Date: Mon, 20 Aug 2007 14:08:58 -0700 From: "Kevin Oberman" <oberman@es.net> To: net@freebsd.org Cc: andre@networx.ch Subject: Unable to set socket size > 16MB Message-ID: <20070820210858.326AE4506A@ptavv.es.net>
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--==_Exmh_1187644138_93167P Content-Type: text/plain; charset=us-ascii Content-Disposition: inline I am trying to tune a FreeBSD system for ~100 ms. RTT at 10 Gbps. (I posted another message about this back on 8/17). I am running current of late July 31. I am using iperf and I have confirmed (with gdb) that it is passing setsockopt a size of 67108864 and setsockopt is returning 0. When I capture the SYN packets, I am seeing a window of 64K and a scale factor of 8. For 64 MB, the scale factor should be 10. Is there some hidden limitation that would restrict this or is there a bug involved? I have set net.inet.tcp.(send|recv)space to 64m. kern.ipc.maxsockbuf=134217728. Here is the 3-way handshake: 13:57:45.571614 IP lbl.52460 > perf-bnl.commplex-link: S 4070670678:4070670678(0) win 65535 <mss 8960,nop,wscale 8,sackOK,timestamp 345761341 0> 13:57:45.665645 IP perf-bnl.commplex-link > lbl.52460: S 3909263475:3909263475(0) ack 4070670679 win 65535 <mss 8960,nop,wscale 8,nop,nop,timestamp 3623078172 345761341> 13:57:45.665683 IP lbl.52460 > perf-bnl.commplex-link: . ack 1 win 65535 <nop,nop,timestamp 345761435 3623078172> Any reason for this? Any workaround or fix? Or am I missing something? -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751 --==_Exmh_1187644138_93167P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) Comment: Exmh version 2.5 06/03/2002 iD8DBQFGygLqkn3rs5h7N1ERAvZCAJ91VskviFrSx8/gzotJauX1QHhV8gCeMv6v +EeYwYXLmnA/y7ofsCB1odE= =lrH3 -----END PGP SIGNATURE----- --==_Exmh_1187644138_93167P--
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