Date: Tue, 17 Mar 2009 07:14:02 -0700 (PDT) From: Won De Erick <won.derick@yahoo.com> To: freebsd-smp@FreeBSD.ORG, won.derick@yahoo.com, John Baldwin <jhb@FreeBSD.ORG>, Robert Heron <robert@heron.pl> Subject: Re: only one logical CPU used in Xeon Message-ID: <100058.54621.qm@web45803.mail.sp1.yahoo.com>
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--- On Tue, 3/17/09, Oliver Fromme <olli@lurza.secnetix.de> wrote: > won.derick@yahoo.com wrote: > > John Baldwin wrote: > > > in the ULE case (though the sysctl doesn't work). If > > > you use 4BSD on 7.1 > > > then the tunable and sysctl will work fine. > > > > > > > I tried this, but I can't see the variable being > > displayed. > > Then your machine doesn't support hyperthreading. > > The machdep.hyperthreading_allowed sysctl is only present > if your machine actually has multiple logical CPUs. > If you don't see that sysctl, then your processor doesn't > have multiple hyperthreaded CPUs. > Thanks for that further clarification. The dmesg has also justified this. #dmesg ... Cores per package: 4 ... FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs ... > If you're interested how this is done in the source, see > the > function cpu_hlt_setup() in > src/sys/amd64/amd64/mp_machdep.c > or src/sys/i386/i386/mp_machdep.c, respectively. >help
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