From: James Bottomley <James.Bottomley@SteelEye.com>
To: Doug Chapman <doug.chapman@hp.com>
Cc: eric.moore@lsi.com, linux-scsi@vger.kernel.org
Subject: Re: [PATCH] fix for BZ 8426 - massive slowdown on SCSI CD/DVD drive connected to mptspi driver
Date: Tue, 22 May 2007 16:27:14 -0500 [thread overview]
Message-ID: <1179869235.3738.55.camel@mulgrave.il.steeleye.com> (raw)
In-Reply-To: <1179865510.5479.17.camel@phobos>
On Tue, 2007-05-22 at 14:25 -0600, Doug Chapman wrote:
> Eric,
>
> Sorry to bother you on this again, I realize you are very busy.
>
> >From our off-list email and from your comments to Chip Coldwell in
> redhat BZ 225177 it sounded like you were prepared to ACK this. Any
> chance you could send your official ACK so this can be committed?
>
> much appreciated,
Actually I'd like a little analysis of why first, please Eric.
It seems to me, with the current wrong ordering in the initialisation
results in a large queue depth being given to the DVD (which are
habitually very low queue depth ... or even untagged beasts). So does
the slowdown result from the fusion accepting N commands for the DVD and
then rejecting N-1 of them resulting in ping pong between the mid-layer
and driver?
If so, we probably want to fix the command throttling in the driver.
James
next prev parent reply other threads:[~2007-05-22 21:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-07 19:59 [PATCH] fix for BZ 8426 - massive slowdown on SCSI CD/DVD drive connected to mptspi driver Doug Chapman
2007-05-10 13:30 ` Doug Chapman
2007-05-22 20:25 ` Doug Chapman
2007-05-22 21:27 ` James Bottomley [this message]
2007-05-29 21:40 ` [PATCH] fix for BZ 8426 - massive slowdown on SCSI CD/DVDdrive " Moore, Eric
2007-05-29 22:02 ` James Bottomley
2007-05-29 22:46 ` [PATCH] fix for BZ 8426 - massive slowdown on SCSI CD/DVDdriveconnected " Moore, Eric
2007-05-31 15:40 ` Moore, Eric
2007-05-31 16:14 ` James Bottomley
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