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=-0.7 required=3.0 tests=FORGED_MUA_MOZILLA, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 36539FA372C for ; Thu, 7 Nov 2019 11:16:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 076712187F for ; Thu, 7 Nov 2019 11:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388487AbfKGLQZ (ORCPT ); Thu, 7 Nov 2019 06:16:25 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:26030 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388178AbfKGLQZ (ORCPT ); Thu, 7 Nov 2019 06:16:25 -0500 Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xA7B8x0g035074 for ; Thu, 7 Nov 2019 06:16:23 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w41w6wtdb-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 07 Nov 2019 06:16:22 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 7 Nov 2019 11:16:01 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xA7BG0dv64356470 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 7 Nov 2019 11:16:00 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 04EA6A4053; Thu, 7 Nov 2019 11:16:00 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DEC5FA4059; Thu, 7 Nov 2019 11:15:58 +0000 (GMT) Received: from [9.199.158.214] (unknown [9.199.158.214]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 7 Nov 2019 11:15:58 +0000 (GMT) Subject: Re: [RFC 0/5] Ext4: Add support for blocksize < pagesize for dioread_nolock To: Jan Kara Cc: tytso@mit.edu, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, mbobrowski@mbobrowski.org References: <20191016073711.4141-1-riteshh@linux.ibm.com> <20191106172302.GE12685@quack2.suse.cz> From: Ritesh Harjani Date: Thu, 7 Nov 2019 16:45:58 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20191106172302.GE12685@quack2.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19110711-0028-0000-0000-000003B383DA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19110711-0029-0000-0000-00002475E350 Message-Id: <20191107111558.DEC5FA4059@d06av23.portsmouth.uk.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-07_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911070114 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 11/6/19 10:53 PM, Jan Kara wrote: > On Wed 16-10-19 13:07:06, Ritesh Harjani wrote: >> This patch series adds the support for blocksize < pagesize for >> dioread_nolock feature. >> >> Since in case of blocksize < pagesize, we can have multiple >> small buffers of page as unwritten extents, we need to >> maintain a vector of these unwritten extents which needs >> the conversion after the IO is complete. Thus, we maintain >> a list of tuple pair (io_end_vec) for this & >> traverse this list to do the unwritten to written conversion. >> >> Appreciate any reviews/comments on this patches. > > I know Ted has merged the patches already so this is just informational but > I've read the patches and they look fine to me. Thanks for the work! I was Appreciate your help too for valuable feedback & pointers at various places. > just thinking that we could actually make the vector tracking more > efficient because the io_end always looks like: > > one-big-extent-to-fully-write + whatever it takes to fully write out the > last page > > So your vectors could be also expressed as "extent to write" + bitmap of > blocks written in the last page. And 64-bits are enough for the bitmap for > anything ext4 supports so we could easily save allocation of ioend_vec etc. > Just a suggestion. Yes, sounds good to me. Although slab allocations are also fast. However I agree this should be more efficient and will also avoid the list management and or list pointer traversal. Sure, will work over this optimization once I get some closure on some ongoing open items. Thanks & appreciate your feedback. ritesh