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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1FDEC433EF for ; Fri, 18 Mar 2022 02:17:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0DA388D0002; Thu, 17 Mar 2022 22:17:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 061EB8D0001; Thu, 17 Mar 2022 22:17:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF6FC8D0002; Thu, 17 Mar 2022 22:17:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id CC2B68D0001 for ; Thu, 17 Mar 2022 22:17:42 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 8CE2921445 for ; Fri, 18 Mar 2022 02:17:42 +0000 (UTC) X-FDA: 79255895964.15.849954E Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by imf14.hostedemail.com (Postfix) with ESMTP id A5E65100016 for ; Fri, 18 Mar 2022 02:17:40 +0000 (UTC) Received: from [10.20.42.25] (unknown [10.20.42.25]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9AxeszA6zNic0cLAA--.9260S3; Fri, 18 Mar 2022 10:17:36 +0800 (CST) Subject: Re: [PATCH v2] mm: add access/dirty bit on numa page fault To: Matthew Wilcox Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Anshuman Khandual References: <20220317065033.2635123-1-maobibo@loongson.cn> From: maobibo Message-ID: <2c9ef479-a371-3fec-4d1b-fc833d8bf3d4@loongson.cn> Date: Fri, 18 Mar 2022 10:17:35 +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:AQAAf9AxeszA6zNic0cLAA--.9260S3 X-Coremail-Antispam: 1UD129KBjvdXoWrCryrJr13Cr1rtF17Jr1DKFg_yoWxGFX_uF 4kWasFg34xGrZ7KF1vqw1rWw43GrWrGryUJ34agrnFq345Xwn3Jr4DGrZ5u3WxJw1Sgr13 Wr1FqFy7W3yIgjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbI8YjsxI4VWkKwAYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM2 8CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0 cI8IcVCY1x0267AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I 8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lc7I2V7IY0VAS07AlzVAYIcxG8wCY 02Avz4vE-syl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4 xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1D MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I 0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrJr0_WFyUJwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj xUgg_TUUUUU X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: A5E65100016 X-Stat-Signature: 5i3o6nf8cpgewudddss96n9fbd8646yp Authentication-Results: imf14.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf14.hostedemail.com: domain of maobibo@loongson.cn designates 114.242.206.163 as permitted sender) smtp.mailfrom=maobibo@loongson.cn X-Rspam-User: X-HE-Tag: 1647569860-88235 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000014, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 03/18/2022 09:46 AM, Matthew Wilcox wrote: > On Fri, Mar 18, 2022 at 09:01:32AM +0800, maobibo wrote: >>> Is this a correctness problem, in which case this will need to be >>> backported, or is this a performance problem, in which case can you >>> share some numbers? >> It is only performance issue, and there is no obvious performance >> improvement for general workloads on my hand, but I do not test >> it on microbenchmark. > > ... if there's no performance improvement, why should we apply this > patch? Confused. > It is not obvious from workload view, it actually reduces one tlb miss on platforms without hw page walk.