From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39167C43441 for ; Wed, 28 Nov 2018 07:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9CD520832 for ; Wed, 28 Nov 2018 07:16:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Z0eSQ9mu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E9CD520832 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727280AbeK1SQk (ORCPT ); Wed, 28 Nov 2018 13:16:40 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:35558 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727268AbeK1SQk (ORCPT ); Wed, 28 Nov 2018 13:16:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=5giSuqvoNJtla1IuEAfF5D+3ryGO5plKSrmnWmVxbWc=; b=Z0eSQ9muLkh5hkAspC3xrl2rq Db8OmdyTcqGxxe72UCInyprdUJamaElmB1oAMkzSmDvXY4EDI5cg4fBm1TQYv83/3bY/xuorgDLE0 PIWBLFLhDBICk3vjFTcr/DXQ4cS2zQ1xhK3AmI5ZbKIfdW9dYA4Yuotk+qLwq1op+XY9Ay1lnzmgT 0KHvtv9WurbyWz0lHnmeEiNPPmvZ2xTSdUIaR7nmy+HDDAC2d2g1Orj8TP+NJ7Xo5UyTz7LIVMz6o LilI4y+KNfKdOEoGU/knYlG5Jhme82/g7BUzrqI2r/cl14b3Ql9rV+QQzWmx6RJobXDtMSpHSv01X fLei+TPVQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gRu4n-0004NB-UK; Wed, 28 Nov 2018 07:16:01 +0000 Date: Tue, 27 Nov 2018 23:16:01 -0800 From: Christoph Hellwig To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH 3/8] blk-mq: add mq_ops->commit_rqs() Message-ID: <20181128071601.GA11774@infradead.org> References: <20181126163556.5181-1-axboe@kernel.dk> <20181126163556.5181-4-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181126163556.5181-4-axboe@kernel.dk> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Nov 26, 2018 at 09:35:51AM -0700, Jens Axboe wrote: > blk-mq passes information to the hardware about any given request being > the last that we will issue in this sequence. The point is that hardware > can defer costly doorbell type writes to the last request. But if we run > into errors issuing a sequence of requests, we may never send the request > with bd->last == true set. For that case, we need a hook that tells the > hardware that nothing else is coming right now. > > For failures returned by the drivers ->queue_rq() hook, the driver is > responsible for flushing pending requests, if it uses bd->last to > optimize that part. This works like before, no changes there. > > Signed-off-by: Jens Axboe This looks fine, but normally I would only add the method together with the actual user.. Reviewed-by: Christoph Hellwig From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@infradead.org (Christoph Hellwig) Date: Tue, 27 Nov 2018 23:16:01 -0800 Subject: [PATCH 3/8] blk-mq: add mq_ops->commit_rqs() In-Reply-To: <20181126163556.5181-4-axboe@kernel.dk> References: <20181126163556.5181-1-axboe@kernel.dk> <20181126163556.5181-4-axboe@kernel.dk> Message-ID: <20181128071601.GA11774@infradead.org> On Mon, Nov 26, 2018@09:35:51AM -0700, Jens Axboe wrote: > blk-mq passes information to the hardware about any given request being > the last that we will issue in this sequence. The point is that hardware > can defer costly doorbell type writes to the last request. But if we run > into errors issuing a sequence of requests, we may never send the request > with bd->last == true set. For that case, we need a hook that tells the > hardware that nothing else is coming right now. > > For failures returned by the drivers ->queue_rq() hook, the driver is > responsible for flushing pending requests, if it uses bd->last to > optimize that part. This works like before, no changes there. > > Signed-off-by: Jens Axboe This looks fine, but normally I would only add the method together with the actual user.. Reviewed-by: Christoph Hellwig