Commit 2488a5e6 authored Oct 15, 2019 by Lai Jiangshan Committed by Paul E. McKenney Jan 24, 2020

rcu: Fix tracepoint tracking RCU CPU kthread utilization



In the call to trace_rcu_utilization() at the start of the loop in
rcu_cpu_kthread(), "rcu_wait" is incorrect, plus this trace event needs
to be hoisted above the loop to balance with either the "rcu_wait" or
"rcu_yield", depending on how the loop exits.  This commit therefore
makes these changes.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

parent 822175e7

kernel/rcu/tree.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2474,8 +2474,8 @@ static void rcu_cpu_kthread(unsigned int cpu)
		char work, *workp = this_cpu_ptr(&rcu_data.rcu_cpu_has_work);
		int spincnt;

		trace_rcu_utilization(TPS("Start CPU kthread@rcu_run"));
		for (spincnt = 0; spincnt < 10; spincnt++) {
		trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
		local_bh_disable();
		*statusp = RCU_KTHREAD_RUNNING;
		local_irq_disable();

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