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=-0.8 required=3.0 tests=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 D8565C433DF for ; Tue, 16 Jun 2020 02:25:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4F3220707 for ; Tue, 16 Jun 2020 02:25:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="fACpV1lG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726387AbgFPCZr (ORCPT ); Mon, 15 Jun 2020 22:25:47 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:43346 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726101AbgFPCZp (ORCPT ); Mon, 15 Jun 2020 22:25:45 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 05G2M3UG064702; Tue, 16 Jun 2020 02:25:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : message-id : references : date : in-reply-to : mime-version : content-type; s=corp-2020-01-29; bh=VlICDy7edvgzVgA+O0X0Ww8RKymsFN+Ai0i5tfOaRa8=; b=fACpV1lG+HEmDBx7BgF48E5lH3PruiGloSqoMHAfh1KBV9X9fELRCkceLtMOViXKLR7k niXtB7JY4jz4SU6NPetTt7d9qT0xMz4ZN7DpSopeuWLk08TLUB1/SjE/ZcJf19+lwgbD JnLvx80wZuTk4zwpDOAgophWMz0OyPllK+M8W0anQKQak8/oT6vbX+Eyo/FELnqHFlJT g/ffMObppU2mqCqq09DDBKAp7GmU0vs26ZYb5ECqJJEMR0IfkFe8RzGrV7dpffoQEpeK hbWGlfNPI2/l0zy6UWaLpyLPz1rD1QbBLAA5JYM5qb5e10wvg7GOGIMB+8yhYqHSKEaI FQ== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 31p6s241qv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 16 Jun 2020 02:25:33 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 05G2N2FB009258; Tue, 16 Jun 2020 02:25:32 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 31p6s6f286-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Jun 2020 02:25:32 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 05G2PVYx015589; Tue, 16 Jun 2020 02:25:31 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 15 Jun 2020 19:25:30 -0700 To: John Dorminy Cc: Harshad Shirwadkar , linux-block@vger.kernel.org, tytso@mit.edu, "Martin K. Petersen" Subject: Re: [PATCH] block: add split_alignment for request queue From: "Martin K. Petersen" Organization: Oracle Corporation Message-ID: References: <20200616005633.172804-1-harshadshirwadkar@gmail.com> Date: Mon, 15 Jun 2020 22:25:27 -0400 In-Reply-To: (John Dorminy's message of "Mon, 15 Jun 2020 22:14:05 -0400") MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9653 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 malwarescore=0 mlxscore=0 suspectscore=1 mlxlogscore=999 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006160015 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9653 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 impostorscore=0 clxscore=1011 mlxscore=0 mlxlogscore=999 priorityscore=1501 phishscore=0 malwarescore=0 suspectscore=1 spamscore=0 cotscore=-2147483648 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006160015 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org John, > Reading through this change, split_alignment appears similar in my > mind to limits->io_opt. io_opt is a hint which requests that the submitter does not issue any I/Os that are larger than this size. io_opt is smaller than or equal to the device's hard limit for I/O size. In the standards space it's described as "issuing an I/O larger than this value may incur a processing penalty". So not quite what you're looking for. However, we have chunk_sectors queue limit which is honored for splits. -- Martin K. Petersen Oracle Linux Engineering