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From: James Bottomley <James.Bottomley@SteelEye.com>
To: Jens Axboe <axboe@suse.de>
Cc: Andrew Morton <akpm@osdl.org>,
	SCSI Mailing List <linux-scsi@vger.kernel.org>,
	aradford@amcc.com, Nick Orlov <bugfixer@list.ru>
Subject: Re: Fw: 2.6.12-mm2: 3ware SATA RAID inaccessible
Date: Mon, 27 Jun 2005 09:22:28 -0500	[thread overview]
Message-ID: <1119882148.5175.13.camel@mulgrave> (raw)
In-Reply-To: <20050627075255.GK19550@suse.de>

On Mon, 2005-06-27 at 09:52 +0200, Jens Axboe wrote:
> This wont work at all, I'm afraid. You cannot atomically kmap() the
> buffer for queueing, and unmap it from interrupt context. The type
> probably isn't correct, and you are not guaranteed to be on the same
> CPU when doing the unmap. Thus you end up with corrupted maps and
> preemption counts.

Actually, it's a lot simpler than that.  We're generating the data for
the command, so all we do is send an equivalent command to the array (if
any) and then in the irq routine, kmap_atomic the buffer, copy the array
data into the buffer in the right order for the command then kunmap the
buffer again.  This should work fine, I think.

James



  reply	other threads:[~2005-06-27 14:22 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-26 22:39 Fw: 2.6.12-mm2: 3ware SATA RAID inaccessible Andrew Morton
2005-06-26 23:37 ` James Bottomley
2005-06-27  4:46   ` Nick Orlov
2005-06-27 14:22     ` James Bottomley
2005-06-28  2:08       ` Nick Orlov
2005-06-28  4:05         ` James Bottomley
2005-06-28 11:02           ` Nick Orlov
2005-06-28 12:09             ` Jens Axboe
2005-06-28 14:18               ` James Bottomley
2005-06-28 14:23                 ` Jens Axboe
2005-06-29  1:58                   ` Nick Orlov
2005-06-27  7:52   ` Jens Axboe
2005-06-27 14:22     ` James Bottomley [this message]
2005-06-27 14:27       ` Jens Axboe
2005-06-28  8:25   ` Jens Axboe

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