From: Eric Dumazet <eric.duma...@gmail.com> Date: Thu, 15 Sep 2016 09:33:02 -0700
> From: Eric Dumazet <eduma...@google.com> > > With large BDP TCP flows and lossy networks, it is very important > to keep a low number of skbs in the write queue. > > RACK and SACK processing can perform a linear scan of it. > > We should avoid putting any payload in skb->head, so that SACK > shifting can be done if needed. > > With this patch, we allow to pack ~0.5 MB per skb instead of > the 64KB initially cooked at tcp_sendmsg() time. > > This gives a reduction of number of skbs in write queue by eight. > tcp_rack_detect_loss() likes this. > > We still allow payload in skb->head for first skb put in the queue, > to not impact RPC workloads. > > Signed-off-by: Eric Dumazet <eduma...@google.com> > Cc: Yuchung Cheng <ych...@google.com> Applied.
