Commit ab14f180 authored Jan 24, 2022 by David Ahern Committed by Jakub Kicinski Jan 25, 2022

net: Adjust sk_gso_max_size once when set



sk_gso_max_size is set based on the dst dev. Both users of it
adjust the value by the same offset - (MAX_TCP_HEADER + 1). Rather
than compute the same adjusted value on each call do the adjustment
once when set.

Signed-off-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220125024511.27480-1-dsahern@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 6b0671a2

net/core/sock.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -2266,6 +2266,7 @@ void sk_setup_caps(struct sock sk, struct dst_entry dst)
		sk->sk_route_caps \|= NETIF_F_SG \| NETIF_F_HW_CSUM;
		/* pairs with the WRITE_ONCE() in netif_set_gso_max_size() */
		sk->sk_gso_max_size = READ_ONCE(dst->dev->gso_max_size);
		sk->sk_gso_max_size -= (MAX_TCP_HEADER + 1);
		/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
		max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
		}

net/ipv4/tcp.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -894,8 +894,7 @@ static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
		return mss_now;

		/* Note : tcp_tso_autosize() will eventually split this later */
		new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER;
		new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal);
		new_size_goal = tcp_bound_to_half_wnd(tp, sk->sk_gso_max_size);

		/* We try hard to avoid divides here */
		size_goal = tp->gso_segs * mss_now;

net/ipv4/tcp_output.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1960,7 +1960,7 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,

		bytes = min_t(unsigned long,
		sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift),
		sk->sk_gso_max_size - 1 - MAX_TCP_HEADER);
		sk->sk_gso_max_size);

		/* Goal is to send at least one packet per ms,
		* not one big TSO packet every 100 ms.