From: Eric Dumazet <eric.duma...@gmail.com>
Date: Wed, 16 Nov 2016 14:54:50 -0800
> From: Eric Dumazet <eduma...@google.com>
>
> Callers of netpoll_poll_lock() own NAPI_STATE_SCHED
>
> Callers of netpoll_poll_unlock() have BH blocked between
> the NAPI_STATE_SCHED being cleared and poll_lock is released.
>
> We can avoid the spinlock which has no contention, and use cmpxchg()
> on poll_owner which we need to set anyway.
>
> This removes a possible lockdep violation after the cited commit,
> since sk_busy_loop() re-enables BH before calling busy_poll_stop()
>
> Fixes: 217f69743681 ("net: busy-poll: allow preemption in sk_busy_loop()")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
Applied, thanks Eric.
