diff options
| -rw-r--r-- | net/core/dev.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 4420086f3aeb..53bef2aae378 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3719,8 +3719,12 @@ no_lock_out: * separate lock before trying to get qdisc main lock. * This permits qdisc->running owner to get the lock more * often and dequeue packets faster. + * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit + * and then other tasks will only enqueue packets. The packets will be + * sent after the qdisc owner is scheduled again. To prevent this + * scenario the task always serialize on the lock. */ - contended = qdisc_is_running(q); + contended = IS_ENABLED(CONFIG_PREEMPT_RT) || qdisc_is_running(q); if (unlikely(contended)) spin_lock(&q->busylock); |