Messages in this thread | | | From | YhLu <> | Subject | RE: 2.6.12-rc5 is broken in nvidia Ck804 Opteron MB/with dual cor e dual way | Date | Thu, 2 Jun 2005 14:15:55 -0700 |
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in detect_ht if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY)) return;
cpu_has(c, X86_FEATURE_CMP_LEGACY) for AMD is 1, so smp_num_siblings is not changed and it is still initial value. (1)....
YH
> -----Original Message----- > From: YhLu > Sent: Thursday, June 02, 2005 1:42 PM > To: Ashok Raj > Cc: Andi Kleen; linux-kernel@vger.kernel.org > Subject: RE: 2.6.12-rc5 is broken in nvidia Ck804 Opteron > MB/with dual cor e dual way > > cpuid(1, &eax, &ebx, &ecx, &edx); > smp_num_siblings = (ebx & 0xff0000) >> 16; > > For amd dual core, smp_num_siblings is set to 1, and it mean > has two cores. > > seq_printf(m, "siblings\t: %d\n", > c->x86_num_cores * smp_num_siblings); > > for Intel it would be > c->x86_num_cores is 2 and smp_num_siblings is 2 too.... > so every core will be HT.... > > > Function 0000_0001[EBX] > EBX[23:16] Logical Processor Count. If CPUID Fn[8000_0001, > 0000_0001][EDX: > HTT, ECX: > CMPLegacy] = 11b, then this field indicates the number of CPU > cores in the processor. > Otherwise, this field is reserved. > > what is intel value about cpuid(1) ebx [23:16], when the CPU > is dual core, but HT is disabled. > 1? > > YH > > > -----Original Message----- > > From: Ashok Raj [mailto:ashok.raj@intel.com] > > Sent: Thursday, June 02, 2005 12:07 PM > > To: YhLu > > Cc: Andi Kleen; linux-kernel@vger.kernel.org > > Subject: Re: 2.6.12-rc5 is broken in nvidia Ck804 Opteron > MB/with dual > > cor e dual way > > > > On Thu, Jun 02, 2005 at 11:56:25AM -0700, YhLu wrote: > > > > > > Really?, smp_num_siblings is global variable and > > initially is set 1. > > > > > > YH > > > > > But detect_ht() can override it.. thats just the start value. > > > > try cscope :-) > > > > Cheers, > > ashok > > > - > To unsubscribe from this list: send the line "unsubscribe > linux-kernel" in the body of a message to > majordomo@vger.kernel.org More majordomo info at > http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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