Re: [PATCH] perf tools: fix guest mode monitoring on AMD

[Gleb Natapov <gleb@redhat.com>]

On Mon, Feb 27, 2012 at 06:33:51PM +0100, Stephane Eranian wrote:
> Commit:
> 
> 1aed267 perf kvm: Do guest-only counting by default
>  
> introduced a bug on AMD systems whereby simple commands:
> 
> $ perf stat ls
> Performance counter stats for 'ls':
>                  0 cycles                    #    0.000 GHz                    
>        0.003704596 seconds time elapsed
> 
> would not count anything anymore. Same results for perf record.
> 
> I tracked it down to guest mode exclusion being enabled
> by default leading to attr->exclude_guest = 1. When
> not operating under any sort of virtualization, this
> causes the PMU not to count anything.
CCing Joerg. I think he fixed this or similar problem recently.

> 
> The fix disables guest exclusion by default.
> 
> Signed-off-by: Stephane Eranian <eranian@google.com>
> ---
> 
> diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> index 8109a90..c1017b3 100644
> --- a/tools/perf/util/util.c
> +++ b/tools/perf/util/util.c
> @@ -6,7 +6,7 @@
>   * XXX We need to find a better place for these things...
>   */
>  bool perf_host  = true;
> -bool perf_guest = false;
> +bool perf_guest = true;
>  
>  void event_attr_init(struct perf_event_attr *attr)
>  {

--
			Gleb.