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 DBEF0C433EF for ; Wed, 16 Mar 2022 09:42:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352077AbiCPJnt (ORCPT ); Wed, 16 Mar 2022 05:43:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232098AbiCPJnq (ORCPT ); Wed, 16 Mar 2022 05:43:46 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BAE0C65485 for ; Wed, 16 Mar 2022 02:42:32 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 47F1B1476; Wed, 16 Mar 2022 02:42:32 -0700 (PDT) Received: from [10.163.34.65] (unknown [10.163.34.65]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B61933F73D; Wed, 16 Mar 2022 02:42:30 -0700 (PDT) Message-ID: Date: Wed, 16 Mar 2022 15:12:35 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH] mm: add access/dirty bit on numa page fault Content-Language: en-US To: maobibo , 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: Anshuman Khandual In-Reply-To: <3756661c-d710-7bf6-76ab-39ac44f8e8b3@loongson.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 ?