5.15-stable review patch. If anyone has any objections, please let me know.
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From: Paul E. McKenney paulmck@kernel.org
commit 5c9a9ca44fda41c5e82f50efced5297a9c19760d upstream.
Any idle task corresponding to an offline CPU is in an RCU Tasks Trace quiescent state. This commit causes rcu_tasks_trace_postscan() to ignore idle tasks for offline CPUs, which it can do safely due to CPU-hotplug operations being disabled.
Signed-off-by: Paul E. McKenney paulmck@kernel.org Cc: Neeraj Upadhyay quic_neeraju@quicinc.com Cc: Eric Dumazet edumazet@google.com Cc: Alexei Starovoitov ast@kernel.org Cc: Andrii Nakryiko andrii@kernel.org Cc: Martin KaFai Lau kafai@fb.com Cc: KP Singh kpsingh@kernel.org Signed-off-by: Krister Johansen kjlx@templeofstupid.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/rcu/tasks.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 0e50ec9ded86e..0a83d0ce46d78 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1090,7 +1090,7 @@ static void rcu_tasks_trace_postscan(struct list_head *hop) { int cpu;
- for_each_possible_cpu(cpu) + for_each_online_cpu(cpu) rcu_tasks_trace_pertask(idle_task(cpu), hop);
// Re-enable CPU hotplug now that the tasklist scan has completed.