tcp: add hrtimer slack to sack compression

Add a sysctl to control hrtimer slack, default of 100 usec.

This gives the opportunity to reduce system overhead,
and help very short RTT flows.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2020-04-30 10:35:43 -07:00
committed by David S. Miller
parent ccd0628fca
commit a70437cc09
5 changed files with 20 additions and 2 deletions

View File

@@ -5324,8 +5324,9 @@ send_now:
delay = min_t(unsigned long, sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns,
rtt * (NSEC_PER_USEC >> 3)/20);
sock_hold(sk);
hrtimer_start(&tp->compressed_ack_timer, ns_to_ktime(delay),
HRTIMER_MODE_REL_PINNED_SOFT);
hrtimer_start_range_ns(&tp->compressed_ack_timer, ns_to_ktime(delay),
sock_net(sk)->ipv4.sysctl_tcp_comp_sack_slack_ns,
HRTIMER_MODE_REL_PINNED_SOFT);
}
static inline void tcp_ack_snd_check(struct sock *sk)