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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A6E62C5DF65 for ; Wed, 6 Nov 2019 17:23:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D59C21848 for ; Wed, 6 Nov 2019 17:23:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732330AbfKFRXE (ORCPT ); Wed, 6 Nov 2019 12:23:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:48946 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729259AbfKFRXE (ORCPT ); Wed, 6 Nov 2019 12:23:04 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id B5790B498; Wed, 6 Nov 2019 17:23:02 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 546B61E4353; Wed, 6 Nov 2019 18:23:02 +0100 (CET) Date: Wed, 6 Nov 2019 18:23:02 +0100 From: Jan Kara To: Ritesh Harjani Cc: tytso@mit.edu, jack@suse.cz, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, mbobrowski@mbobrowski.org Subject: Re: [RFC 0/5] Ext4: Add support for blocksize < pagesize for dioread_nolock Message-ID: <20191106172302.GE12685@quack2.suse.cz> References: <20191016073711.4141-1-riteshh@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191016073711.4141-1-riteshh@linux.ibm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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 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. Honza -- Jan Kara SUSE Labs, CR