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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 051C2C4332F for ; Thu, 17 Mar 2022 01:09:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355854AbiCQBKi (ORCPT ); Wed, 16 Mar 2022 21:10:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242548AbiCQBKh (ORCPT ); Wed, 16 Mar 2022 21:10:37 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B8DE11D303 for ; Wed, 16 Mar 2022 18:09:21 -0700 (PDT) Received: from [10.20.42.25] (unknown [10.20.42.25]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dx3888ijJiA4cKAA--.31540S3; Thu, 17 Mar 2022 09:09:17 +0800 (CST) Subject: Re: [PATCH] mm: add access/dirty bit on numa page fault To: Anshuman Khandual , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220316010836.1137084-1-maobibo@loongson.cn> <93302a47-9fda-25c7-4212-41b8dd027696@arm.com> <3756661c-d710-7bf6-76ab-39ac44f8e8b3@loongson.cn> From: maobibo Message-ID: <4bb3e4ef-29f9-448b-22ad-1ae7c2d008ff@loongson.cn> Date: Thu, 17 Mar 2022 09:09:16 +0800 User-Agent: Mozilla/5.0 (X11; Linux mips64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CM-TRANSID: AQAAf9Dx3888ijJiA4cKAA--.31540S3 X-Coremail-Antispam: 1UD129KBjvdXoWrtF4DuryruFWftw18uFyDKFg_yoWDGwc_ua 1F9w4qk3WDtFnFk3Wvvr45J39xXa1DJry5tr4jgryIg343J3yUGr93WrZYqFs8GFsrtFWU Grn0vr43Z3ZIqjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbxkYjsxI4VWkKwAYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM2 8CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0 cI8IcVCY1x0267AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I 8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lc7I2V7IY0VAS07AlzVAYIcxG8wCY 02Avz4vE-syl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4 xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1D MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I 0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE14v2 6r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU5 PpnJUUUUU== X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/16/2022 05:42 PM, Anshuman Khandual wrote: > > > On 3/16/22 12:33, maobibo wrote: >> >> On 03/16/2022 02:43 PM, Anshuman Khandual wrote: >>> >>> On 3/16/22 06:38, Bibo Mao wrote: >>>> During numa page fault, dirty bit can be added for old pte if >>>> fail to migrate on write fault. And if it succeeds to migrate, >>>> access bit can be added for migrated new pte, also dirty bit >>>> can be added for write fault. >>> The current code does not set the access and dirty bits when ever >>> applicable i.e on FAULT_FLAG_WRITE, on the pte (old if migration >>> fails, new if migration succeeds) ? Did not this cause any problem >>> earlier ? I am wondering how this might have gone unnoticed. > >> On arm/x86 platform hw will set access/dirty bits automatically, >> however on MIPS platform access/dirty bits are set by software in next >> page fault, it is relatively easier to watch on MIPS platform. > > Could you please update this in the commit message as well ? sure, will do. regards bibo, mao