[PATCH v2 2/8] mm/oom_kill: convert process/thread iterators to for_each_*_rculock
From: Ye Liu <hidden>
Date: 2026-09-07 08:14:19
Also in:
linux-fsdevel, linux-mm, linux-pm, linux-security-module, lkml, rcu
Subsystem:
memory management, memory management - oom killer, the rest · Maintainers:
Andrew Morton, Michal Hocko, Linus Torvalds
From: Ye Liu <liuye@kylinos.cn> 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 <liuye@kylinos.cn> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: SJ Park <sj@kernel.org> --- 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