Date: Mon, 27 Sep 2004 20:58:31 +0300 From: Petri Helenius <pete@he.iki.fi> To: mre2007@cs.columbia.edu Cc: Dave Dolson <ddolson@sandvine.com> Subject: Re: "Kernel Hacking"/Developing on a HT CPU versus "physical" CPUs Message-ID: <415854C7.4040502@he.iki.fi> In-Reply-To: <15450.148.104.5.33.1096302710.squirrel@webmail.cs.columbia.edu> References: <A8535F8D62F3644997E91F4F66E341FC4063EC@exchange.sandvine.com> <15450.148.104.5.33.1096302710.squirrel@webmail.cs.columbia.edu>
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mre2007@cs.columbia.edu wrote: >Dave: > >yes this makes sense! So, does the scheduler take this into consideration? > > > The _ULE scheduler does, the _4BSD scheduler does not. Pete >-Marc > > > >>Here is one example: >>If you have dual HT processors, this looks like 4 CPUs to the O/S. >>For performance reasons, the scheduler should not treat them equally. >>If there are two threads to run, they should be put on different physical >>processors (vs. two hyperthreads of the same processor). >> >> >>David Dolson (ddolson@sandvine.com, www.sandvine.com) >> >> >> >> >>>-----Original Message----- >>>From: owner-freebsd-smp@freebsd.org >>>[mailto:owner-freebsd-smp@freebsd.org]On Behalf Of >>>mre2007@cs.columbia.edu >>>Sent: Saturday, September 25, 2004 10:48 AM >>>To: freebsd-smp@freebsd.org >>>Subject: "Kernel Hacking"/Developing on a HT CPU versus >>>"physical" CPUs >>> >>> >>>Hey, I was wondering if from a developing/"kernel hacking" >>>standpoint, are >>>hyperthreading and two "physical" CPUs any different? At what >>>point do the >>>differences have to be taken into consideration when working on the >>>FreeBSD kernel/scheduler/etc? I'm looking to start contributing to the >>>FreeBSD project and am trying to get some hardware set aside. >>> >>>Thanks! >>>-Marc >>>_______________________________________________ >>>freebsd-smp@freebsd.org mailing list >>>http://lists.freebsd.org/mailman/listinfo/freebsd-smp >>>To unsubscribe, send any mail to "freebsd-smp-unsubscribe@freebsd.org" >>> >>> >>> >_______________________________________________ >freebsd-smp@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-smp >To unsubscribe, send any mail to "freebsd-smp-unsubscribe@freebsd.org" > >home | help
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