diff options
Diffstat (limited to 'include/net/sch_generic.h')
| -rw-r--r-- | include/net/sch_generic.h | 33 |
1 files changed, 14 insertions, 19 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 7882e3aa6448..baad2ab4d971 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -38,6 +38,10 @@ enum qdisc_state_t { __QDISC_STATE_DEACTIVATED, __QDISC_STATE_MISSED, __QDISC_STATE_DRAINING, + /* Only for !TCQ_F_NOLOCK qdisc. Never access it directly. + * Use qdisc_run_begin/end() or qdisc_is_running() instead. + */ + __QDISC_STATE_RUNNING, }; #define QDISC_STATE_MISSED BIT(__QDISC_STATE_MISSED) @@ -108,7 +112,6 @@ struct Qdisc { struct sk_buff_head gso_skb ____cacheline_aligned_in_smp; struct qdisc_skb_head q; struct gnet_stats_basic_sync bstats; - seqcount_t running; struct gnet_stats_queue qstats; unsigned long state; struct Qdisc *next_sched; @@ -143,11 +146,15 @@ static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc) return NULL; } +/* For !TCQ_F_NOLOCK qdisc: callers must either call this within a qdisc + * root_lock section, or provide their own memory barriers -- ordering + * against qdisc_run_begin/end() atomic bit operations. + */ static inline bool qdisc_is_running(struct Qdisc *qdisc) { if (qdisc->flags & TCQ_F_NOLOCK) return spin_is_locked(&qdisc->seqlock); - return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; + return test_bit(__QDISC_STATE_RUNNING, &qdisc->state); } static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc) @@ -167,6 +174,9 @@ static inline bool qdisc_is_empty(const struct Qdisc *qdisc) return !READ_ONCE(qdisc->q.qlen); } +/* For !TCQ_F_NOLOCK qdisc, qdisc_run_begin/end() must be invoked with + * the qdisc root lock acquired. + */ static inline bool qdisc_run_begin(struct Qdisc *qdisc) { if (qdisc->flags & TCQ_F_NOLOCK) { @@ -206,15 +216,8 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc) * after it releases the lock at the end of qdisc_run_end(). */ return spin_trylock(&qdisc->seqlock); - } else if (qdisc_is_running(qdisc)) { - return false; } - /* Variant of write_seqcount_begin() telling lockdep a trylock - * was attempted. - */ - raw_write_seqcount_begin(&qdisc->running); - seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); - return true; + return test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state); } static inline void qdisc_run_end(struct Qdisc *qdisc) @@ -226,7 +229,7 @@ static inline void qdisc_run_end(struct Qdisc *qdisc) &qdisc->state))) __netif_schedule(qdisc); } else { - write_seqcount_end(&qdisc->running); + clear_bit(__QDISC_STATE_RUNNING, &qdisc->state); } } @@ -592,14 +595,6 @@ static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) return qdisc_lock(root); } -static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) -{ - struct Qdisc *root = qdisc_root_sleeping(qdisc); - - ASSERT_RTNL(); - return &root->running; -} - static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) { return qdisc->dev_queue->dev; |