Date: Thu, 11 Jul 2002 16:25:40 -0700 From: David Schultz <dschultz@uclink.Berkeley.EDU> To: Thierry Herbelot <thierry@herbelot.com> Cc: Matthew Dillon <dillon@apollo.backplane.com>, freebsd-stable@FreeBSD.ORG Subject: Re: tuning(7) request was: Re: Performance boost with kernel options in FBSD 4.6 Message-ID: <20020711232540.GA1437@HAL9000.wox.org> In-Reply-To: <3D2DF09C.B553DE07@herbelot.com> References: <20020710104730.L10343-100000@klima.physik.uni-mainz.de> <04a601c228dc$c6dbb980$681663cf@icarz.com> <200207111930.g6BJUX5m096974@apollo.backplane.com> <3D2DF09C.B553DE07@herbelot.com>
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Thus spake Thierry Herbelot <thierry@herbelot.com>: > Matthew Dillon wrote: > > > > An increased switching rate (increasing HZ) may be useful in the above > > situation. Still, I would not recommend increasing Hz above 500 (2ms). > > 10000 (100uS) is just plain insane. > > > > from actual experience, any p-III with a clock rate above 500MHz (that > is, any recent CPU) can sustain Hz=5000, which I used to run > trafific-shaped packet blasters (admittedly a narrow focus ...) with > very good results (better than special-purpose test boxes). > > As is said in the dummynet man page, FreeBSD can be a very good traffic > shaper, if the userland scheduling rate is high enough (will it be the > same with threads in -current, with KSE ?). Sure modern processors can handle 5000 Hz at the expense of a few CPU cycles, but do you actually find that dummynet isn't accurate enough at 1000 Hz? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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