Date: Sat, 01 Dec 2001 08:55:42 +1030 From: Richard Sharpe <sharpe@ns.aus.com> To: Alfred Perlstein <bright@mu.org> Cc: rsharpe@ns.aus.com, Matthew Dillon <dillon@apollo.backplane.com>, Alexander Haderer <alexander.haderer@charite.de>, freebsd-hackers@FreeBSD.ORG Subject: Re: FreeBSD performing worse than Linux? Message-ID: <3C080766.5030600@ns.aus.com> References: <20011128153817.T61580@monorchid.lemis.com> <15364.38174.938500.946169@caddis.yogotech.com> <20011128104629.A43642@walton.maths.tcd.ie> <5.1.0.14.1.20011130181236.00a80160@postamt1.charite.de> <200111302047.fAUKlT811090@apollo.backplane.com> <3C07FCFF.4070008@ns.aus.com> <20011130150843.L46769@elvis.mu.org>
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Alfred Perlstein wrote: > * Richard Sharpe <sharpe@ns.aus.com> [011130 15:02] wrote: >>The traffic in the tbench case is SMB taffic. Request/response, with a >>mixture of small requests and responses, and big request/small response >>or small request/big response, where big is 64K. >> >> >>I have switched off newreno, and it made no difference. I have switched >>off delayed_ack, and it reduced performance about 5 percent. I have made >>sure that SO_SNDBUF and SO_RCVBUF were set to 131072 (which seems to be >>the max), and it increased performance marginally (like about 2%), but >>consistently. >> >>I am still analysing the packet traces I have, but it seems to me that >>the crucial difference is Linux seems to delay longer before sending >>ACKs, and thus sends less ACKs. Since the ACK is piggybacked in the >>response (or the next request), it all works fine, and the >>reponse/request gets there sooner. >> >>However, I have not convinced myself that the saving of 20uS or so per >>request/response pair accounts for some 40+ Mb/s. >> > Can you try these two commands: > > sysctl -w net.inet.tcp.recvspace=65536 > sysctl -w net.inet.tcp.sendspace=65536 Yes, that is what I did ... -- Richard Sharpe, rsharpe@ns.aus.com, LPIC-1 www.samba.org, www.ethereal.com, SAMS Teach Yourself Samba in 24 Hours, Special Edition, Using Samba To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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