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=MAILING_LIST_MULTI,SPF_PASS, 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 222FDC0044C for ; Thu, 1 Nov 2018 10:27:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD9942081B for ; Thu, 1 Nov 2018 10:27:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD9942081B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728098AbeKAT34 (ORCPT ); Thu, 1 Nov 2018 15:29:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:58274 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726520AbeKAT34 (ORCPT ); Thu, 1 Nov 2018 15:29:56 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D6348AD94; Thu, 1 Nov 2018 10:27:34 +0000 (UTC) Date: Thu, 1 Nov 2018 11:27:34 +0100 From: Michal Hocko To: Miles Chen Cc: Andrew Morton , Joe Perches , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com Subject: Re: [PATCH v3] mm/page_owner: use kvmalloc instead of kmalloc Message-ID: <20181101102734.GF23921@dhcp22.suse.cz> References: <20181029081706.GC32673@dhcp22.suse.cz> <1540862950.12374.40.camel@mtkswgap22> <20181030060601.GR32673@dhcp22.suse.cz> <1540882551.23278.12.camel@mtkswgap22> <20181030081537.GV32673@dhcp22.suse.cz> <1540975637.10275.10.camel@mtkswgap22> <20181031101501.GL32673@dhcp22.suse.cz> <1540981182.16084.1.camel@mtkswgap22> <20181031114107.GM32673@dhcp22.suse.cz> <1541066412.31492.10.camel@mtkswgap22> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1541066412.31492.10.camel@mtkswgap22> 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 Thu 01-11-18 18:00:12, Miles Chen wrote: [...] > I did a test today, the only code changed is to clamp to read count to > PAGE_SIZE and it worked well. Maybe we can solve this issue by just > clamping the read count. > > count = count > PAGE_SIZE ? PAGE_SIZE : count; This i what Matthew was proposing AFAIR. At least as a stop gap solution. Maybe we want to extend this to a more standard implementation later on (e.g. seq_file). -- Michal Hocko SUSE Labs