Commit 6ae4c30f authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Uladzislau Rezki (Sony)
Browse files

rcu: Replace open-coded rcu_exp_need_qs() from rcu_exp_handler() with call 



Currently, the preemptible implementation of rcu_exp_handler()
almost open-codes rcu_exp_need_qs().  A call to that function would be
shorter and would improve expediting in cases where rcu_exp_handler()
interrupted a preemption-disabled or bh-disabled region of code.
This commit therefore moves rcu_exp_need_qs() out of the non-preemptible
leg of the enclosing #ifdef and replaces the open coding in preemptible
rcu_exp_handler() with a call to rcu_exp_need_qs().

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
parent e2bd1682

kernel/rcu/tree_exp.h

+13 −16
Original line number Diff line number Diff line
@@ -718,6 +718,16 @@ static void rcu_exp_sel_wait_wake(unsigned long s) 
	rcu_exp_wait_wake(s);

}



/* Request an expedited quiescent state. */

static void rcu_exp_need_qs(void)

{

	__this_cpu_write(rcu_data.cpu_no_qs.b.exp, true);

	/* Store .exp before .rcu_urgent_qs. */

	smp_store_release(this_cpu_ptr(&rcu_data.rcu_urgent_qs), true);

	set_tsk_need_resched(current);

	set_preempt_need_resched();

}



#ifdef CONFIG_PREEMPT_RCU



/*
@@ -742,13 +752,10 @@ static void rcu_exp_handler(void *unused) 
	 */

	if (!depth) {

		if (!(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK)) ||

		    rcu_is_cpu_rrupt_from_idle()) {

		    rcu_is_cpu_rrupt_from_idle())

			rcu_report_exp_rdp(rdp);

		} else {

			WRITE_ONCE(rdp->cpu_no_qs.b.exp, true);

			set_tsk_need_resched(t);

			set_preempt_need_resched();

		}

		else

			rcu_exp_need_qs();

		return;

	}
@@ -841,16 +848,6 @@ static void rcu_exp_print_detail_task_stall_rnp(struct rcu_node *rnp) 


#else /* #ifdef CONFIG_PREEMPT_RCU */



/* Request an expedited quiescent state. */

static void rcu_exp_need_qs(void)

{

	__this_cpu_write(rcu_data.cpu_no_qs.b.exp, true);

	/* Store .exp before .rcu_urgent_qs. */

	smp_store_release(this_cpu_ptr(&rcu_data.rcu_urgent_qs), true);

	set_tsk_need_resched(current);

	set_preempt_need_resched();

}



/* Invoked on each online non-idle CPU for expedited quiescent state. */

static void rcu_exp_handler(void *unused)

{