From dcb8c9b4373a583451b1b8a3e916d33de273633d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 28 Feb 2018 14:40:46 -0800 Subject: tcp_bbr: better deal with suboptimal GSO (II) This is second part of dealing with suboptimal device gso parameters. In first patch (350c9f484bde "tcp_bbr: better deal with suboptimal GSO") we dealt with devices having low gso_max_segs Some devices lower gso_max_size from 64KB to 16 KB (r8152 is an example) In order to probe an optimal cwnd, we want BBR being not sensitive to whatever GSO constraint a device can have. This patch removes tso_segs_goal() CC callback in favor of min_tso_segs() for CC wanting to override sysctl_tcp_min_tso_segs Next patch will remove bbr->tso_segs_goal since it does not have to be persistent. Signed-off-by: Eric Dumazet Acked-by: Neal Cardwell Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 49d043de3476..383cac0ff0ec 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1703,8 +1703,8 @@ static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp, /* Return how many segs we'd like on a TSO packet, * to send one TSO packet per ms */ -u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, - int min_tso_segs) +static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, + int min_tso_segs) { u32 bytes, segs; @@ -1720,7 +1720,6 @@ u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, return segs; } -EXPORT_SYMBOL(tcp_tso_autosize); /* Return the number of segments we want in the skb we are transmitting. * See if congestion control module wants to decide; otherwise, autosize. @@ -1728,11 +1727,13 @@ EXPORT_SYMBOL(tcp_tso_autosize); static u32 tcp_tso_segs(struct sock *sk, unsigned int mss_now) { const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; - u32 tso_segs = ca_ops->tso_segs_goal ? ca_ops->tso_segs_goal(sk) : 0; + u32 min_tso, tso_segs; - if (!tso_segs) - tso_segs = tcp_tso_autosize(sk, mss_now, - sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs); + min_tso = ca_ops->min_tso_segs ? + ca_ops->min_tso_segs(sk) : + sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs; + + tso_segs = tcp_tso_autosize(sk, mss_now, min_tso); return min_t(u32, tso_segs, sk->sk_gso_max_segs); } -- cgit v1.2.3-55-g7522