Re: [PATCH 01/29] x86: perfcounter: remove X86_FEATURE_ARCH_PERFMON flag for AMD cpus

Ingo Molnar
2009-04-29T11:22:27Z

* Robert Richter <robert.richter@amd.com> wrote:

> X86_FEATURE_ARCH_PERFMON is an Intel hardware feature that does not
> work on AMD CPUs. The flag is now only used in Intel specific code
> (especially initialization).
>
> Signed-off-by: Robert Richter <robert.richter@amd.com>
> ---
> arch/x86/kernel/cpu/amd.c | 4 ----
> arch/x86/kernel/cpu/perf_counter.c | 6 +++---
> 2 files changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index fd69c51..7e4a459 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -420,10 +420,6 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
> if (c->x86 >= 6)
> set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
>
> - /* Enable Performance counter for K7 and later */
> - if (c->x86 > 6 && c->x86 <= 0x11)
> - set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);

might make sense to introduce a 'virtual CPU ID flag' for it like we
do it in other cases, to signal that we support perfcounters on this
CPU.

Ingo