Commit c9f1f58d authored Dec 12, 2017 by Eric Dumazet Committed by David S. Miller Dec 13, 2017

net: sk_pacing_shift_update() helper



In commit 3a9b76fd ("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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent eb793583

include/net/sock.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -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 */

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