Heavy networking load can cause a CPU to execute continuously and
indefinitely within ksoftirqd, in which case there will be no voluntary
task switches and thus no RCU-tasks quiescent states. This commit
therefore causes the exiting rcu_softirq_qs() to provide an RCU-tasks
quiescent state.
This of course means that __do_softirq() and its callers cannot be
invoked from within a tracing trampoline.
Reported-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Tested-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/rcu/tree.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8e78b2430c16..f4daa4e60b14 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -242,6 +242,7 @@ void rcu_softirq_qs(void)
{
rcu_qs();
rcu_preempt_deferred_qs(current);
+ rcu_tasks_qs(current, false);
}
/*
--
2.31.1.189.g2e36527f23
