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 10F3AC46CA1 for ; Mon, 18 Sep 2023 07:18:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A69B06B025F; Mon, 18 Sep 2023 03:18:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F4006B0260; Mon, 18 Sep 2023 03:18:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8BB6F6B0261; Mon, 18 Sep 2023 03:18:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 7AFD66B025F for ; Mon, 18 Sep 2023 03:18:14 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 56ED016038F for ; Mon, 18 Sep 2023 07:18:14 +0000 (UTC) X-FDA: 81248864508.13.C1D675A Received: from out-227.mta1.migadu.com (out-227.mta1.migadu.com [95.215.58.227]) by imf28.hostedemail.com (Postfix) with ESMTP id 9FFEAC0002 for ; Mon, 18 Sep 2023 07:18:12 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=xDx23adU; spf=pass (imf28.hostedemail.com: domain of muchun.song@linux.dev designates 95.215.58.227 as permitted sender) smtp.mailfrom=muchun.song@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695021492; 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:dkim-signature; bh=UfSW8jEm1VNQCD8pQwx0JLLdK+5bGgzdvIUujZD6iqI=; b=uvO+SQcV6KYu8SsFwNuoEqIz6YO8IaYXLPhtq8WSufcIf9VnMVvn6UtsablHiFuX9MbUum ue7BWZwg85B/EGFw2BVXWcoTjeZJK2yuxI+Qd8BiT2ZfadAIXtpX+WkrSv3NZT/4nLJdjI xIbRdL/a8QvOXLZ/JN444BK0XOvPKgE= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695021492; a=rsa-sha256; cv=none; b=kPfka4H7ue6LSTRUFYYUJsewbAnL4v9CUAweaQhvEvAIESuMKgIUxnC7z2KGw1g6gtekU+ E6vgNL1jhcNNPVK2ZjUnBoo9ReCF0bYEDsl9LQ0BAFB60CbtmRuMacnQzLaZfDCeoG+eUJ gLcLxeK58NqT5imjoD8eW7oqAXwj5hE= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=xDx23adU; spf=pass (imf28.hostedemail.com: domain of muchun.song@linux.dev designates 95.215.58.227 as permitted sender) smtp.mailfrom=muchun.song@linux.dev; dmarc=pass (policy=none) header.from=linux.dev Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1695021491; h=from:from: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=UfSW8jEm1VNQCD8pQwx0JLLdK+5bGgzdvIUujZD6iqI=; b=xDx23adUJq5H0ND0LkfTuGurXvDHBHI9PV6YTxEa06Kb/6sHlZwz4m5BsD3c4tuG6sM570 9GThhUfP+ZzNSF0u16ob3x2ewc+WNyoSAvPezwqg2vBX12Z20FOSqLxL1MGhrmKuQEjten OdYGLFAeEXGjk1pQgP8j79Nabvccp2Y= Mime-Version: 1.0 Subject: Re: [PATCH v6 44/45] mm: shrinker: hold write lock to reparent shrinker nr_deferred X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: <20230911094444.68966-45-zhengqi.arch@bytedance.com> Date: Mon, 18 Sep 2023 15:17:38 +0800 Cc: Andrew Morton , david@fromorbit.com, tkhai@ya.ru, Vlastimil Babka , Roman Gushchin , djwong@kernel.org, brauner@kernel.org, paulmck@kernel.org, tytso@mit.edu, steven.price@arm.com, cel@kernel.org, senozhatsky@chromium.org, yujie.liu@intel.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: <807B2489-9F74-4B35-925D-B379E47E75AD@linux.dev> References: <20230911094444.68966-1-zhengqi.arch@bytedance.com> <20230911094444.68966-45-zhengqi.arch@bytedance.com> To: Qi Zheng X-Migadu-Flow: FLOW_OUT X-Stat-Signature: mbxf968nmjuqc64fyyhnnkpib1iomcta X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 9FFEAC0002 X-Rspam-User: X-HE-Tag: 1695021492-562067 X-HE-Meta: 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 5LwM2R8u jBNiBzkiP8l2pvXVKW3MX4x75EMnwkRbEvESVKpmU6sCvsW0hKx9k9i4WS8ykmUvkYZD8HHNmr8wz6oqNCVs0it8USUP/GsrJBOpQOfixnEgl0FamI4I+QaSa8RISpz954EzkULHEZfGd6GcbXhfbnR6ghn6PV1YrxE7arxEEYEhDk0F4Z+DuoHsL0M2wHIpVVaM2dMQJWgHr0jQCCH0o5qWBXH7s8oVCgTiIADpB+JCsYFlQiJaGtlwIXNYYmtWfAcbk7q38N/MZdP62cBKi7gbj5aetdDigxMzl 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 Sep 11, 2023, at 17:44, Qi Zheng wrote: > > For now, reparent_shrinker_deferred() is the only holder of read lock of > shrinker_rwsem. And it already holds the global cgroup_mutex, so it will > not be called in parallel. > > Therefore, in order to convert shrinker_rwsem to shrinker_mutex later, > here we change to hold the write lock of shrinker_rwsem to reparent. > > Signed-off-by: Qi Zheng Reviewed-by: Muchun Song Thanks.