Re: [PATCH 25/32] tools, perf: Add a precise event qualifier

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Nov 09, 2012 at 05:27:41PM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> Add a precise qualifier, like cpu/event=0x3c,precise=1/
> 
> This is needed so that the kernel can request enabling PEBS
> for TSX events. The parser bails out on any sysfs parse errors,
> so this is needed in any case to handle any event on the TSX
> perf kernel.
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  tools/perf/util/parse-events.c |    6 ++++++
>  tools/perf/util/parse-events.h |    1 +
>  tools/perf/util/parse-events.l |    1 +
>  3 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index c0b785b..5b97a2b 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -526,6 +526,12 @@ do {								\
>  	case PARSE_EVENTS__TERM_TYPE_NAME:
>  		CHECK_TYPE_VAL(STR);
>  		break;
> +	case PARSE_EVENTS__TERM_TYPE_PRECISE:
> +		CHECK_TYPE_VAL(NUM);
> +		if ((unsigned)term->val.num > 2)
> +			return -EINVAL;

Should we test for >3?

	* precise_ip:
	*
	*  0 - SAMPLE_IP can have arbitrary skid
	*  1 - SAMPLE_IP must have constant skid
	*  2 - SAMPLE_IP requested to have 0 skid
	*  3 - SAMPLE_IP must have 0 skid

Maybe it's not implemented in hw yet, but in general it's allowed.

thanks,
jirka