Re: [PATCH] as i/o hang with aacraid driver 2.6.0-test1

From: Mark Haverkamp <markh@osdl.org>
To: James Bottomley <James.Bottomley@steeleye.com>
Cc: Nick Piggin <piggin@cyberone.com.au>,
	Andrew Morton <akpm@osdl.org>, Daniel McNeil <daniel@osdl.org>,
	Jens Axboe <axboe@suse.de>, Cliff White <cliffw@osdl.org>,
	linux-scsi <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH] as i/o hang with aacraid driver 2.6.0-test1
Date: 18 Jul 2003 13:45:57 -0700	[thread overview]
Message-ID: <1058561157.20130.99.camel@markh1.pdx.osdl.net> (raw)
In-Reply-To: <1058559719.1826.106.camel@mulgrave>

On Fri, 2003-07-18 at 13:21, James Bottomley wrote:
> On Fri, 2003-07-18 at 12:46, Mark Haverkamp wrote:
> > I'll try out your test harness on our hardware and see what happens.
> 
> OK, I think I found the problem.
> 
> Parts of the SCSI and block code don't distinguish between queueing and
> requeueing, so they trip over the exact same error.
> 
> The (fairly invasive) fix is to add an extra parameter to
> blk_insert_request to tell it if this is a reinsertion or a new request
> (patch attached--against Jens' previous one).
> 
> With this, I now get the AS ioscheduler to survive my tests.
> 
> Incidentally, I'm not sure whether scsi_requeue_command() counts as a
> reinsertion.  It's used to redo I/O after end_that_request_first() but
> before end_that_request_last().
> 
> James

James,

I had just set my machine up with your test harness in the aacraid
driver and was able to get hangs after a short time.  I applied your
patch and now the hangs seem to be gone for me too.

Mark.
-- 
Mark Haverkamp <markh@osdl.org>