe
2009-12-07 16:45 ` Jeff Moyer
2009-12-07 17:04 ` Vivek Goyal
2009-12-07 17:27 ` Vivek Goyal
2009-12-07 18:03 ` Vivek Goyal
2009-12-08 0:07 ` Jeff Moyer
2009-12-08 20:43 ` Corrado Zoccolo
2009-12-09 18:09 ` Jeff Moyer
2009-12-11 17:15 ` Corrado Zoccolo
2009-12-11 17:50 ` Jeff Moyer
2009-12-18 15:32 ` Jeff Moyer
2009-12-18 21:03 ` Corrado Zoccolo
2009-12-08 18:00 ` Jeff Moyer
2009-12-08 20:46 ` Corrado Zoccolo
2009-12-09 18:16 ` Jeff Moyer
2009-12-09 19:05 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2009-12-09 19:45 Corrado Zoccolo
2009-12-09 19:51 ` Jeff Moyer
2009-12-09 19:54 ` Jens Axboe
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