[PATCH v4 09/15] rcu: convert process/thread iterator to for_each_process_thread_rculock
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COLD19d
REVIEWED: 4 (4M)
From: Ye Liu <hidden>
Date: 2026-09-21 09:23:44
Also in:
linux-fsdevel, linux-mm, linux-pm, linux-trace-kernel, lkml, rcu
Subsystem:
read-copy update (rcu), the rest · Maintainers:
"Paul E. McKenney", Frederic Weisbecker, Neeraj Upadhyay, Joel Fernandes, Josh Triplett, Boqun Feng, Uladzislau Rezki, Linus Torvalds
Status: Reviewed.
Revision v4 (2 revisions archived); 4 review trailers.
Revisions (2)
- v3
- v4 current [diff against previous]
From: Ye Liu <liuye@kylinos.cn>
Replace the manual rcu_read_lock()/rcu_read_unlock() pair combined
with for_each_process_thread() loop in kernel/rcu/update.c with
for_each_process_thread_rculock(), which scopes 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>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
---
kernel/rcu/update.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 2a778b8ab4ad..d8e0b5896db9 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c@@ -548,15 +548,13 @@ void synchronize_rcu_trivial_preempt(void) struct task_struct *t; smp_mb(); // Order prior accesses before grace-period start. - rcu_read_lock(); // Protect task list. - for_each_process_thread(g, t) { + for_each_process_thread_rculock(g, t) { if (t == current) continue; // Don't deadlock on ourselves! // Order later rcu_read_lock() on other tasks after QS. while (smp_load_acquire(&t->rcu_trivial_preempt_nesting)) continue; } - rcu_read_unlock(); } EXPORT_SYMBOL_GPL(synchronize_rcu_trivial_preempt); #endif // #if IS_ENABLED(CONFIG_TRIVIAL_PREEMPT_RCU)
--
2.25.1