How would you generically detect cache line associativity from user mode code?

Question

I\'m putting together a small patch for the cachegrind/callgrind tool in valgrind which will auto-detect, using completely generic code, CPU instruction and cache configuration

Answer 1

For x86 platform you can use cpuid:

See http://www.intel.com/content/www/us/en/processors/processor-identification-cpuid-instruction-note.html for details.

You need something like:

long _eax,_ebx,_ecx,_edx;
long op = func;

asm ("cpuid"
    : "=a" (_eax),
    "=b" (_ebx),
    "=c" (_ecx),
    "=d" (_edx)
    : "a" (op)
);

Then use the info according to the doc in the link mentioned above.