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Fri, 11 Sep 2026 07:59:30 +0000 X-Mizu-Trace-ID: 31e1e1833329852b X-Migadu-Flow: FLOW_OUT From: Ye Liu To: Thomas Gleixner , Peter Zijlstra Cc: Ye Liu , Michal Hocko , SJ Park , Lorenzo Stoakes , Oleg Nesterov , paulmck@kernel.org, mingo@redhat.com, rostedt@goodmis.org, jpoimboe@kernel.org, mic@digikod.net, akpm@linux-foundation.org, david@kernel.org, linmiaohe@huawei.com, nao.horiguchi@gmail.com, rafael@kernel.org, gnoack3000@gmail.com, gourry@gourry.net, 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, 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 Subject: [PATCH v3 05/15] cpu/hotplug: convert thread iterator to for_each_thread_rculock Date: Fri, 11 Sep 2026 15:57:50 +0800 Message-Id: <20260911075800.491472-6-ye.liu@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260911075800.491472-1-ye.liu@linux.dev> References: <20260911075800.491472-1-ye.liu@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: D9DC540004 X-Rspam-User: X-Stat-Signature: bepugipprhmzh7jsuc4pseejqnmurbig X-HE-Tag: 1789113572-260998 X-HE-Meta: U2FsdGVkX19W9i6QLhB+eL+W2pu26mS4EQTru7IpkR617rl7VQa5P4DYjHXpyZQ+gfswqPj9cC5/BcJD2dm1/on3FhaRuEDfSlDrVE1SxFDWIJhCsdohHAPVkzy6HeUa40Dg9pYVtkG5Ibsw5MhdKDK9FwvRcpQBnqPlC5enxygDaX8Fcg7hyHkpKyQ+jray3XutcdsAhDdD/cpzahElCbuS9yj4mv+BS+/wgt6cGqzXn0oubRye2bQZiwB0VW5kBBACn8VN5CVFtZqRUIW+z6g/rZyZEbnPS6bt2KsnoEhDzxoicCBhOlRg7neGhOhZjPYKXjoHoSlkcEsSeOxDMeCD8JJrd1CE2EjXxr2XihKORNto6BmcMV7qI9/ThhWX3HkX6bXjCFASOTMwIDRFpnlW3aMohI2TiOZ4VBtFfNdRzK++jA5C1EnVLpfMrbsYcXFZLOoro6HhvM/YhPRY1QAZNdhhIHUCRhBwm7/C/IE5ax1F/fum0FgRlgUiXH1V5Vs76+FJw5LOPF/KMgeqguLLliudFjkcDzVE1PFzhxvOzkWpOqC0qcpXjjojzcRQHqk+WZksq5+dBAHjEgHRci52GdQt8zoFRcj7nqLcskYMkjyMoJIMeSM0bHWWx2q+NTS67MTQuRjZzk4D9BUNHsv6x40ZdzKgNl+U4bpOaXSksCczKjUNmskREGoPS/0E94Di7oyeuONgLPlviJHkurP5nf8g3z2asaq8QngRD7SbYq77Vsz4rUsZ0yWjnLltJI+idtxMcfz6XimQX/Msruq89YDGbJKfhWZFJhwxa3gV2l5H1JNU58hzu7yHj2kVW/ciJmd8cJ98zkDfElWiDKO+GEVO8PpEJrT5L3pFjSOlaA+tP5MolUA2sTivN+kxbhWac4hXH1MLalJaVE7l7nk5eyCyj1Go6+sri1POXwIkSxVsrbsItYOwL3/6Yb5ElVIhrwL+nnO9A5qG25I nvR+YO/Y GotMd8MeacM9mj7A90Xb40v/Q46CUfuZD62Vqw/pFlZOo2LylbhdxIzjGTAYC7iQgvebtZvawH5ehbtbzzb4j8WKKCSiT2prG9MDz08PS+CEfbKa/wK67uCBXl0g0hxqGQ+jNh5Lk4uunsdiQJ9FZASfwInFg04tggmsq60ShwU7srrf8xXmEbXlcSjdeeF5fCGz20Ra5Ipjoqaiwk9wDdtP/liMLsWf6XajDYMmdR4fn6oiJ/N7+PaJw8c+VmxFRqsZx4N3ZB9ICcdXtJLduIpAaHfNGABM13AX3DE1ou1vlAktLZCku9pjgykwRlO078SO6Zn1h4OoQF7hPOj72ew3HMKukMtA0A/T+XZ4R0t3HC9M5FiqeEUNy1HVSx1kv5yj9zwZhGjmo3RjHQpyuVllOtZ8sJh497+Ipej4mp97r9L3qFtI+g0NZNLD9zBg1NTI94Lcd67XoiJo= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ye Liu Replace the manual rcu_read_lock()/rcu_read_unlock() pair combined with for_each_thread() loop in kernel/cpu.c with for_each_thread_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 --- Changes in v3: - Split from kernel/ patch in v2 (Peter Zijlstra, Steven Rostedt) Changes in v2: - Rename *_rcu to *_rculock 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