a546baa9cd
The meaning of the 25-14 bits in EAX returned from cpuid with EAX = 4 has been changed from "the maximum number of threads sharing the cache" to "the maximum number of addressable IDs for logical processors sharing the cache" if cpuid takes EAX = 11. We need to use results from both EAX = 4 and EAX = 11 to get the number of threads sharing the cache. The 25-14 bits in EAX on Core i7 is 15 although the number of logical processors is 8. Here is a white paper on this: http://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration/ This patch correctly counts number of logical processors on Intel CPUs with EAX = 11 support on cpuid. Tested on Dinnington, Core i7 and Nehalem EX/EP. It also fixed Pentium Ds workaround since EBX may not have the right value returned from cpuid with EAX = 1. |
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| generic | ||
| gnu | ||
| i386 | ||
| ia64 | ||
| ieee754 | ||
| mach | ||
| posix | ||
| powerpc | ||
| pthread | ||
| s390 | ||
| sh | ||
| sparc | ||
| unix | ||
| wordsize-32 | ||
| wordsize-64 | ||
| x86_64 | ||