On 05/17/2018 08:40 AM, Eric Dumazet wrote: > > > On 05/17/2018 08:14 AM, Neal Cardwell wrote:
>> Any particular motivation for the 2.5ms here? It might be nice to match the >> existing TSO autosizing dynamics and use 1ms here instead of having a >> separate new constant of 2.5ms. Smaller time scales here should lead to >> less burstiness and queue pressure from data packets in the network, and we >> know from experience that the CPU overhead of 1ms chunks is acceptable. > > This came from my tests on wifi really :) > > I also had the idea to make this threshold adjustable for wifi, like we did > for sk_pacing_shift. > > (On wifi, we might want to increase the max delay between ACK) > > So maybe use 1ms delay, when sk_pacing_shift == 10, but increase it if > sk_pacing_shift has been lowered. > > BTW, maybe my changelog or patch is not clear enough : As soon as some packets are received in order, we send an ACK, even if the timer was armed. (This is the beginning of __tcp_ack_snd_check()) When this ACK is sent, timer is canceled (in tcp_event_ack_sent())
