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 5A5EFC43334 for ; Sat, 18 Jun 2022 02:49:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CEFDF6B0071; Fri, 17 Jun 2022 22:49:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C9F116B0072; Fri, 17 Jun 2022 22:49:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B67AF6B0073; Fri, 17 Jun 2022 22:49:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id A76786B0071 for ; Fri, 17 Jun 2022 22:49:48 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 6F69117F3 for ; Sat, 18 Jun 2022 02:49:48 +0000 (UTC) X-FDA: 79589826456.05.03CA578 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf25.hostedemail.com (Postfix) with ESMTP id B6F55A008E for ; Sat, 18 Jun 2022 02:49:47 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4LQ0j12rG4zjXyX; Sat, 18 Jun 2022 10:48:37 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 18 Jun 2022 10:49:44 +0800 Subject: Re: [PATCH v4 1/4] mm: reduce the rcu lock duration To: Andrew Morton CC: "Eric W. Biederman" , Ying Huang , , , , , , , , , , , References: <20220530113016.16663-1-linmiaohe@huawei.com> <20220530113016.16663-2-linmiaohe@huawei.com> <87bkvdfzvm.fsf@email.froward.int.ebiederm.org> <87y1yga1r2.fsf@email.froward.int.ebiederm.org> <87ilph90dx.fsf@email.froward.int.ebiederm.org> <20220617172316.de2d41877e86be344052b9f5@linux-foundation.org> From: Miaohe Lin Message-ID: <5abc85bc-fec7-afbf-4ec4-90c1385195d2@huawei.com> Date: Sat, 18 Jun 2022 10:49:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220617172316.de2d41877e86be344052b9f5@linux-foundation.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655520588; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IIdPx4fTsXwiRfZjrpOlVAAwZvjGNMCsCI5jhfwA7VU=; b=v2LomIxSyVQttYEAdtwUPIaTNwBUB4SPfmzIDIcG8GqjNSLMxhtiFtOJNK0kjkp1VUB+MT Qrkf/1D/Ec4zPHUe/TVsNOVAlbai/fVom2YrMOV88rSX3lV9wMgKcN26GhvLG9h1gKbkUz lr92GjkDm+MqCgfLSMCo+SMeZg7P+WM= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=none; spf=pass (imf25.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655520588; a=rsa-sha256; cv=none; b=3BLr/Qe/ZkVTqNWjGZEGoTwiRGaTSoDqv554jg6niQm2gGXhbUeLD97aaB/ToY4UEjvEZ4 M9CJX8KLzR0K4OIgZbxR9EjtYugOuYJgnSGxz20XFyBc9d9LFR9FPdpqY2UZTvPKTHBLkA hEUxXvKpBBYu83/CbgimmQZJx5yyzuc= X-Stat-Signature: 1j7i5qac7wud7gedcinfr95uf67r8wo9 X-Rspamd-Queue-Id: B6F55A008E X-Rspamd-Server: rspam11 X-Rspam-User: Authentication-Results: imf25.hostedemail.com; dkim=none; spf=pass (imf25.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-HE-Tag: 1655520587-976485 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2022/6/18 8:23, Andrew Morton wrote: > On Tue, 7 Jun 2022 17:19:53 +0800 Miaohe Lin wrote: > >>> >>> >>> If the checks are not made to guarantee they are all checking against >>> the same mm, the code needs a comment to say that there is a tiny race. >>> The comment should say we don't care about the tiny race because >>> the worst that can happen is that a page is migrated to a different >>> numa node. And so we don't care. >>> >>> >> >> I tend to do this one. To make sure, is the below code change what you suggest? > > Eric went quiet. > > As I understand it, any changes arising from this discussion can be > done as a followup patch. So I'm planning on moving this 4-patch > series into the non-rebasing mm-stable branch late next week. I will send a followup patch when discussion is done. Thanks. > > > . >