Re: [PATCH net-next,v3] tcp: Set pingpong threshold via sysctl

[Simon Horman]

On Wed, Oct 11, 2023 at 01:30:44PM -0700, Haiyang Zhang wrote:
> TCP pingpong threshold is 1 by default. But some applications, like SQL DB
> may prefer a higher pingpong threshold to activate delayed acks in quick
> ack mode for better performance.
> 
> The pingpong threshold and related code were changed to 3 in the year
> 2019 in:
>   commit 4a41f453bedf ("tcp: change pingpong threshold to 3")
> And reverted to 1 in the year 2022 in:
>   commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"")
> 
> There is no single value that fits all applications.
> Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for
> optimal performance based on the application needs.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> ---
> v3: Updated doc as suggested by Neal Cardwell.
>     Updated variable location in struct netns_ipv4 as suggested by Kuniyuki
>     Iwashima.
> 
> v2: Make it per-namesapce setting, and other updates suggested by Neal Cardwell,
> and Kuniyuki Iwashima.

Thanks,

this looks clean to me. It seems to address the review of v2.
And keeps the knob as syctl as discussed in v2.

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>