Commit c035280f authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu/nocb: Remove obsolete nocb_q_count and nocb_q_count_lazy fields 



This commit removes the obsolete nocb_q_count and nocb_q_count_lazy
fields, also removing rcu_get_n_cbs_nocb_cpu(), adjusting
rcu_get_n_cbs_cpu(), and making rcutree_migrate_callbacks() once again
disable the ->cblist fields of offline CPUs.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent e7f4c5b3

kernel/rcu/tree.c

+3 −3
Original line number Diff line number Diff line
@@ -210,10 +210,9 @@ static long rcu_get_n_cbs_cpu(int cpu) 
{

	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);



	if (rcu_segcblist_is_enabled(&rdp->cblist) &&

	    !rcu_segcblist_is_offloaded(&rdp->cblist)) /* Online normal CPU? */

	if (rcu_segcblist_is_enabled(&rdp->cblist))

		return rcu_segcblist_n_cbs(&rdp->cblist);

	return rcu_get_n_cbs_nocb_cpu(rdp); /* Works for offline, too. */

	return 0;

}



void rcu_softirq_qs(void)
@@ -3181,6 +3180,7 @@ void rcutree_migrate_callbacks(int cpu) 
	needwake = rcu_advance_cbs(my_rnp, rdp) ||

		   rcu_advance_cbs(my_rnp, my_rdp);

	rcu_segcblist_merge(&my_rdp->cblist, &rdp->cblist);

	rcu_segcblist_disable(&rdp->cblist);

	WARN_ON_ONCE(rcu_segcblist_empty(&my_rdp->cblist) !=

		     !rcu_segcblist_n_cbs(&my_rdp->cblist));

	if (rcu_segcblist_is_offloaded(&my_rdp->cblist)) {

kernel/rcu/tree.h

+0 −3
Original line number Diff line number Diff line
@@ -194,8 +194,6 @@ struct rcu_data { 


	/* 5) Callback offloading. */

#ifdef CONFIG_RCU_NOCB_CPU

	atomic_long_t nocb_q_count;	/* # CBs waiting for nocb */

	atomic_long_t nocb_q_count_lazy; /*  invocation (all stages). */

	struct rcu_head *nocb_cb_head;	/* CBs ready to invoke. */

	struct rcu_head **nocb_cb_tail;

	struct swait_queue_head nocb_cb_wq; /* For nocb kthreads to sleep on. */
@@ -437,7 +435,6 @@ static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp, 
#ifdef CONFIG_RCU_NOCB_CPU

static void __init rcu_organize_nocb_kthreads(void);

#endif /* #ifdef CONFIG_RCU_NOCB_CPU */

static unsigned long rcu_get_n_cbs_nocb_cpu(struct rcu_data *rdp);

static void rcu_bind_gp_kthread(void);

static bool rcu_nohz_full_cpu(void);

static void rcu_dynticks_task_enter(void);

kernel/rcu/tree_plugin.h

+0 −14
Original line number Diff line number Diff line
@@ -2040,15 +2040,6 @@ void rcu_bind_current_to_nocb(void) 
}

EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb);



/*

 * Return the number of RCU callbacks still queued from the specified

 * CPU, which must be a nocbs CPU.

 */

static unsigned long rcu_get_n_cbs_nocb_cpu(struct rcu_data *rdp)

{

	return atomic_long_read(&rdp->nocb_q_count);

}



#else /* #ifdef CONFIG_RCU_NOCB_CPU */



/* No ->nocb_lock to acquire.  */
@@ -2108,11 +2099,6 @@ static void __init rcu_spawn_nocb_kthreads(void) 
{

}



static unsigned long rcu_get_n_cbs_nocb_cpu(struct rcu_data *rdp)

{

	return 0;

}



#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */



/*