From c9f1f58dc2eba550f208809d272bf0b14f41edba Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 12 Dec 2017 06:34:19 -0800 Subject: [PATCH] net: sk_pacing_shift_update() helper In commit 3a9b76fd0db9 ("tcp: allow drivers to tweak TSQ logic") I gave a code sample to set sk->sk_pacing_shift that was not complete. Better add a helper that can be used by drivers without worries, and maybe amended in the future. A wifi driver might use it from its ndo_start_xmit() Following call would setup TCP to allow up to ~8ms of queued data per flow. sk_pacing_shift_update(skb->sk, 7); Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/sock.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index 9155da422692..9a9047268d37 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2407,4 +2407,15 @@ static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto) return *proto->sysctl_rmem; } +/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10) + * Some wifi drivers need to tweak it to get more chunks. + * They can use this helper from their ndo_start_xmit() + */ +static inline void sk_pacing_shift_update(struct sock *sk, int val) +{ + if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val) + return; + sk->sk_pacing_shift = val; +} + #endif /* _SOCK_H */