Yes it is unacceptable. Alexander Bluhm <alexander.bl...@gmx.net> wrote:
> On Wed, Feb 03, 2021 at 11:20:04AM +0100, Claudio Jeker wrote: > > Just commit it. OK claudio@ > > If people see problems we can back it out again. > > This has huge impact on TCP performance. > > http://bluhm.genua.de/perform/results/2021-02-07T00%3A01%3A40Z/perform.html > > For a single TCP connection between to OpenBSD boxes, througput > drops by 77% from 3.1 GBit/sec to 710 MBit/sec. But with 100 > parallel connections the througput over all increases by 5%. > > Sending from Linux to OpenBSD increases by 72% from 3.5 GBit/sec > to 6.0 GBit/sec. > > Socket splicing from Linux to Linux via OpenBSD with 10 parallel > TCP connections increases by 25% from 3.5 GBit/sec from 1.8 GBit/sec > to 2.3 GBit/sec. > > It seems that sending less ACK packets improves performance if the > machine is limited by the CPU. But the TCP stack of OpenBSD is > sending 77% percent slower, if it does not receive enough ACKs. > This has no impact if we are measuring the combined througput of > many parallel connections. The Linux packet sending algorithm looks > unaffected by our more delayed acks. > > I think 77% slower between two OpenBSDs is not acceptable. > Do others see that, too? > > bluhm >
