Re: [PATCH] perf/x86/intel/pt: Export cpu frequency ratios needed by PT decoders

On Mon, Aug 31, 2015 at 03:59:08PM +0300, Alexander Shishkin wrote: > Andi Kleen writes: > > > Alexander Shishkin writes: > >> + return sprintf(page, "%lu\n", val); > >> + case 1: > >> + cpuid(0x15, &eax, &ebx, &ecx, &edx); > > > > Surely this needs to be protected by a cpuid

Re: [PATCH] perf/x86/intel/pt: Export cpu frequency ratios needed by PT decoders

Andi Kleen writes: > Alexander Shishkin writes: >> +return sprintf(page, "%lu\n", val); >> +case 1: >> +cpuid(0x15, &eax, &ebx, &ecx, &edx); > > Surely this needs to be protected by a cpuid level check? > Broadwell for once doesn't have CPUID 0x15. I couldn't find wh

Re: [PATCH] perf/x86/intel/pt: Export cpu frequency ratios needed by PT decoders

Alexander Shishkin writes: > + return sprintf(page, "%lu\n", val); > + case 1: > + cpuid(0x15, &eax, &ebx, &ecx, &edx); Surely this needs to be protected by a cpuid level check? Broadwell for once doesn't have CPUID 0x15. -Andi -- a...@linux.intel.com -- Speaking fo

[PATCH] perf/x86/intel/pt: Export cpu frequency ratios needed by PT decoders

In order for Intel PT decoders to infer correct crystal clock and bus frequencies that are required to correctly decode timing information from a PT stream (MTC and CBR packets), export them as sysfs attributes: * max_nonturbo_ratio: ratio between the invariant TSC and base clock; * tsc_art_ra