Re: [PATCH net-next v4 2/4] net: tcp: allow zero-window ACK update the window

From: Eric Dumazet
Date: Fri Aug 11 2023 - 03:38:12 EST


On Fri, Aug 11, 2023 at 5:01 AM <menglong8.dong@xxxxxxxxx> wrote:
>
> From: Menglong Dong <imagedong@xxxxxxxxxxx>
>
> Fow now, an ACK can update the window in following case, according to
> the tcp_may_update_window():
>
> 1. the ACK acknowledged new data
> 2. the ACK has new data
> 3. the ACK expand the window and the seq of it is valid
>
> Now, we allow the ACK update the window if the window is 0, and the
> seq/ack of it is valid. This is for the case that the receiver replies
> an zero-window ACK when it is under memory stress and can't queue the new
> data.
>
> Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>