Date: Tue, 12 Jul 2005 15:11:42 +0200 From: Alexis Yushin <alexis@ww.net> To: Danny Braniss <danny@cs.huji.ac.il> Cc: David Malone <dwmalone@maths.tcd.ie>, freebsd-net@freebsd.org, freebsd-stable@freebsd.org, Noritoshi Demizu <demizu@dd.iij4u.or.jp>, Luigi Rizzo <rizzo@icir.org> Subject: Re: tcp troughput weirdness Message-ID: <20050712131142.GA73214@virgin.ww.net> In-Reply-To: <E1DsIbz-000DjF-MH@cs1.cs.huji.ac.il> References: <20050712.185304.32727687.Noritoshi@Demizu.ORG> <E1DsIbz-000DjF-MH@cs1.cs.huji.ac.il>
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Hmm, Recently I've also been seeing less than what I'd expect tcp throughput on FreeBSD 5.4R machines. I've got six 5.4R boxes with dual Gigabit em interfaces. netperf gives me: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 65536 131072 131072 10.01 551.10 However scp/ftp etc doen't go above 200Mbit. I'd expect higher numbers? Alexis ps I've tried all of the sysctl and mtu tweakings... No change. Interesting is that netperf lo0 gives me about 2.5Gbit, but scp performs at about 128Mbit while system CPU load is only 20%. What shall I tweak further? On Tue, Jul 12, 2005 at 02:07:38PM +0300, Danny Braniss wrote: > > > combining > > > sysctl net.inet.tcp.sendspace=131072 > > > and > > > sysctl net.inet.tcp.inflight.enable=0 > > > > > > did the trick! > > > > Congratulations! But I wonder why the throughput of FreeBSD=>Linux > > was almost equal to that of Linux=>FreeBSD. If the settings above > > improves the throughput of FreeBSD=>FreeBSD, the throughput of > > FreeBSD=>Linux would also be improved with them. Is it improved? > > > i did the sysctl on the client/sender :-) > > > > now can someone remind me what inflight does? > > > > In my understanding, it tries to estimate bandwidth-delay product and > > tries to avoid injecting too much data segments into networks. > > So, if it underestimates bandwidth-delay product, throughtput may be > > reduced. > > > > Regards, > > Noritoshi Demizu > > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
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