tcp: switch pacing timer to softirq based hrtimer
linux-4.16 got support for softirq based hrtimers.
TCP can switch its pacing hrtimer to this variant, since this
avoids going through a tasklet and some atomic operations.
pacing timer logic looks like other (jiffies based) tcp timers.
v2: use hrtimer_try_to_cancel() in tcp_clear_xmit_timers()
to correctly release reference on socket if needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index cf803fe..3b1d617 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -557,7 +557,9 @@ void tcp_fin(struct sock *sk);
void tcp_init_xmit_timers(struct sock *);
static inline void tcp_clear_xmit_timers(struct sock *sk)
{
- hrtimer_cancel(&tcp_sk(sk)->pacing_timer);
+ if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1)
+ sock_put(sk);
+
inet_csk_clear_xmit_timers(sk);
}