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 59A0DC33C9E for ; Fri, 31 Jan 2020 02:19:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 367E8206F0 for ; Fri, 31 Jan 2020 02:19:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727887AbgAaCTM (ORCPT ); Thu, 30 Jan 2020 21:19:12 -0500 Received: from mail104.syd.optusnet.com.au ([211.29.132.246]:52634 "EHLO mail104.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727749AbgAaCTM (ORCPT ); Thu, 30 Jan 2020 21:19:12 -0500 Received: from dread.disaster.area (pa49-195-111-217.pa.nsw.optusnet.com.au [49.195.111.217]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id 78756820118; Fri, 31 Jan 2020 13:19:10 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1ixLtl-0006PJ-WF; Fri, 31 Jan 2020 13:19:10 +1100 Date: Fri, 31 Jan 2020 13:19:09 +1100 From: Dave Chinner To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 11/12] fuse: Convert from readpages to readahead Message-ID: <20200131021909.GC18575@dread.disaster.area> References: <20200125013553.24899-1-willy@infradead.org> <20200125013553.24899-12-willy@infradead.org> <20200129010829.GK18610@dread.disaster.area> <20200130213533.GN6615@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200130213533.GN6615@bombadil.infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=W5xGqiek c=1 sm=1 tr=0 a=0OveGI8p3fsTA6FL6ss4ZQ==:117 a=0OveGI8p3fsTA6FL6ss4ZQ==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=Jdjhy38mL1oA:10 a=7-415B0cAAAA:8 a=6Pvhz1k-dUzALmsgqCgA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Jan 30, 2020 at 01:35:33PM -0800, Matthew Wilcox wrote: > On Wed, Jan 29, 2020 at 12:08:29PM +1100, Dave Chinner wrote: > > On Fri, Jan 24, 2020 at 05:35:52PM -0800, Matthew Wilcox wrote: > > > + while (nr_pages--) { > > > + struct page *page = readahead_page(mapping, start++); > > > + int err = fuse_readpages_fill(&data, page); > > > + > > > + if (!err) > > > + continue; > > > + nr_pages++; > > > + goto out; > > > } > > > > That's some pretty convoluted logic. Perhaps: > > > > for (; nr_pages > 0 ; nr_pages--) { > > struct page *page = readahead_page(mapping, start++); > > > > if (fuse_readpages_fill(&data, page)) > > goto out; > > } > > I have a bit of an aversion to that style of for loop ... I like this > instead: > > while (nr_pages) { > struct page *page = readahead_page(mapping, start++); > > if (fuse_readpages_fill(&data, page) != 0) > goto out; > nr_pages--; > } yup, that's also fine. -Dave. -- Dave Chinner david@fromorbit.com