From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756674AbaHVPDL (ORCPT ); Fri, 22 Aug 2014 11:03:11 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:60540 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756290AbaHVPDJ (ORCPT ); Fri, 22 Aug 2014 11:03:09 -0400 Date: Fri, 22 Aug 2014 08:03:07 -0700 From: Christoph Hellwig To: David Vrabel Cc: Arianna Avanzini , konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, bob.liu@oracle.com, felipe.franciosi@citrix.com, axboe@fb.com Subject: Re: [PATCH RFC 1/4] xen, blkfront: add support for the multi-queue block layer API Message-ID: <20140822150307.GB29424@infradead.org> References: <1408706404-6614-1-git-send-email-avanzini.arianna@gmail.com> <1408706404-6614-2-git-send-email-avanzini.arianna@gmail.com> <53F736BE.9010202@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53F736BE.9010202@citrix.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 22, 2014 at 01:25:34PM +0100, David Vrabel wrote: > > + spin_lock_irq(&info->io_lock); > > Is this lock necessary? Does the block layer serialise calls to the > queue_rq op? Calls to ->queue_rq are not serialized by the block layer.