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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 45E95C10F04 for ; Thu, 14 Feb 2019 16:27:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A8BF222DA for ; Thu, 14 Feb 2019 16:27:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394137AbfBNQ1o (ORCPT ); Thu, 14 Feb 2019 11:27:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:44520 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387824AbfBNQ1n (ORCPT ); Thu, 14 Feb 2019 11:27:43 -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 4AACCAF56; Thu, 14 Feb 2019 16:27:42 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id C54271E0900; Thu, 14 Feb 2019 17:27:41 +0100 (CET) Date: Thu, 14 Feb 2019 17:27:41 +0100 From: Jan Kara To: Matthew Wilcox Cc: Jan Kara , "Kirill A . Shutemov" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Hugh Dickins , William Kucharski Subject: Re: [PATCH v2] page cache: Store only head pages in i_pages Message-ID: <20190214162741.GA23000@quack2.suse.cz> References: <20190212183454.26062-1-willy@infradead.org> <20190213144102.GA18351@quack2.suse.cz> <20190213201715.GU12668@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190213201715.GU12668@bombadil.infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 13-02-19 12:17:15, Matthew Wilcox wrote: > > > - pages[ret] = page; > > > + pages[ret] = find_subpage(page, xas.xa_index); > > > if (++ret == nr_pages) { > > > *start = page->index + 1; > > > goto out; > > > } > > > > So this subtly changes the behavior because now we will be returning in > > '*start' a different index. So you should rather use 'pages[ret]->index' > > instead. > > You're right, I made a mistake there. However, seeing this: > https://lore.kernel.org/lkml/20190110030838.84446-1-yuzhao@google.com/ > > makes me think that I should be using xa_index + 1 there. Yeah, you're right. Thanks! Honza -- Jan Kara SUSE Labs, CR