From: Eric Dumazet <eduma...@google.com> Date: Tue, 16 Apr 2019 10:55:20 -0700
> For some reason, tcp_grow_window() correctly tests if enough room > is present before attempting to increase tp->rcv_ssthresh, > but does not prevent it to grow past tcp_space() > > This is causing hard to debug issues, like failing > the (__tcp_select_window(sk) >= tp->rcv_wnd) test > in __tcp_ack_snd_check(), causing ACK delays and possibly > slow flows. > > Depending on tcp_rmem[2], MTU, skb->len/skb->truesize ratio, > we can see the problem happening on "netperf -t TCP_RR -- -r 2000,2000" > after about 60 round trips, when the active side no longer sends > immediate acks. > > This bug predates git history. > > Signed-off-by: Eric Dumazet <eduma...@google.com> > Acked-by: Soheil Hassas Yeganeh <soh...@google.com> > Acked-by: Neal Cardwell <ncardw...@google.com> > Acked-by: Wei Wang <wei...@google.com> Applied and queued up for -stable, thanks Eric.
