enum qdisc_state_t {
__QDISC_STATE_SCHED,
__QDISC_STATE_DEACTIVATED,
- __QDISC_STATE_RUNNING,
};
struct qdisc_size_table {
refcount_t refcnt;
spinlock_t busylock ____cacheline_aligned_in_smp;
+ spinlock_t seqlock;
};
static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
refcount_inc(&qdisc->refcnt);
}
-static inline bool qdisc_is_running(const struct Qdisc *qdisc)
+static inline bool qdisc_is_running(struct Qdisc *qdisc)
{
if (qdisc->flags & TCQ_F_NOLOCK)
- return test_bit(__QDISC_STATE_RUNNING, &qdisc->state);
+ return spin_is_locked(&qdisc->seqlock);
return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
}
static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
if (qdisc->flags & TCQ_F_NOLOCK) {
- if (test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state))
+ if (!spin_trylock(&qdisc->seqlock))
return false;
} else if (qdisc_is_running(qdisc)) {
return false;
{
write_seqcount_end(&qdisc->running);
if (qdisc->flags & TCQ_F_NOLOCK)
- clear_bit(__QDISC_STATE_RUNNING, &qdisc->state);
+ spin_unlock(&qdisc->seqlock);
}
static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
lockdep_set_class(&sch->busylock,
dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
+ /* seqlock has the same scope of busylock, for NOLOCK qdisc */
+ spin_lock_init(&sch->seqlock);
+ lockdep_set_class(&sch->busylock,
+ dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
+
seqcount_init(&sch->running);
lockdep_set_class(&sch->running,
dev->qdisc_running_key ?: &qdisc_running_key);
qdisc = rtnl_dereference(dev_queue->qdisc);
if (qdisc) {
+ bool nolock = qdisc->flags & TCQ_F_NOLOCK;
+
+ if (nolock)
+ spin_lock_bh(&qdisc->seqlock);
spin_lock_bh(qdisc_lock(qdisc));
if (!(qdisc->flags & TCQ_F_BUILTIN))
qdisc_reset(qdisc);
spin_unlock_bh(qdisc_lock(qdisc));
+ if (nolock)
+ spin_unlock_bh(&qdisc->seqlock);
}
}