Commit d87cda50 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Move rcu_print_task_exp_stall() to tree_exp.h 



Because expedited CPU stall warnings are contained within the
kernel/rcu/tree_exp.h file, rcu_print_task_exp_stall() should live
there too.  This commit carries out the required code motion.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent 21d0d79a

kernel/rcu/tree_exp.h

+32 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/lockdep.h>



static void rcu_exp_handler(void *unused);

static int rcu_print_task_exp_stall(struct rcu_node *rnp);



/*

 * Record the start of an expedited grace period.
@@ -670,6 +671,27 @@ static void sync_sched_exp_online_cleanup(int cpu) 
{

}



/*

 * Scan the current list of tasks blocked within RCU read-side critical

 * sections, printing out the tid of each that is blocking the current

 * expedited grace period.

 */

static int rcu_print_task_exp_stall(struct rcu_node *rnp)

{

	struct task_struct *t;

	int ndetected = 0;



	if (!rnp->exp_tasks)

		return 0;

	t = list_entry(rnp->exp_tasks->prev,

		       struct task_struct, rcu_node_entry);

	list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {

		pr_cont(" P%d", t->pid);

		ndetected++;

	}

	return ndetected;

}



#else /* #ifdef CONFIG_PREEMPT_RCU */



/* Invoked on each online non-idle CPU for expedited quiescent state. */
@@ -709,6 +731,16 @@ static void sync_sched_exp_online_cleanup(int cpu) 
	WARN_ON_ONCE(ret);

}



/*

 * Because preemptible RCU does not exist, we never have to check for

 * tasks blocked within RCU read-side critical sections that are

 * blocking the current expedited grace period.

 */

static int rcu_print_task_exp_stall(struct rcu_node *rnp)

{

	return 0;

}



#endif /* #else #ifdef CONFIG_PREEMPT_RCU */



/**

kernel/rcu/tree_plugin.h

+0 −31
Original line number Diff line number Diff line
@@ -642,27 +642,6 @@ static void rcu_read_unlock_special(struct task_struct *t) 
	rcu_preempt_deferred_qs_irqrestore(t, flags);

}



/*

 * Scan the current list of tasks blocked within RCU read-side critical

 * sections, printing out the tid of each that is blocking the current

 * expedited grace period.

 */

static int rcu_print_task_exp_stall(struct rcu_node *rnp)

{

	struct task_struct *t;

	int ndetected = 0;



	if (!rnp->exp_tasks)

		return 0;

	t = list_entry(rnp->exp_tasks->prev,

		       struct task_struct, rcu_node_entry);

	list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {

		pr_cont(" P%d", t->pid);

		ndetected++;

	}

	return ndetected;

}



/*

 * Check that the list of blocked tasks for the newly completed grace

 * period is in fact empty.  It is a serious bug to complete a grace
@@ -906,16 +885,6 @@ static bool rcu_preempt_need_deferred_qs(struct task_struct *t) 
}

static void rcu_preempt_deferred_qs(struct task_struct *t) { }



/*

 * Because preemptible RCU does not exist, we never have to check for

 * tasks blocked within RCU read-side critical sections that are

 * blocking the current expedited grace period.

 */

static int rcu_print_task_exp_stall(struct rcu_node *rnp)

{

	return 0;

}



/*

 * Because there is no preemptible RCU, there can be no readers blocked,

 * so there is no need to check for blocked tasks.  So check only for