From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] Fix aic7xxx del_timer_sync() deadlock Date: Sun, 29 Feb 2004 14:00:17 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <404236C1.5000001@pobox.com> References: <1077906383.2157.98.camel@mulgrave> <3462370000.1077909838@aslan.btc.adaptec.com> <403FFF86.90302@pobox.com> <20040228092512.GD923@suse.de> <4041292C.3090700@pobox.com> <20040229091350.GC3149@suse.de> <137982704.1078081053@aslan.btc.adaptec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:41420 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S262107AbUB2TAb (ORCPT ); Sun, 29 Feb 2004 14:00:31 -0500 In-Reply-To: <137982704.1078081053@aslan.btc.adaptec.com> List-Id: linux-scsi@vger.kernel.org To: "Justin T. Gibbs" Cc: Jens Axboe , James Bottomley , SCSI Mailing List , Andrew Morton Justin T. Gibbs wrote: >>>That would imply that blk_start_queue() is OK when there is no more I/O >>>pending... >> >>That is the model. The problem is that you don't have an opportunitty to >>call blk_start_queue() if there's no more IO pending (you typicall do it >>from io completion). There's no problem with doing that. > > > You just need to schedule a timer to do the blk_start_queue() call. > The point of doing this is so that the delay is deterministic. Now that I understand what Jens is referring to... this depends on the LLD. In network drivers (from which the model I speak of originated) and in the upcoming block-level SATA drivers, a delay not needed. The LLD calls blk_start_queue() when it is ready to receive requests -- which is not a time-based constraint. Jeff