Hi Matt, On Wed, Mar 11, 2026 at 07:27:34PM +0100, Matthieu Baerts wrote: > Hi Simon, > > On 09/03/2026 09:02, Simon Baatz via B4 Relay wrote: > > From: Simon Baatz <[email protected]> > > > > MPTCP shares a receive window across subflows and applies it at the > > subflow level by adjusting each subflow's rcv_wnd when needed. With > > the new TCP tracking of the maximum advertised window sequence, > > rcv_mwnd_seq must stay consistent with these subflow-level rcv_wnd > > adjustments. > > Thank you for these modifications! > > > Signed-off-by: Simon Baatz <[email protected]> > > --- > > net/mptcp/options.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/net/mptcp/options.c b/net/mptcp/options.c > > index > > 43df4293f58bfbd8a8df6bf24b9f15e0f9e238f6..8a1c5698983cff3082d68290626dd8f1e044527f > > 100644 > > --- a/net/mptcp/options.c > > +++ b/net/mptcp/options.c > > (...) > > > @@ -1338,8 +1339,9 @@ static void mptcp_set_rwin(struct tcp_sock *tp, > > struct tcphdr *th) > > */ > > rcv_wnd_new = rcv_wnd_old; > > win = rcv_wnd_old - ack_seq; > > - tp->rcv_wnd = min_t(u64, win, U32_MAX); > > - new_win = tp->rcv_wnd; > > + new_win = min_t(u64, win, U32_MAX); > > + tp->rcv_wnd = new_win; > > Out of curiosity, why did you change the two lines above? > (even if it makes sense, the diff is a bit confusing, and the commit > message doesn't mention this :) )
I wanted to keep tcp_update_max_rcv_wnd_seq() calls close to the respective update sites (same pattern everywhere). In the original form tp->rcv_wnd = min_t(u64, win, U32_MAX); tcp_update_max_rcv_wnd_seq(tp); new_win = tp->rcv_wnd; the ordering suggests that tcp_update_max_rcv_wnd_seq() might modify tp->rcv_wnd. So, I changed it for legibility. Now, I realize it made the diff harder to read. I might have optimized the wrong metric here ;-) > > > + tcp_update_max_rcv_wnd_seq(tp); > > > This patch adding this new helper each time rcv_wnd is modified looks > good to me: > > Reviewed-by: Matthieu Baerts (NGI0) <[email protected]> > > > Note: just in case a new version is needed, checkpatch reported an error > in patch 4/6 because of a trailing whitespace (+ No space is necessary > after a cast in patch 1/6), see: > > https://github.com/multipath-tcp/mptcp_net-next/actions/runs/22844479818 Thanks. I will change that if there is a v4. -- Simon Baatz <[email protected]>
