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Fri, 11 Sep 2026 07:58:50 +0000 X-Mizu-Trace-ID: 6843b9e642dbf692 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, 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 02/15] mm/oom_kill: convert process/thread iterators to for_each_*_rculock Date: Fri, 11 Sep 2026 15:57:47 +0800 Message-Id: <20260911075800.491472-3-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: E8F6AC000B X-Rspam-User: X-Stat-Signature: hq3i5gfte7jerqhjur84wfsq1bm1utyr X-HE-Tag: 1789113531-420465 X-HE-Meta: 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 1jIKbIpn pAU5leoEDTelZsbMk7QCPbDeKzCk7oUbzMWwW44ucEJukYYBxOlhYsJbRMAmwmioInvs6/d6L6jk+giurFSK7ORMkQ7BN9eo7ar765N0I4nvaPPuOGyGQnYNKrQPWLXBb8IxloyveuWeJeVllv8BSP1EnYDN9qZG0sy2Kl78jiqjvFzHyllyBgyScywndCh6e8ZRhQeZPLm59aoOiAcvrxVwqZmIDzFhz87BArYEyyf54qSbGUDDy6kqrKA5MfGBBBkJFuEQIZz1qANLZlHMs0O6Qdao6p488Iy6Ygsn4iPAQK9EondpGhojRSbhlDzYdKzx5Daja6//UKRUMA5hbe4G2HlsoPLmWhco790fxttTc2Ol9W4Cld5uZ0Iinik2wK0OUbrpHqwQANcGsgpjpRoalxxPnh6siJmTuEDub7B8b/S2RlkoiAgVSSmeqDwZVWty9gpcgYHd/tjP+HkK8Pl9vCVkXFpuUup+4XOGyYTplpeQ= 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) --- 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