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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 78025C32771 for ; Sun, 19 Jan 2020 01:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AC93246B1 for ; Sun, 19 Jan 2020 01:17:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727113AbgASBRM (ORCPT ); Sat, 18 Jan 2020 20:17:12 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:51814 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727070AbgASBRM (ORCPT ); Sat, 18 Jan 2020 20:17:12 -0500 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id EC87ACED00AE71D06D4D; Sun, 19 Jan 2020 09:17:07 +0800 (CST) Received: from [127.0.0.1] (10.173.220.96) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.439.0; Sun, 19 Jan 2020 09:17:01 +0800 Subject: Re: [RFC] iomap: fix race between readahead and direct write To: Jan Kara CC: , , , , , , , References: <20200116063601.39201-1-yukuai3@huawei.com> <20200116153206.GF8446@quack2.suse.cz> <20200117110536.GE17141@quack2.suse.cz> From: "yukuai (C)" Message-ID: <976d09e1-e3b5-a6a6-d159-9bdac3a7dc84@huawei.com> Date: Sun, 19 Jan 2020 09:17:00 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20200117110536.GE17141@quack2.suse.cz> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.173.220.96] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2020/1/17 19:05, Jan Kara wrote: > provide > allocation for each page separately Thank you for your response! I do understand there will be additional CPU overhead. But page is allocated in __do_page_cache_readahead(), which is called before iomap_begin(). And I did not change that. Thanks! Yu Kuai