Re: [PATCH net] tcp: fix potential underestimation on rcv_rtt

2017-12-13 Thread David Miller 
From: Wei Wang 
Date: Tue, 12 Dec 2017 16:28:58 -0800

> From: Wei Wang 
> 
> When ms timestamp is used, current logic uses 1us in
> tcp_rcv_rtt_update() when the real rcv_rtt is within 1 - 999us.
> This could cause rcv_rtt underestimation.
> Fix it by always using a min value of 1ms if ms timestamp is used.
> 
> Fixes: 645f4c6f2ebd ("tcp: switch rcv_rtt_est and rcvq_space to high
> resolution timestamps")
> 
> Signed-off-by: Wei Wang 
> Signed-off-by: Eric Dumazet 

Please, in the future, do not wrap long Fixes: tag lines.  Also, do
not add an empty line between Fixes: and other tags like Signed-off-by.
That are all tags and belong together as a seamless block of text.

Thank you.

Re: [PATCH net] tcp: fix potential underestimation on rcv_rtt

2017-12-13 Thread Neal Cardwell 
On Tue, Dec 12, 2017 at 7:28 PM, Wei Wang  wrote:
> From: Wei Wang 
>
> When ms timestamp is used, current logic uses 1us in
> tcp_rcv_rtt_update() when the real rcv_rtt is within 1 - 999us.
> This could cause rcv_rtt underestimation.
> Fix it by always using a min value of 1ms if ms timestamp is used.
>
> Fixes: 645f4c6f2ebd ("tcp: switch rcv_rtt_est and rcvq_space to high
> resolution timestamps")
>
> Signed-off-by: Wei Wang 
> Signed-off-by: Eric Dumazet 
> ---

Acked-by: Neal Cardwell 

Thanks!

neal