Date: Mon, 7 Nov 2005 11:16:19 -1000 From: Robert Marella <rmarella@gmail.com> To: Roland Smith <rsmith@xs4all.nl> Cc: freebsd-questions@freebsd.org, jwl@io.dk Subject: Re: enable smp / hyperthreading Message-ID: <20051107111619.108a3ae3@frankie.konav201.local> In-Reply-To: <20051107190524.GA77411@slackbox.xs4all.nl> References: <20051107185226.M70218@io.dk> <20051107190524.GA77411@slackbox.xs4all.nl>
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On Mon, 7 Nov 2005 20:05:24 +0100 Roland Smith <rsmith@xs4all.nl> wrote: > On Mon, Nov 07, 2005 at 07:53:20PM +0100, jwl@io.dk wrote: > > Hi > > > > I've just installed 6.0-RELASE and am trying to get SMP to work (I > > have af Pentium 4 with HT). So I've compiled the kernel with > > 'options SMP' and according to dmesg the two CPUs are found: > > > > FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs > > cpu0 (BSP): APIC ID: 0 > > cpu1 (AP): APIC ID: 1 > > > > But I'm not sure that both are enabled, because at this is at the > > end of dmesg and I dont see the other CPU being enabled somewhere: > > > > SMP: AP CPU #1 Launched! > > I think it is referring to the Auxiliary Processor (AP), because the > BSP (don't know what that stands for, though) is obviously already > active. > > According to 'sysctl -a' there are 2 CPUs, but only 1 active and SMP > > doesnt seem to be disabled: > > > > kern.smp.cpus: 2 > > kern.smp.disabled: 0 > > kern.smp.active: 1 > > sysctl -d kern.smp.active > kern.smp.active: Number of Auxillary Processors (APs) that were > successfully started > > This is the number of _extra_ CPUs, which chould be 1. > > Roland If hyperthreading is working the ouput of 'top' should have a C column and will show either a 0 or a 1. AFAIK HTT is still disabled because of a security risk. See: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:09.htt.asc If you do not believe you are at risk, there is a work around included in the above site. YMMV. I have been known to be wrong before. :-) Robert
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