From: Jeff Moyer <jmoyer@redhat.com>
To: Vivek Goyal <vgoyal@redhat.com>, Corrado Zoccolo <czoccolo@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>,
Linux-Kernel <linux-kernel@vger.kernel.org>,
Shaohua Li <shaohua.li@intel.com>,
Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Subject: Re: [PATCH] cfq-iosched: non-rot devices do not need read queue merging
Date: Tue, 05 Jan 2010 16:19:08 -0500 [thread overview]
Message-ID: <x49y6kc6yib.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <20100105151353.GA4631@redhat.com> (Vivek Goyal's message of "Tue, 5 Jan 2010 10:13:53 -0500")
Vivek Goyal <vgoyal@redhat.com> writes:
> Thanks Jeff, one thing comes to mind. Now with recent changes, we drive deeper
> depths on SSD with NCQ and there are not many pending cfqq on service tree
> until and unless number of parallel threads exceed NCQ depth (32). If
> that's the case, then I think we might not be seeing lot of queue merging
> happening in this test case until and unless dump utility is creating more
> than 32 threads.
>
> If time permits, it might also be interesting to run the same test with queue
> depth 1 and see if SSDs without NCQ will suffer or not.
Corrado, I think what Vivek is getting at is that you should check for
both blk_queue_nonrot and cfqd->hw_tag (like in cfq_arm_slice_timer).
Do you agree?
Cheers,
Jeff
next prev parent reply other threads:[~2010-01-05 21:19 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-30 12:10 [PATCH] cfq-iosched: non-rot devices do not need " Corrado Zoccolo
2009-12-30 18:45 ` Jens Axboe
2009-12-30 20:31 ` Corrado Zoccolo
2009-12-30 21:11 ` Jens Axboe
2009-12-30 21:21 ` Corrado Zoccolo
2009-12-30 21:34 ` Jens Axboe
2009-12-30 22:22 ` [PATCH] cfq-iosched: non-rot devices do not need read " Corrado Zoccolo
2010-01-04 14:47 ` Vivek Goyal
2010-01-04 16:36 ` Corrado Zoccolo
2010-01-04 16:51 ` Jeff Moyer
2010-01-04 18:32 ` Vivek Goyal
2010-01-04 18:37 ` Corrado Zoccolo
2010-01-04 18:51 ` Vivek Goyal
2010-01-04 19:04 ` Jeff Moyer
2010-01-04 20:37 ` Corrado Zoccolo
2010-01-05 14:58 ` Jeff Moyer
2010-01-05 15:13 ` Vivek Goyal
2010-01-05 21:19 ` Jeff Moyer [this message]
2010-01-05 21:48 ` Corrado Zoccolo
2010-01-07 10:56 ` Kirill Afonshin
2010-01-07 13:38 ` Corrado Zoccolo
2010-01-07 14:36 ` Vivek Goyal
2010-01-07 17:00 ` Corrado Zoccolo
2010-01-07 18:37 ` Vivek Goyal
2010-01-07 20:16 ` Corrado Zoccolo
2010-01-08 18:53 ` Vivek Goyal
2010-01-10 12:55 ` Corrado Zoccolo
2010-01-10 21:04 ` [PATCH] cfq-iosched: NCQ SSDs " Corrado Zoccolo
2010-01-10 21:08 ` Corrado Zoccolo
2010-01-11 11:25 ` Jeff Garzik
2010-01-11 12:26 ` Corrado Zoccolo
2010-01-11 13:13 ` Jens Axboe
2010-01-11 13:18 ` Jeff Garzik
2010-01-11 13:24 ` Jens Axboe
2010-01-11 14:53 ` Corrado Zoccolo
2010-01-11 16:44 ` Vivek Goyal
2010-01-11 17:00 ` Corrado Zoccolo
2010-01-11 17:07 ` Vivek Goyal
2010-01-11 19:05 ` Corrado Zoccolo
2010-01-11 17:11 ` Vivek Goyal
2010-01-11 19:09 ` Corrado Zoccolo
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