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[195.135.220.15]) by mx.google.com with ESMTPS id w4si1320608edh.354.2019.02.14.08.27.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Feb 2019 08:27:42 -0800 (PST) Received-SPF: pass (google.com: domain of jack@suse.cz designates 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=pass (google.com: domain of jack@suse.cz designates 195.135.220.15 as permitted sender) smtp.mailfrom=jack@suse.cz 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) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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