Commit e6d14070 authored Mar 22, 2019 by Eric Dumazet Committed by David S. Miller Mar 23, 2019

tcp: remove conditional branches from tcp_mstamp_refresh()



tcp_clock_ns() (aka ktime_get_ns()) is using monotonic clock,
so the checks we had in tcp_mstamp_refresh() are no longer
relevant.

This patch removes cpu stall (when the cache line is not hot)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a7a01ab3

net/ipv4/tcp_output.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -52,12 +52,8 @@ void tcp_mstamp_refresh(struct tcp_sock *tp)
		{
		u64 val = tcp_clock_ns();

		if (val > tp->tcp_clock_cache)
		tp->tcp_clock_cache = val;

		val = div_u64(val, NSEC_PER_USEC);
		if (val > tp->tcp_mstamp)
		tp->tcp_mstamp = val;
		tp->tcp_mstamp = div_u64(val, NSEC_PER_USEC);
		}

		static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,