Date: Mon, 10 Mar 2003 13:44:51 -0500 (EST) From: John Baldwin <jhb@FreeBSD.org> To: Richard Nyberg <rnyberg@it.su.se> Cc: freebsd-smp@FreeBSD.org Subject: Re: hyperthreading randomness Message-ID: <XFMail.20030310134451.jhb@FreeBSD.org> In-Reply-To: <20030310182918.GA32085@murmeldjur.it.su.se>
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On 10-Mar-2003 Richard Nyberg wrote: > On Mon, Mar 10, 2003 at 01:00:13PM -0500, John Baldwin wrote: >> >> On 08-Mar-2003 Richard Nyberg wrote: >> > I have a Dell Precision 450 with 2 xeon CPU:s. >> > The weird thing is that it randomly boots up >> > with either 2 or 4 CPUs on the same 4-STABLE kernel. >> > 2 more often than 4. It seems a bit unpredictable :( >> >> Hmm, I have no idea about that one. Hmm, it seems to be a >> "feature" of the BIOS perhaps. It seems that it may be listing >> the second CPU with an APIC ID of 3 (it's second core) instead >> of 2 (it's first core) in which case the HTT code sees that >> something is not right and doesn't start up any extra processors. >> > > I see. > > Do you think this quirk will cause trouble when FreeBSD gets its > CPU info from ACPI? No. With ACPI the BIOS tells us all the CPUs and we don't have to guess at the existence of any CPUs. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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