From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
To: "'Andrew Morton'" <akpm@osdl.org>
Cc: <linux-kernel@vger.kernel.org>, <axboe@suse.de>
Subject: RE: Direct io on block device has performance regression on 2.6.x kernel
Date: Wed, 9 Mar 2005 17:44:54 -0800 [thread overview]
Message-ID: <200503100144.j2A1isg28121@unix-os.sc.intel.com> (raw)
In-Reply-To: <20050309173351.0d69de25.akpm@osdl.org>
Andrew Morton wrote on Wednesday, March 09, 2005 5:34 PM
> What are these percentages? Total CPU time? The direct-io stuff doesn't
> look too bad. It's surprising that tweaking the direct-io submission code
> makes much difference.
Percentage is relative to total kernel time. There are three DIO functions
showed up in the profile:
__blockdev_direct_IO 4.97%
dio_bio_end_io 2.70%
dio_bio_complete 1.20%
> hm. __blockdev_direct_IO() doesn't actually do much. I assume your damn
> compiler went and inlined direct_io_worker() on us.
We are using gcc version 3.4.3. I suppose I can finger point gcc ? :-P
- Ken
next prev parent reply other threads:[~2005-03-10 1:49 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-09 1:39 Chen, Kenneth W
2005-03-09 6:27 ` Andrew Morton
2005-03-09 17:21 ` Chen, Kenneth W
2005-03-09 20:04 ` Andrew Morton
2005-03-09 21:59 ` Chen, Kenneth W
2005-03-09 22:44 ` Andrew Morton
2005-03-10 1:11 ` Chen, Kenneth W
2005-03-10 1:33 ` Andrew Morton
2005-03-10 1:44 ` Chen, Kenneth W [this message]
2005-03-10 2:25 ` Andrew Morton
2005-03-10 3:47 ` Chen, Kenneth W
2005-03-10 4:04 ` David Lang
2005-03-10 4:10 ` Andrew Morton
2005-03-10 4:15 ` Direct io on block device has performance regression on 2.6.xkernel David Lang
2005-03-10 4:09 ` Direct io on block device has performance regression on 2.6.x kernel Andrew Morton
2005-03-10 18:31 ` Chen, Kenneth W
2005-03-10 20:30 ` Andrew Morton
2005-03-10 21:42 ` Chen, Kenneth W
2005-03-10 22:01 ` Andrew Morton
2005-03-10 4:28 ` Andrew Vasquez
2005-03-09 1:53 Chen, Kenneth W
2005-03-09 22:18 Chen, Kenneth W
2005-03-09 23:23 ` Andi Kleen
2005-03-09 23:52 ` Jesse Barnes
2005-03-09 23:52 ` Jesse Barnes
2005-03-10 1:00 ` Chen, Kenneth W
2005-03-10 0:57 ` Chen, Kenneth W
2005-03-10 1:24 Chen, Kenneth W
2005-03-10 2:04 Chen, Kenneth W
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