Commit 816219a8 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-sched-fixes-after-recent-qdisc-running-changes' 

Eric Dumazet says:

====================
net: sched: fixes after recent qdisc->running changes

First patch fixes a plain bug in qdisc_run_begin().
Second patch removes a pair of atomic operations, increasing performance.
====================

Link: https://lore.kernel.org/r/20211019003402.2110017-1-eric.dumazet@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 05be9463 97604c65

include/net/sch_generic.h

+8 −4
Original line number Diff line number Diff line
@@ -38,10 +38,13 @@ enum qdisc_state_t { 
	__QDISC_STATE_DEACTIVATED,

	__QDISC_STATE_MISSED,

	__QDISC_STATE_DRAINING,

};



enum qdisc_state2_t {

	/* Only for !TCQ_F_NOLOCK qdisc. Never access it directly.

	 * Use qdisc_run_begin/end() or qdisc_is_running() instead.

	 */

	__QDISC_STATE_RUNNING,

	__QDISC_STATE2_RUNNING,

};



#define QDISC_STATE_MISSED	BIT(__QDISC_STATE_MISSED)
@@ -114,6 +117,7 @@ struct Qdisc { 
	struct gnet_stats_basic_sync bstats;

	struct gnet_stats_queue	qstats;

	unsigned long		state;

	unsigned long		state2; /* must be written under qdisc spinlock */

	struct Qdisc            *next_sched;

	struct sk_buff_head	skb_bad_txq;
@@ -154,7 +158,7 @@ static inline bool qdisc_is_running(struct Qdisc *qdisc) 
{

	if (qdisc->flags & TCQ_F_NOLOCK)

		return spin_is_locked(&qdisc->seqlock);

	return test_bit(__QDISC_STATE_RUNNING, &qdisc->state);

	return test_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);

}



static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc)
@@ -217,7 +221,7 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc) 
		 */

		return spin_trylock(&qdisc->seqlock);

	}

	return test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state);

	return !__test_and_set_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);

}



static inline void qdisc_run_end(struct Qdisc *qdisc)
@@ -229,7 +233,7 @@ static inline void qdisc_run_end(struct Qdisc *qdisc) 
				      &qdisc->state)))

			__netif_schedule(qdisc);

	} else {

		clear_bit(__QDISC_STATE_RUNNING, &qdisc->state);

		__clear_bit(__QDISC_STATE2_RUNNING, &qdisc->state2);

	}

}