On Tue, 21 Feb 2006 19:54:56 +0300, in sentex.lists.freebsd.hackers you wrote:
> Good day! > I've obtained the following strang results with the em Ethernet interface >speeds on a 6.1-PRERELEASE: > Polling on: > UDP stream to FreeBSD: 327843.84 Kbit/sec, > TCP stream to FreeBSD: 524550.12 Kbit/sec. > Polling off: > UDP stream to FreeBSD: 740409.38 Kbit/sec, > TCP stream to FreeBSD: 794348.44 Kbit/sec. > > It is funny that TCP speed is greater than UDP. It can be related to the >hardware, not to the OS, because I've seen such behaviour on a linux-2.6. >But on linux-2.4 with the same hardware as for FreeBSD and with the same >source host I've got > UDP stream to Linux: 927891.44 Kbit/sec, > TCP stream to Linux: 850202.50 Kbit/sec. >The figures are higher and UDP rate > TCP rate. > I found that setting kern.polling.idle_poll=1 made a big difference to the forwarding rate. Also, on your tcp tests, try sysctl -w net.inet.tcp.inflight.enable=0 You might also adjust the amount of CPU allocated to userland when using polling. Without polling, I found I was able to livelock the middle box with just a dozen rules. I had FreeBSD boxA ------FreeBSD-B---FreeBSD-C Where A = AMD 3800 with PCI-e BGE B = P4 3Ghz with PCI-X 82546EB Dual Port Gigabit C = AMD 3800 with PCI-e BGE using netrate and iperf from A to C going across B, I had to switch to polling so as not to live lock B using /usr/src/tools/tools/netrate/netblast. Without ipfw or pflog, it was not an issue. but load up ipfw or pf, B would become unresponsive in non polling mode. > The questions: can anyone explain the relation 'TCP rate > UDP rate'? Why >polling slows down the interface? And can FreeBSD stack can be tuned to >get the Linux performance? > > Kernel config deviations from GENERIC: >options SCHED_ULE get rid of that and use SCHED_4BSD ---Mike >options ADAPTIVE_GIANT >device pf >device pflog >device pfsync > > System is running at hz = 1000. > > Thanks! -------------------------------------------------------- Mike Tancsa, Sentex communications http://www.sentex.net Providing Internet Access since 1994 [EMAIL PROTECTED], (http://www.tancsa.com) _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"