qdisc->running seqcount operation is mainly used to do heuristic locking on q->busylock for locked qdisc, see qdisc_is_running() and __dev_xmit_skb().
So avoid doing seqcount operation for qdisc with TCQ_F_NOLOCK flag.
Acked-by: Jakub Kicinski kuba@kernel.org Tested-by: Vladimir Oltean vladimir.oltean@nxp.com # flexcan Signed-off-by: Yunsheng Lin linyunsheng@huawei.com --- include/net/sch_generic.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 1e62551..3ed6bcc 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -188,6 +188,7 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
nolock_empty: WRITE_ONCE(qdisc->empty, false); + return true; } else if (qdisc_is_running(qdisc)) { return false; } @@ -201,7 +202,6 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
static inline void qdisc_run_end(struct Qdisc *qdisc) { - write_seqcount_end(&qdisc->running); if (qdisc->flags & TCQ_F_NOLOCK) { spin_unlock(&qdisc->seqlock);
@@ -210,6 +210,8 @@ static inline void qdisc_run_end(struct Qdisc *qdisc) clear_bit(__QDISC_STATE_MISSED, &qdisc->state); __netif_schedule(qdisc); } + } else { + write_seqcount_end(&qdisc->running); } }