From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-43.mta1.migadu.com [95.215.58.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BEE0045FFA4 for ; Mon, 21 Sep 2026 09:22:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789982565; cv=none; b=I8pMKCDiN9C6sZiJpPyDyPI2dy/s89fLW81mjyMqfA3qqi2R0kOWzVqoq2cODoS0xhHNFoxT09fzSUS2lWEC3f+9rzeIsK1uQ7K2Xu0CWDZGnHDASyaYT5yUwwTdpTsyEJqgl4TvlvWyTaEodSW4GDpImUf8+gXk27TM9AQdVyY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789982565; c=relaxed/simple; bh=FGT5bYNhb7F30R7KVhWzfpI91BeKfJqsry/WZ5Za0+s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ACFvXygYynrkIDwSFfB+Dy1u8u02BRwT0TGfLkiCvzJoBvJBJijpFvHsrjJw+2KD1Ip4uu6dhNLH3i1ZMQ2A1BDKNT5gCgD0cph0xpUWdodgjPHiwXbRFunpIW2iEJVVKXxQ9Q5eF5n5/gm3AXfPXdB0JlnkOY9vE3k0pUbgI2k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=cbeFATl/; arc=none smtp.client-ip=95.215.58.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="cbeFATl/" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=FGT5bYNhb7F30R7KVhWzfpI91BeKfJqsry/WZ5Za0+s=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789982560; v=1; x=1790587360; b=cbeFATl/S/mO56iCGH+rcO9I9RDaMqRXPfnxr9OtC/n7BpWdSxMIb7F73keo7iHEgeIWKLj7 w5IkbclUpZdkLKPGFHVcCkayQUatur6sUPPjGy1YUvMqirnPoAQwi1F5AWevXbPOkyrxWXxMsgL 0NnzqRhYOJVlNlh/TecAs9B4= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 311c3a7172cefc8c; Mon, 21 Sep 2026 09:22:40 +0000 X-Mizu-Trace-ID: 311c3a7172cefc8c X-Migadu-Flow: FLOW_OUT From: Ye Liu To: Thomas Gleixner , Peter Zijlstra Cc: Ye Liu , Michal Hocko , SJ Park , Lorenzo Stoakes , Oleg Nesterov , akpm@linux-foundation.org, paulmck@kernel.org, mingo@redhat.com, rostedt@goodmis.org, jpoimboe@kernel.org, mic@digikod.net, david@kernel.org, linmiaohe@huawei.com, nao.horiguchi@gmail.com, rafael@kernel.org, gnoack3000@gmail.com, gourry@gourry.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rcu@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, rientjes@google.com, shakeel.butt@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, will@kernel.org, boqun@kernel.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com, josh@joshtriplett.org, urezki@gmail.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, tony.luck@intel.com, reinette.chatre@intel.com, x86@kernel.org, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, pavel@kernel.org, lance.yang@linux.dev, mhiramat@kernel.org, pmladek@suse.com, longman@redhat.com, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang@linux.dev, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com, mark.rutland@arm.com, Dave.Martin@arm.com, james.morse@arm.com, babu.moger@amd.com Subject: [PATCH v4 05/15] cpu/hotplug: convert process iterator to for_each_process_rculock Date: Mon, 21 Sep 2026 17:20:51 +0800 Message-Id: <20260921092101.89285-6-ye.liu@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260921092101.89285-1-ye.liu@linux.dev> References: <20260921092101.89285-1-ye.liu@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ye Liu Replace the manual rcu_read_lock()/rcu_read_unlock() pair combined with for_each_process() loop in kernel/cpu.c with for_each_process_rculock(), which scopes the RCU read lock to the loop body via scoped_guard(rcu). No functional change. Signed-off-by: Ye Liu Acked-by: Michal Hocko Reviewed-by: SJ Park Reviewed-by: Lorenzo Stoakes (ARM) Reviewed-by: Oleg Nesterov --- kernel/cpu.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index b3c8553d7bd6..00638d2abc0f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1254,8 +1254,7 @@ void clear_tasks_mm_cpumask(int cpu) * full-fledged tasklist_lock. */ WARN_ON(cpu_online(cpu)); - rcu_read_lock(); - for_each_process(p) { + for_each_process_rculock(p) { struct task_struct *t; /* @@ -1268,7 +1267,6 @@ void clear_tasks_mm_cpumask(int cpu) arch_clear_mm_cpumask_cpu(cpu, t->mm); task_unlock(t); } - rcu_read_unlock(); } /* Take this CPU down. */ -- 2.25.1