Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sun, 2016-12-04 at 00:03 +0100, Steinar H. Gunderson wrote: > On Sat, Dec 03, 2016 at 02:55:37PM -0800, Eric Dumazet wrote: > > Note that starting from linux-4.4, e1000e gets gro_flush_timeout that > > would help this precise workload > > > >

Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sat, 2016-12-03 at 15:02 -0800, Eric Dumazet wrote: > On Sat, 2016-12-03 at 14:55 -0800, Eric Dumazet wrote: > > > Perfect. > > > > Note that starting from linux-4.4, e1000e gets gro_flush_timeout that > > would help this precise workload > > Also it appears the sender uses a lot of

Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sat, 2016-12-03 at 14:55 -0800, Eric Dumazet wrote: > Perfect. > > Note that starting from linux-4.4, e1000e gets gro_flush_timeout that > would help this precise workload Also it appears the sender uses a lot of relatively small segments (8220 bytes at a time), with PSH, so GRO wont be able

Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sat, 2016-12-03 at 23:13 +0100, Steinar H. Gunderson wrote: > On Sat, Dec 03, 2016 at 01:50:37PM -0800, Eric Dumazet wrote: > >> Note, the tcpdump is done at the receiver. I don't know if this changes the > >> analysis. > > If you have access to the receiver, I would be interested to know > >

Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sat, 2016-12-03 at 22:34 +0100, Steinar H. Gunderson wrote: > On Sat, Dec 03, 2016 at 01:07:40PM -0800, Eric Dumazet wrote: > > What I meant was that we receive ACKS in bursts, with huge gaps between > > them. > > Note, the tcpdump is done at the receiver. I don't know if this changes the >

Re: [aqm] [Bloat] TCP BBR paper is now generally available

> On 3 Dec, 2016, at 23:07, Eric Dumazet wrote: > > I do not attend IETF meetings so maybe my words are not exact. > > What I meant was that we receive ACKS in bursts, with huge gaps between > them. > > Look at tsval/tsecr, and that all ACKS are received in a 20 usec

Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sat, 2016-12-03 at 22:26 +0200, Jonathan Morton wrote: > > On 3 Dec, 2016, at 22:20, Eric Dumazet wrote: > > > > Huge ACK decimation it seems. > > That extract does not show ACK decimation. It shows either jumbo > frames or offload aggregation in a send burst, and

Re: [aqm] [Bloat] TCP BBR paper is now generally available

> On 3 Dec, 2016, at 22:20, Eric Dumazet wrote: > > Huge ACK decimation it seems. That extract does not show ACK decimation. It shows either jumbo frames or offload aggregation in a send burst, and ordinary delayed-acks each covering at most two packets received.

Re: [aqm] [Bloat] TCP BBR paper is now generally available

On Sat, 2016-12-03 at 20:13 +0100, Steinar H. Gunderson wrote: > On Sat, Dec 03, 2016 at 08:03:50AM -0500, Neal Cardwell wrote: > > Thanks for the report, Steinar. This is the first report we've had > > like this, but it would be interesting to find out what's going on. > > > > Even if you don't

Re: [aqm] [Bloat] TCP BBR paper is now generally available

Thanks for the report, Steinar. This is the first report we've had like this, but it would be interesting to find out what's going on. Even if you don't have time to apply the patches Eric mentions, it would be hugely useful if the next time you have a slow transfer like that you could post a