Commit d3e0f575 authored by Yunsheng Lin's avatar Yunsheng Lin Committed by David S. Miller
Browse files

net: sched: remove qdisc->empty for lockless qdisc 



As MISSED and DRAINING state are used to indicate a non-empty
qdisc, qdisc->empty is not longer needed, so remove it.

Acked-by: default avatarJakub Kicinski <kuba@kernel.org>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # flexcan
Signed-off-by: default avatarYunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c4fef01b

include/net/sch_generic.h

+3 −10
Original line number Diff line number Diff line
@@ -117,8 +117,6 @@ struct Qdisc { 
	spinlock_t		busylock ____cacheline_aligned_in_smp;

	spinlock_t		seqlock;



	/* for NOLOCK qdisc, true if there are no enqueued skbs */

	bool			empty;

	struct rcu_head		rcu;



	/* private data */
@@ -165,7 +163,7 @@ static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 
static inline bool qdisc_is_empty(const struct Qdisc *qdisc)

{

	if (qdisc_is_percpu_stats(qdisc))

		return READ_ONCE(qdisc->empty);

		return nolock_qdisc_is_empty(qdisc);

	return !READ_ONCE(qdisc->q.qlen);

}
@@ -173,7 +171,7 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc) 
{

	if (qdisc->flags & TCQ_F_NOLOCK) {

		if (spin_trylock(&qdisc->seqlock))

			goto nolock_empty;

			return true;



		/* If the MISSED flag is set, it means other thread has

		 * set the MISSED flag before second spin_trylock(), so
@@ -195,12 +193,7 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc) 
		/* Retry again in case other CPU may not see the new flag

		 * after it releases the lock at the end of qdisc_run_end().

		 */

		if (!spin_trylock(&qdisc->seqlock))

			return false;



nolock_empty:

		WRITE_ONCE(qdisc->empty, false);

		return true;

		return spin_trylock(&qdisc->seqlock);

	} else if (qdisc_is_running(qdisc)) {

		return false;

	}

net/sched/sch_generic.c

+0 −3
Original line number Diff line number Diff line
@@ -725,8 +725,6 @@ static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc) 
		need_retry = false;



		goto retry;

	} else {

		WRITE_ONCE(qdisc->empty, true);

	}



	return skb;
@@ -927,7 +925,6 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 
	sch->enqueue = ops->enqueue;

	sch->dequeue = ops->dequeue;

	sch->dev_queue = dev_queue;

	sch->empty = true;

	dev_hold(dev);

	refcount_set(&sch->refcnt, 1);