From: Robert Hancock <hancockrwd@gmail.com>
To: linux-scsi@vger.kernel.org
Cc: linux-ide@vger.kernel.org
Subject: Re: LSF Papers online?
Date: Tue, 14 Apr 2009 19:39:50 -0600 [thread overview]
Message-ID: <49E53AE6.4010803@gmail.com> (raw)
In-Reply-To: <1239749357.3638.3.camel@mulgrave>
James Bottomley wrote:
>
> On a final note about the urgency of getting libata out of SCSI: Intel
> has been worrying for a while about the fatness of the SCSI/libata
> stack, and its effects on performance, especially command transmission
> via SAT, so I'm hoping they'll be supporting the effort.
I really don't see this as being a big driver for this move. If you look
at the code that does the translation of SCSI commands to ATA commands,
there really is not much there at all of any consequence to CPU usage.
Compared to any kind of hardware/controller interactions I wouldn't say
it's likely to be a significant bottleneck at all. In oprofile runs I've
done with heavy ATA activity, the top time consumers are the interrupt
handlers, command issue paths, code that actually is poking IO
registers. The libata-scsi code hasn't even shown up on the radar in my
experience.
next prev parent reply other threads:[~2009-04-15 1:40 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-13 12:53 LSF Papers online? Boaz Harrosh
2009-04-13 13:58 ` James Bottomley
2009-04-13 14:42 ` Boaz Harrosh
2009-04-13 14:51 ` James Bottomley
2009-04-13 15:19 ` Chris Mason
2009-04-13 15:44 ` Boaz Harrosh
2009-04-13 16:45 ` Theodore Tso
2009-04-13 18:11 ` Jonathan Corbet
2009-04-13 20:05 ` Nicholas A. Bellinger
2009-04-13 21:40 ` Bartlomiej Zolnierkiewicz
2009-04-13 21:49 ` Bartlomiej Zolnierkiewicz
2009-04-13 22:24 ` Jeff Garzik
2009-04-14 1:24 ` Bartlomiej Zolnierkiewicz
2009-04-14 10:14 ` Jeff Garzik
2009-04-14 14:54 ` Bartlomiej Zolnierkiewicz
2009-04-14 15:40 ` Jeff Garzik
2009-04-14 16:54 ` Alan Cox
2009-04-14 22:09 ` Bartlomiej Zolnierkiewicz
2009-04-14 22:49 ` James Bottomley
2009-04-15 1:39 ` Robert Hancock [this message]
2009-04-15 3:58 ` James Bottomley
2009-04-15 8:30 ` Alan Cox
2009-04-16 6:31 ` Grant Grundler
2009-04-16 16:37 ` James Bottomley
2009-04-16 17:45 ` Matthew Wilcox
2009-04-14 23:14 ` Jeff Garzik
2009-04-15 9:28 ` Alan Cox
2009-04-15 13:38 ` Bartlomiej Zolnierkiewicz
2009-04-15 14:56 ` Alan Cox
2009-04-16 16:01 ` Bartlomiej Zolnierkiewicz
2009-04-14 3:30 ` Tejun Heo
2009-04-14 14:47 ` Bartlomiej Zolnierkiewicz
2009-04-16 21:36 ` Grant Grundler
2009-04-17 4:44 ` Martin K. Petersen
2009-04-18 4:06 ` Grant Grundler
2009-04-19 11:00 ` Boaz Harrosh
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