Replace state2 field with a boolean. Move it to a hole between qstats and state so that we shrink Qdisc by a full cache line. Signed-off-by: Eric Dumazet --- include/net/sch_generic.h | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 32e9961570b467b6066f1bb2c00ff1a270e342bc..31561291bc92fd70d4d3ca8f5f7dbc4c94c895a0 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -41,13 +41,6 @@ enum qdisc_state_t { __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_STATE2_RUNNING, -}; - #define QDISC_STATE_MISSED BIT(__QDISC_STATE_MISSED) #define QDISC_STATE_DRAINING BIT(__QDISC_STATE_DRAINING) @@ -117,8 +110,8 @@ struct Qdisc { struct qdisc_skb_head q; struct gnet_stats_basic_sync bstats; struct gnet_stats_queue qstats; + bool running; /* must be written under qdisc spinlock */ unsigned long state; - unsigned long state2; /* must be written under qdisc spinlock */ struct Qdisc *next_sched; struct sk_buff_head skb_bad_txq; @@ -167,7 +160,7 @@ 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_STATE2_RUNNING, &qdisc->state2); + return READ_ONCE(qdisc->running); } static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc) @@ -210,7 +203,10 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc) */ return spin_trylock(&qdisc->seqlock); } - return !__test_and_set_bit(__QDISC_STATE2_RUNNING, &qdisc->state2); + if (READ_ONCE(qdisc->running)) + return false; + WRITE_ONCE(qdisc->running, true); + return true; } static inline void qdisc_run_end(struct Qdisc *qdisc) @@ -228,7 +224,7 @@ static inline void qdisc_run_end(struct Qdisc *qdisc) &qdisc->state))) __netif_schedule(qdisc); } else { - __clear_bit(__QDISC_STATE2_RUNNING, &qdisc->state2); + WRITE_ONCE(qdisc->running, false); } } -- 2.51.0.618.g983fd99d29-goog