Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933162AbbGJT5x (ORCPT ); Fri, 10 Jul 2015 15:57:53 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:19677 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933111AbbGJT5q (ORCPT ); Fri, 10 Jul 2015 15:57:46 -0400 Date: Fri, 10 Jul 2015 15:57:14 -0400 From: Konrad Rzeszutek Wilk To: Bob Liu Cc: linux-kernel@vger.kernel.org, axboe@fb.com, hch@infradead.org, xen-devel@lists.xenproject.org, avanzini.arianna@gmail.com, david.vrabel@citrix.com, marcus.granado@citrix.com, roger.pau@citrix.com Subject: Re: [RESEND PATCH] xen/blkfront: convert to blk-mq APIs Message-ID: <20150710195714.GB31146@l.oracle.com> References: <1436176608-18237-1-git-send-email-bob.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436176608-18237-1-git-send-email-bob.liu@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1406 Lines: 41 On Mon, Jul 06, 2015 at 05:56:48PM +0800, Bob Liu wrote: > From: Arianna Avanzini > > This patch converts xen-blkfront driver to use the block multiqueue APIs. > Only one hardware queue is used now, so there is no performance change. > > The legacy non-mq code was deleted completely which is the same as other drivers > like virtio, mtip, and nvme. > > Also dropped unnecessary holding of info->io_lock when calling into blk-mq APIs. Yeey! Two points: - The io_lock is now used to guard against concurrent access to the ring. We should rename it to 'ring_lock'. - The kick_pending_request_queues should have an extra argument - 'bool locked'. This is so that you don't drop and immediately grab the lock from the blkif_interrupt. See: > @@ -1243,9 +1243,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) > } else > info->ring.sring->rsp_event = i + 1; > > - kick_pending_request_queues(info); > - > spin_unlock_irqrestore(&info->io_lock, flags); > + kick_pending_request_queues(info); > > return IRQ_HANDLED; > } Otherwise Reviewed-by: Konrad Rzeszutek Wilk -- 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/