Re: SMP kernel, only single processor appears (fwd)

[Zwane Mwaikambo]

On Thu, 15 Jan 2004, Zwane Mwaikambo wrote:

> On Thu, 15 Jan 2004, Gaspar Bakos wrote:
> >
> > I have an Intel 7505VB2 dual Xeon motherboard with 2x2.66GHz CPUs, Redhat
> > 9.0 and self-compiled 2.4.23 kernel. Interestingly, I see only one CPU
> > with e.g. "top", or cat /proc/cpuinfo, etc.
> >
> > I have to tell though that I installed this system by cloning the disk of
> > another PC, which is running a single processor; then booting in the dual
> > processor computer from the cloned disk (with a bootfloppy), and then
> > recompiling the kernel (and rebooting to the new SMP enabled kernel).
> > Seems to me that this is not enough, and I might have missed something.
> >
> > Any advice would be welcome.
>
> This looks like you have 2 physical processors. Perhaps you don't have
> hyperthreading enabled, i presume you want 4 logical processors. Try the
> "acpi=ht" kernel parameter.

Sorry i mis-parsed your email in my haste. Could you try the following
patch (Courtesy of Peter Breitenlohner)

--- linux-2.4.23/include/asm-i386/smpboot.h.orig	2003-08-25 13:44:43.000000000 +0200
+++ linux-2.4.23/include/asm-i386/smpboot.h	2003-12-02 16:49:46.000000000 +0100
@@ -73,11 +73,9 @@
  */
 static inline int cpu_present_to_apicid(int mps_cpu)
 {
-	if (clustered_apic_mode == CLUSTERED_APIC_XAPIC)
-		return raw_phys_apicid[mps_cpu];
 	if(clustered_apic_mode == CLUSTERED_APIC_NUMAQ)
 		return (mps_cpu/4)*16 + (1<<(mps_cpu%4));
-	return mps_cpu;
+	return raw_phys_apicid[mps_cpu];
 }

 static inline unsigned long apicid_to_phys_cpu_present(int apicid)
-
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