diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 45 |
1 files changed, 43 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index be97c440ecd5..5baa4691074f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6926,6 +6926,43 @@ static enum hrtimer_restart napi_watchdog(struct hrtimer *timer) return HRTIMER_NORESTART; } +static void napi_stop_kthread(struct napi_struct *napi) +{ + unsigned long val, new; + + /* Wait until the napi STATE_THREADED is unset. */ + while (true) { + val = READ_ONCE(napi->state); + + /* If napi kthread own this napi or the napi is idle, + * STATE_THREADED can be unset here. + */ + if ((val & NAPIF_STATE_SCHED_THREADED) || + !(val & NAPIF_STATE_SCHED)) { + new = val & (~NAPIF_STATE_THREADED); + } else { + msleep(20); + continue; + } + + if (try_cmpxchg(&napi->state, &val, new)) + break; + } + + /* Once STATE_THREADED is unset, wait for SCHED_THREADED to be unset by + * the kthread. + */ + while (true) { + if (!test_bit(NAPIF_STATE_SCHED_THREADED, &napi->state)) + break; + + msleep(20); + } + + kthread_stop(napi->thread); + napi->thread = NULL; +} + int dev_set_threaded(struct net_device *dev, bool threaded) { struct napi_struct *napi; @@ -6961,8 +6998,12 @@ int dev_set_threaded(struct net_device *dev, bool threaded) * softirq mode will happen in the next round of napi_schedule(). * This should not cause hiccups/stalls to the live traffic. */ - list_for_each_entry(napi, &dev->napi_list, dev_list) - assign_bit(NAPI_STATE_THREADED, &napi->state, threaded); + list_for_each_entry(napi, &dev->napi_list, dev_list) { + if (!threaded && napi->thread) + napi_stop_kthread(napi); + else + assign_bit(NAPI_STATE_THREADED, &napi->state, threaded); + } return err; } |