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=-4.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no 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 1BB1CC433E1 for ; Tue, 25 Aug 2020 22:14:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7B6420706 for ; Tue, 25 Aug 2020 22:14:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="lYVNsW7b" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726610AbgHYWO3 (ORCPT ); Tue, 25 Aug 2020 18:14:29 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:43344 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726471AbgHYWO1 (ORCPT ); Tue, 25 Aug 2020 18:14:27 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 07PM9nN5171494; Tue, 25 Aug 2020 22:14:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=n+SDM3E28nCnOj/ZIdYxllNKqwlO0WVL977/aXzCToM=; b=lYVNsW7bRgguHLyVdZRvbHXMwu8efoU7zXQ4RCyySuj1uHi21FUYr8brkWIgSRe2dwqe o6Vfz6U006JdqRAiS/8CySQBaXR+rM3xiNwOVnIZk7KZOkHEy9j+NUjb7W8Ua7nMK8k6 X/mkGh8cK7lVJ9GoMCemSwGdwzolgXDMN8Tk43iyJpL1kIvgEhvhU8Wt2y4D9UvKytN+ kGifzHOwQ+TifMMygaqqkgReDs6cA1gJj5A0nwivtp4AsPllQAC/HTCe2O3UL/5rKliz wFORPcFoC3kFuvwY4dTqf6CjE1CyJGDOsg0geDjvc6Qh4iDFrXB12eJ0qJ7IzKd7nnnr Ew== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 333dbrw6y6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 25 Aug 2020 22:14:21 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 07PMAbwF110146; Tue, 25 Aug 2020 22:14:21 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3020.oracle.com with ESMTP id 333rtyccw0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 25 Aug 2020 22:14:21 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 07PMEHkx010818; Tue, 25 Aug 2020 22:14:17 GMT Received: from localhost (/10.159.234.29) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 25 Aug 2020 15:14:17 -0700 Date: Tue, 25 Aug 2020 15:14:16 -0700 From: "Darrick J. Wong" To: Dave Chinner Cc: "Matthew Wilcox (Oracle)" , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/9] iomap: Convert read_count to byte count Message-ID: <20200825221416.GK6096@magnolia> References: <20200824145511.10500-1-willy@infradead.org> <20200824145511.10500-7-willy@infradead.org> <20200825000902.GG12131@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200825000902.GG12131@dread.disaster.area> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9724 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 adultscore=0 phishscore=0 spamscore=0 bulkscore=0 mlxlogscore=999 malwarescore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008250166 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9724 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 clxscore=1015 priorityscore=1501 impostorscore=0 phishscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 mlxscore=0 lowpriorityscore=0 suspectscore=1 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008250166 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Aug 25, 2020 at 10:09:02AM +1000, Dave Chinner wrote: > On Mon, Aug 24, 2020 at 03:55:07PM +0100, Matthew Wilcox (Oracle) wrote: > > Instead of counting bio segments, count the number of bytes submitted. > > This insulates us from the block layer's definition of what a 'same page' > > is, which is not necessarily clear once THPs are involved. > > I'd like to see a comment on the definition of struct iomap_page to > indicate that read_count (and write count) reflect the byte count of > IO currently in flight on the page, not an IO count, because THP > makes tracking this via bio state hard. Otherwise it is not at all > obvious why it is done and why it is intentional... Agreed. :) --D > Otherwise the code looks OK. > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com