From: Neil Brown <neilb@suse.de>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Is BIO_RW_FAILFAST really usable?
Date: Thu, 6 Dec 2007 10:14:47 +1100 [thread overview]
Message-ID: <18263.12519.894142.682323@notabene.brown> (raw)
In-Reply-To: message from Jens Axboe on Tuesday December 4
On Tuesday December 4, jens.axboe@oracle.com wrote:
>
> Hrmpf. It looks like the SCSI layer is a little too trigger happy. Any
> chance you could try and trace where this happens?
in scsi_lib.c, in scsi_request_fn, near the top of the main
while (!blk_queue_plugged(q)) {
loop:
if (!scsi_dev_queue_ready(q, sdev)) {
if ((req->cmd_flags & REQ_FAILFAST) &&
!(req->cmd_flags & REQ_PREEMPT)) {
scsi_kill_request(req, q);
continue;
}
break;
}
If I remove the "if failfast and not preempt then kill" logic, my
problem goes away.
NeilBrown
prev parent reply other threads:[~2007-12-05 23:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-04 2:46 Is BIO_RW_FAILFAST really usable? Neil Brown
2007-12-04 3:51 ` Jeff Garzik
2007-12-04 4:19 ` Andrey Borzenkov
2007-12-04 9:13 ` Jens Axboe
2007-12-05 23:14 ` Neil Brown [this message]
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