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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!spool.mu.edu!howland.reston.ans.net!nntp.coast.net!netnews.worldnet.att.net!cbgw2.att.com!nntphub.cb.lucent.com!news From: "John S. Dyson" <dyson@inuxs.att.com> Newsgroups: comp.os.linux.networking,comp.unix.bsd.netbsd.misc,comp.unix.bsd.freebsd.misc Subject: Re: TCP latency Date: Mon, 15 Jul 1996 14:42:07 -0500 Organization: Lucent Technologies, Columbus, Ohio Lines: 45 Message-ID: <31EA9F0F.41C67EA6@inuxs.att.com> References: <31E3D9E2.41C67EA6@dyson.iquest.net> <4s5bl2$qpg@linux.cs.Helsinki.FI> <31E664EB.167EB0E7@inuxs.att.com> <4se37p$7en@news.swan.ac.uk> NNTP-Posting-Host: dyson.inh.lucent.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.0 (X11; I; FreeBSD 2.1-STABLE i386) Xref: euryale.cc.adfa.oz.au comp.os.linux.networking:45311 comp.unix.bsd.netbsd.misc:4060 comp.unix.bsd.freebsd.misc:23654 Alan Cox wrote: > > In article <31E664EB.167EB0E7@inuxs.att.com> "John S. Dyson" <dyson@inuxs.att.com> writes: > >are being fixed? Hmmm... Looks like the NEW IMPROVED Linux TCP suite > >is about the same perf as the BSD code... Luckily, there is movement > >afoot to clean-up the BSD networking code, and I wouldn't be too awful > >suprised if it betters Linux. (Some pieces of it haven't been reworked > >in years.) > > About time the BSD folks woke up. Last year several BSD people really took > the piss at the idea of the Linux folks catching up. Well we've passed you > (at least on these benchmarks [save the validity debate ;)]). > The validity of the benchmarks (or actually the importance of what they measure) is critical. There are numbers that we can make better, but the effort is best spent in areas where the performance difference matters more often. > > >I get about 17-19 MB/sec on localhost also on FreeBSD. The MBUF > >code is not very inefficient in reality. Again, it is hard to > >come to any conclusions given different hardware. > > Dump mbufs, go for linear buffers, add copy and checksum passes and your > code will start to look like what everyone else has been doing to the BSD > stack while netbsd and freebsd stayed almost unchanging. It'll also start > to look remarkably like the Linux stack providing you fix the poor > granularity timers as well. > The low granularity timers are a flaw (ok, so I have admitted to a problem in the BSD code), but the performance numbers are not demonstrating the superiority of the Linux stack in real world applications. I think that it is time for the people making the superior performance claims to show the measurments that back up the claims. However, they should also be willing to have the claims challenged. You know, I have made very few, if any, performance claims in this thread, and I have mostly asked for data to back up the claims made by others. Very little has been forthcoming. The ONLY substantiated claim is that the no-load latency on the Linux networking is better with a specific network adapter driver. John