Re: [PATCH net] tcp: make TCP_USER_TIMEOUT accurate for zero window probes

From: Jakub Kicinski
Date: Fri Jan 22 2021 - 20:44:12 EST

On Fri, 22 Jan 2021 11:13:06 -0800 Enke Chen wrote:
> From: Enke Chen <enchen@xxxxxxxxxxxxxxxxxxxx>
> The TCP_USER_TIMEOUT is checked by the 0-window probe timer. As the
> timer has backoff with a max interval of about two minutes, the
> actual timeout for TCP_USER_TIMEOUT can be off by up to two minutes.
> In this patch the TCP_USER_TIMEOUT is made more accurate by taking it
> into account when computing the timer value for the 0-window probes.
> This patch is similar to the one that made TCP_USER_TIMEOUT accurate for
> RTOs in commit b701a99e431d ("tcp: Add tcp_clamp_rto_to_user_timeout()
> helper to improve accuracy").
> Signed-off-by: Enke Chen <enchen@xxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Neal Cardwell <ncardwell@xxxxxxxxxx>

This is targeting net, any guidance on Fixes / backporting?