From: Jens Axboe <axboe@suse.de>
To: Vishal Patil <vishpat@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Jan Engelhardt <jengelh@linux01.gwdg.de>
Subject: Re: CSCAN vs CFQ I/O scheduler benchmark results
Date: Mon, 12 Jun 2006 08:41:36 +0200 [thread overview]
Message-ID: <20060612064136.GB4420@suse.de> (raw)
In-Reply-To: <4745278c0606111647g7ca1392bjb46936f69d6b668d@mail.gmail.com>
(please don't top post)
On Sun, Jun 11 2006, Vishal Patil wrote:
> Jan
>
> I ran the performance benchmark on an IBM machine with the following
> harddrive attached to it.
>
> cat /proc/ide/hda/model
> ST340014A
Ok, so plain IDE.
> Also note the CSCAN implementation is using rbtrees due which the time
> complexity of the different operations is O(log(n)) and not O(n) and
> that might be the reason that we are getting good values for specially
> in case of sequential writes and the random workloads.
Extremely unlikely. The sort overhead is completely noise in a test such
as yours, an O(n^2) would likely run just as fast.
--
Jens Axboe
next prev parent reply other threads:[~2006-06-12 6:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-09 19:30 CSCAN vs CFQ I/O scheduler benchmark results Vishal Patil
2006-06-10 2:15 ` Vishal Patil
2006-06-11 10:09 ` Jan Engelhardt
2006-06-11 18:58 ` Jens Axboe
2006-06-11 23:47 ` Vishal Patil
2006-06-12 6:41 ` Jens Axboe [this message]
2006-06-12 17:38 ` Vishal Patil
2006-06-12 22:21 ` Nate Diller
2006-06-13 5:46 ` Jens Axboe
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