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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,UNPARSEABLE_RELAY 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 3AC94C4360F for ; Wed, 3 Apr 2019 02:57:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F20D12084B for ; Wed, 3 Apr 2019 02:57:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="sZBLv6WX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726670AbfDCC5v (ORCPT ); Tue, 2 Apr 2019 22:57:51 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:35348 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbfDCC5v (ORCPT ); Tue, 2 Apr 2019 22:57:51 -0400 X-Greylist: delayed 742 seconds by postgrey-1.27 at vger.kernel.org; Tue, 02 Apr 2019 22:57:50 EDT Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x332sdmD077761; Wed, 3 Apr 2019 02:57:36 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : references : date : in-reply-to : message-id : mime-version : content-type; s=corp-2018-07-02; bh=3QNUYX/6CiPJimN19TLvqEDYljNHcDYiKAec+w9jsk0=; b=sZBLv6WXTh457gmNEHTd1YdlrdH/4ikmI6AJk9owGon5CXXKpb4vCGwYSeYk1nfWtvSV F1MI7WOgl1beWefYY3+lRZnObzeCkocDH513AdPyuWEVeuB35ic9xTGdsnXkqvorJcLP 1wwdm0XLoNCzMq+bVsO05qQrGBdGKSTZa8aE2wm69CK1rIIT9zGSbmCQ52atxCWABUsK HoZPLetndXT3EtcErW9znz5QOIpZLfxWOxaw4WDqrDCdxRUKhyWJ6UbjDeDfrv873XRY sU1/ej4OwkHJImQVneXrS+/qdG6PXCVB0vGlFfacMv9XaF/TfR4H9WsrbSw5EZM6BT5Z fQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 2rj0dnnf22-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 03 Apr 2019 02:57:36 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x332vYVc035843; Wed, 3 Apr 2019 02:57:36 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3020.oracle.com with ESMTP id 2rm9mht0mv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 03 Apr 2019 02:57:35 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x332vYwF011060; Wed, 3 Apr 2019 02:57:34 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 02 Apr 2019 19:57:33 -0700 To: Kanchan Joshi Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, axboe@fb.com, prakash.v@samsung.com, anshul@samsung.com, joshiiitr@gmail.com Subject: Re: [PATCH v3 7/7] fs/ext4,jbd2: add support for passing write-hint with journal From: "Martin K. Petersen" Organization: Oracle Corporation References: <1553846032-4451-1-git-send-email-joshi.k@samsung.com> <1553846032-4451-8-git-send-email-joshi.k@samsung.com> Date: Tue, 02 Apr 2019 22:57:31 -0400 In-Reply-To: <1553846032-4451-8-git-send-email-joshi.k@samsung.com> (Kanchan Joshi's message of "Fri, 29 Mar 2019 13:23:52 +0530") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9215 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=597 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904030016 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9215 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=642 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904030016 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Kanchan, > For NAND based SSDs, mixing of data with different life-time reduces > efficiency of internal garbage-collection. During FS operations, > series of journal updates will follow/precede series of data/meta > updates, causing intermixing inside SSD. By passing a write-hint with > journal, its write can be isolated from other data/meta writes, > leading to endurance/performance benefit on SSD. Why not just introduce REQ_JOURNAL and let the device driver decide how to turn that into something appropriate for the device? That's what I'll need for SCSI. Existing SCSI streams are not a good fit. -- Martin K. Petersen Oracle Linux Engineering