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Commit 5ee832db authored by Eric Dumazet's avatar Eric Dumazet Committed by Linus Torvalds
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[PATCH] rcu: keep rcu callback event counter 



This makes call_rcu() keep track of how many events there are on the RCU
list, and cause a reschedule event when the list gets too long.

This helps keep RCU event lists down.

Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent cc675230

include/linux/rcupdate.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -94,6 +94,7 @@ struct rcu_data { 
	long  	       	batch;           /* Batch # for current RCU batch */

	long  	       	batch;           /* Batch # for current RCU batch */

	struct rcu_head *nxtlist;

	struct rcu_head *nxtlist;

	struct rcu_head **nxttail;

	struct rcu_head **nxttail;

	long            count; /* # of queued items */

	struct rcu_head *curlist;

	struct rcu_head *curlist;

	struct rcu_head **curtail;

	struct rcu_head **curtail;

	struct rcu_head *donelist;

	struct rcu_head *donelist;

kernel/rcupdate.c

+11 −0
Original line number Original line Diff line number Diff line
@@ -109,6 +109,10 @@ void fastcall call_rcu(struct rcu_head *head, 
	rdp = &__get_cpu_var(rcu_data);

	rdp = &__get_cpu_var(rcu_data);

	*rdp->nxttail = head;

	*rdp->nxttail = head;

	rdp->nxttail = &head->next;

	rdp->nxttail = &head->next;



	if (unlikely(++rdp->count > 10000))

		set_need_resched();



	local_irq_restore(flags);

	local_irq_restore(flags);

}

}
@@ -140,6 +144,12 @@ void fastcall call_rcu_bh(struct rcu_head *head, 
	rdp = &__get_cpu_var(rcu_bh_data);

	rdp = &__get_cpu_var(rcu_bh_data);

	*rdp->nxttail = head;

	*rdp->nxttail = head;

	rdp->nxttail = &head->next;

	rdp->nxttail = &head->next;

	rdp->count++;

/*

 *  Should we directly call rcu_do_batch() here ?

 *  if (unlikely(rdp->count > 10000))

 *      rcu_do_batch(rdp);

 */

	local_irq_restore(flags);

	local_irq_restore(flags);

}

}
@@ -157,6 +167,7 @@ static void rcu_do_batch(struct rcu_data *rdp) 
		next = rdp->donelist = list->next;

		next = rdp->donelist = list->next;

		list->func(list);

		list->func(list);

		list = next;

		list = next;

		rdp->count--;

		if (++count >= maxbatch)

		if (++count >= maxbatch)

			break;

			break;

	}

	}