Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751299AbbGKSPf (ORCPT ); Sat, 11 Jul 2015 14:15:35 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:24694 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751010AbbGKSPe (ORCPT ); Sat, 11 Jul 2015 14:15:34 -0400 Message-ID: <55A15D22.4020709@fb.com> Date: Sat, 11 Jul 2015 12:14:58 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Bob Liu , CC: , , , , , , Subject: Re: [PATCH v2] xen/blkfront: convert to blk-mq APIs References: <1436621418-6742-1-git-send-email-bob.liu@oracle.com> In-Reply-To: <1436621418-6742-1-git-send-email-bob.liu@oracle.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.54.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-07-11_10:2015-07-11,2015-07-11,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1445 Lines: 43 On 07/11/2015 07:30 AM, Bob Liu wrote: > Note: This patch is based on original work of Arianna's internship for > GNOME's Outreach Program for Women. Great to see this finally get prepped to go in! > Only one hardware queue is used now, so there is no performance change. I would hope that the blk-mq path, even with one queue, is a perf win over the old interface. So I'm not sure that is correct. But the bigger win will be with more queues, of course. > The legacy non-mq code is deleted completely which is the same as other > drivers like virtio, mtip, and nvme. > > Also dropped one unnecessary holding of info->io_lock when calling > blk_mq_stop_hw_queues(). > > Changes in v2: > - Reorganized blk_mq_queue_rq() > - Restored most io_locks in place Looks good to me. The most common error case is the busy-out not stopping queues, or not restarting them at completion. But that all looks fine. I would, however, rename blk_mq_queue_rq(). It sounds like a core function. blkif_queue_rq() would be more appropriate. > Signed-off-by: Arianna Avanzini > Signed-off-by: Bob Liu Acked-by: Jens Axboe -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/