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Mon, 21 Sep 2026 09:21:53 +0000 X-Mizu-Trace-ID: 63f02883ed771dab X-Migadu-Flow: FLOW_OUT From: Ye Liu To: Michal Hocko , Andrew Morton Cc: Ye Liu , SJ Park , Gregory Price , Lorenzo Stoakes , 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, 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 02/15] mm/oom_kill: convert process/thread iterators to for_each_*_rculock Date: Mon, 21 Sep 2026 17:20:48 +0800 Message-Id: <20260921092101.89285-3-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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Stat-Signature: c9o8yhxf7o3pxffgk9r1oxrse7k3fr7t X-Rspamd-Queue-Id: D7285C0002 X-Rspamd-Server: rspam07 X-HE-Tag: 1789982514-505610 X-HE-Meta: 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 JYkpWyIa jA116JfWa6h3VuSnFgzU8+8VeO7rXAO2VceLwb8E+O1GcmGTiG+tCZWiKssR1MwKNwtbiAc1gzZLR+WjFdanl9spb6pYZLGJMomz10OjxGZqud1Hd/TmVFrT3hql/O6ZGUwfOrDQ7Vbl30L0ZGnQvcBt+g3VcZzbdKKQXoR/fkd4WNghfwFTFBbhGypyHiWAXS+1qvhdS7dRd0ARe+NBd1t0VOUcA++bsQm47Oc7oGVecqY8G+vMLvJxiU0qWWTwU+kFexJi4k2b1UXDkYxAaCMW3BnzrIX7rIeRVWLmuc++s+jg9w9/tb3XnCU2pRfoSlvBjbW5Nfa0zuyQ8DqUbIwUfdB6ODGt5BbZl2aSxnfJI3XnWz90Ns0JBCFYpfxrd+8wCkuPVzrSNnPkjDoRUErHFWVG9CJUemEYCwU9My5tkBGoK/OeH/vmNsCjE7klVbehCk5ANMGbxf4x7VUc6qCVyR3R5y0P/8tko4J1IUkoyxIQ= 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 Reviewed-by: Gregory Price (Meta) Reviewed-by: Lorenzo Stoakes (ARM) --- 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