From: Ye Liu <[email protected]> Replace the manual rcu_read_lock()/rcu_read_unlock() pair combined with for_each_process_thread() loop in kernel/hung_task.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 <[email protected]> Acked-by: Michal Hocko <[email protected]> Reviewed-by: SJ Park <[email protected]> Reviewed-by: Lorenzo Stoakes (ARM) <[email protected]> Reviewed-by: Oleg Nesterov <[email protected]> --- Changes in v3: - Split from kernel/ patch in v2 (Peter Zijlstra, Steven Rostedt) Changes in v2: - Rename *_rcu to *_rculock - Rename stale 'unlock:' label to 'out:' in hung_task.c (Günther Noack) kernel/hung_task.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 6fcc94ce4ca9..73a5ad3be9a8 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -315,13 +315,12 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) return; this_round_count = 0; - rcu_read_lock(); - for_each_process_thread(g, t) { + for_each_process_thread_rculock(g, t) { if (!max_count--) - goto unlock; + goto out; if (time_after(jiffies, last_break + HUNG_TASK_LOCK_BREAK)) { if (!rcu_lock_break(g, t)) - goto unlock; + goto out; last_break = jiffies; } @@ -337,9 +336,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) hung_task_info(t, timeout, this_round_count); } } - unlock: - rcu_read_unlock(); - +out: if (!this_round_count) return; -- 2.25.1
