Date: Sat, 13 Dec 2003 14:44:24 +0700 From: Eugene Grosbein <eugen@grosbein.pp.ru> To: Clark Gaylord <cgaylord@vt.edu> Cc: net@freebsd.org Subject: Re: how to saturate 100Mbit Message-ID: <20031213074423.GA2249@svzserv.kemerovo.su> In-Reply-To: <3FDAAC5B.5030008@vt.edu> References: <20031213054654.GA850@grosbein.pp.ru> <3FDAAC5B.5030008@vt.edu>
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On Sat, Dec 13, 2003 at 01:06:19AM -0500, Clark Gaylord wrote: > >Is it possible to saturate 100Mbit ethernet using FreeBSD 4.9-STABLE, > >Pentium-133 & Intel 430VX-based motherboard (PCI-33), > >Intel 82559 Pro/100 Ethernet (fxp) ? > >I tried to use sendfile(2) on /dev/zero but that does not work. > >Then I created 8Tb holey file and used sendfile() on it. > >That gave 100% CPU load and only 37Mbit/s on wire. > I usually use ttcp for tcp throughput measurement. You may not be able > to do 100Mbps, due to tcp-ness, but it has a udp mode as well. Depends > on what you are interested in doing. But ttcp is pretty low impact. > Also, when you use it, boost the buffersize; this can help performance > (and lower cpu hit) considerably. Will ttcp or iperf use zero-copy mechanics like sendfile(2) or they will make CPU load by copying from/to kernel space? I made another attempt: set sendspace/recvspace for TCP/UDP to 65536, mounted filesystem using NFS over UDP with -r 65536, -w 65536 and ran from NFS client: dd if=holey-file of=/dev/null bs=10m I've got about 30% of CPU load for the server (P-133) and less than 35mbit/s on wire. Eugene Grosbein
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