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 0E9AEC004D4 for ; Wed, 18 Jan 2023 06:27:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 39F826B0071; Wed, 18 Jan 2023 01:27:02 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 34F646B0072; Wed, 18 Jan 2023 01:27:02 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 217126B0074; Wed, 18 Jan 2023 01:27:02 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 0EEFE6B0071 for ; Wed, 18 Jan 2023 01:27:02 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id D48AAA0BC5 for ; Wed, 18 Jan 2023 06:27:01 +0000 (UTC) X-FDA: 80366937042.14.AAE445A Received: from mail3-166.sinamail.sina.com.cn (mail3-166.sinamail.sina.com.cn [202.108.3.166]) by imf16.hostedemail.com (Postfix) with ESMTP id 97DA0180005 for ; Wed, 18 Jan 2023 06:26:56 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of hdanton@sina.com designates 202.108.3.166 as permitted sender) smtp.mailfrom=hdanton@sina.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674023220; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=o2ZUy/ESSts/bUq7ajaHvD0Bg3CrHL/dZgUtx1b8T80=; b=Ha5JqT2b5qGmdXV1KlDma0f5rdNFv5j3V9qRvRPrP7zbWiaSWeibnuQcGHBZGlZv5GA3Ku DMRoDjHELxHIcFicQGaUDb061uTNQjhdlJz1PxWD+EZ91O/dTLG6DGnBpeRKSMLmwgY5ha yBr9CIIb/8TC+VW2oxmCHV2VEF74pMg= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of hdanton@sina.com designates 202.108.3.166 as permitted sender) smtp.mailfrom=hdanton@sina.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674023220; a=rsa-sha256; cv=none; b=SqU6sZps1m7Pcj667Gq7dnQhQpxYJc9LdDdFfev2cDMaxL4hLjbvydeZMECyuP6G9U3xqW HtR9WwAMT7EAoMGrBPuoe/HS1HA7/i2IsTibLI+IpCDCB+Wf2T9v+72x7ye6lWKEih4/2/ xjik+HjOM94QYxscxTcdDtx8BJlmrWw= Received: from unknown (HELO localhost.localdomain)([114.249.61.130]) by sina.com (172.16.97.23) with ESMTP id 63C7906C0001AFA8; Wed, 18 Jan 2023 14:23:42 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 9426554919561 From: Hillf Danton To: Matthew Wilcox Cc: Suren Baghdasaryan , Hillf Danton , vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, peterz@infradead.org, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 41/41] mm: replace rw_semaphore with atomic_t in vma_lock Date: Wed, 18 Jan 2023 14:26:39 +0800 Message-Id: <20230118062639.2839-1-hdanton@sina.com> In-Reply-To: References: <20230109205336.3665937-42-surenb@google.com> <20230116140649.2012-1-hdanton@sina.com> <20230117031632.2321-1-hdanton@sina.com> <20230117083355.2374-1-hdanton@sina.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 97DA0180005 X-Stat-Signature: z1ohsnd9ztk38eug88xggfyst3hteabk X-Rspam-User: X-HE-Tag: 1674023216-218737 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jan 17, 2023 at 10:27 AM Matthew Wilcox wrote: > > The cpu_relax() is exactly the wrong thing to do here. See this thread: > https://lore.kernel.org/linux-fsdevel/20230113184447.1707316-1-mjguzik@gmail.com/ If you are right, feel free to go and remove every cpu_relax() under the kernel/locking directory.