Date: Fri, 31 Jan 2003 13:24:10 -0800 (PST) From: Julian Elischer <julian@elischer.org> To: John Baldwin <jhb@FreeBSD.org> Cc: Matthew Dillon <dillon@apollo.backplane.com>, Matthew Dillon <dillon@apollo.backplane.com>, Trish Lynch <trish@bsdunix.net>, freebsd-current@FreeBSD.ORG, "Daniel C. Sobral" <dcs@tcoip.com.br> Subject: Re: Hyperthreading and machdep.cpu_idle_hlt Message-ID: <Pine.BSF.4.21.0301311323310.45015-100000@InterJet.elischer.org> In-Reply-To: <XFMail.20030131155900.jhb@FreeBSD.org>
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On Fri, 31 Jan 2003, John Baldwin wrote: > > On 31-Jan-2003 Julian Elischer wrote: > > > > > > On Fri, 31 Jan 2003, John Baldwin wrote: > > > >> >> AT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,<b28>,ACC> > >> >> > >> >> It has HTT set but it's only a 1.2GHz box and I heard somewhere that only > >> >> 2+ GHz P4's had hyperthreading. I noticed some MFCs to stable that > >> >> suggested hyperthreading support but I do not know if full hyperthreading > >> >> support has been MFCd yet or is intended to be MFCd to -stable. > >> > > >> > AFAIK, full hyperthreading support, as it is, has been merged to > >> > -stable. It consists of a patch to recognize the virtual CPUs, so they > >> > will be dealt with like any SMP system, as long as HTT is enabled on the > >> > BIOS. > >> > >> Well, sort of. We have no way of knowing if it is off in the BIOS unless > >> we use the ACPI tables to enumerate CPU's (which we don't), so turning it > >> off in the BIOS won't turn it off in FreeBSD for the time being. :) > >> > > I have a 2,8GHz p4 here which has HTT and has a bios option for > > > > Interrupt mode: [APIC/PIC] > > > > I'm using APIC mode but an SMP (today's 4.x) kernel > > panics imediatly saying it can;t find an APIC. > > You need to have an mptable for it to work. The mptable will > only list one processor, but it still needs to be there. if that comes from the BIOS, can it be simulated for uniprocessor machines with HTT? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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