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Mon, 07 Sep 2026 08:14:16 +0000 X-Mizu-Trace-ID: be9bc340ab630053 X-Migadu-Flow: FLOW_OUT From: Ye Liu To: Michal Hocko , Andrew Morton Cc: Ye Liu , SJ Park , peterz@infradead.org, paulmck@kernel.org, mingo@redhat.com, rostedt@goodmis.org, jpoimboe@kernel.org, mic@digikod.net, oleg@redhat.com, tglx@kernel.org, david@kernel.org, linmiaohe@huawei.com, nao.horiguchi@gmail.com, rafael@kernel.org, gnoack3000@gmail.com, ljs@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, 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 v2 2/8] mm/oom_kill: convert process/thread iterators to for_each_*_rculock Date: Mon, 7 Sep 2026 16:13:28 +0800 Message-Id: <20260907081334.1152889-3-ye.liu@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260907081334.1152889-1-ye.liu@linux.dev> References: <20260907081334.1152889-1-ye.liu@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: zrua4u7f5jdyricqhia6hiqzufiomr96 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 644E61A0009 X-Rspam-User: X-HE-Tag: 1788768858-478302 X-HE-Meta: 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 g7uUa7sG iMEsEGShsVTvQQPnWBo8zkQYXHkeOdj4hiaY/jtEF5xf1nKRaPa9D7whPsL70iATzsyBUy2SYye0HWZG9DlB70P/TOYtc0zT0ET8pcpn8VwD3gMtBTfiixFlbUJDH5pmO16eBnoDcX9d6axLr8W5NgE0TXY88FTSa8eASbYfEQoKK8pFV4SCuw/JfkMBtFjB8aJe3zlUNwBfFNIhYxOcHUBE2+GMqI4VJ8Qt06DE0+XYdlAqz5x1hXTaZ+N/VfEpN2tuFNgisXjDz8bZNf2pvD+GTgtjApr3+mGRgWTXbnQx/WhT5kuRJB/CbiBhEHnzDQ/MmtHDfh2/O8gWltWL37MVENnUMujVGj/zogFsFaC0UMriG6XL0cYysDKE/do4lu772EgCvC2Cj5NADfRADY/R/QY6hGY0LSMEvC3WfGp3f84/13eEwYcXb4g== 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() pairs wrapping for_each_process()/for_each_thread() loops with for_each_process_rculock() and for_each_thread_rculock(), which scope 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 --- Changes in v2: - Rename *_rcu to *_rculock mm/oom_kill.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 5f372f6e26fa..ef2e1c423c1d 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -94,8 +94,7 @@ static bool oom_cpuset_eligible(struct task_struct *start, bool ret = false; const nodemask_t *mask = oc->nodemask; - rcu_read_lock(); - for_each_thread(start, tsk) { + for_each_thread_rculock(start, tsk) { if (mask) { /* * If this is a mempolicy constrained oom, tsk's @@ -114,7 +113,6 @@ static bool oom_cpuset_eligible(struct task_struct *start, if (ret) break; } - rcu_read_unlock(); return ret; } @@ -368,11 +366,9 @@ static void select_bad_process(struct oom_control *oc) else { struct task_struct *p; - rcu_read_lock(); - for_each_process(p) + for_each_process_rculock(p) if (oom_evaluate_task(p, oc)) break; - rcu_read_unlock(); } } @@ -430,14 +426,12 @@ static void dump_tasks(struct oom_control *oc) struct task_struct *p; int i = 0; - rcu_read_lock(); - for_each_process(p) { + for_each_process_rculock(p) { /* Avoid potential softlockup warning */ if ((++i & 1023) == 0) touch_softlockup_watchdog(); dump_task(p, oc); } - rcu_read_unlock(); } } @@ -894,8 +888,7 @@ static bool task_will_free_mem(struct task_struct *task) * are dying as well to make sure that a) nobody pins its mm and * b) the task is also reapable by the oom reaper. */ - rcu_read_lock(); - for_each_process(p) { + for_each_process_rculock(p) { if (!process_shares_mm(p, mm)) continue; if (same_thread_group(task, p)) @@ -904,7 +897,6 @@ static bool task_will_free_mem(struct task_struct *task) if (!ret) break; } - rcu_read_unlock(); return ret; } @@ -960,8 +952,7 @@ static void __oom_kill_process(struct task_struct *victim, const char *message) * That thread will now get access to memory reserves since it has a * pending fatal signal. */ - rcu_read_lock(); - for_each_process(p) { + for_each_process_rculock(p) { if (!process_shares_mm(p, mm)) continue; if (same_thread_group(p, victim)) @@ -982,7 +973,6 @@ static void __oom_kill_process(struct task_struct *victim, const char *message) continue; do_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_TGID); } - rcu_read_unlock(); if (can_oom_reap) queue_oom_reaper(victim); -- 2.25.1