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

From: Jiri Olsa
Date: Wed Nov 28 2012 - 10:40:47 EST


On Fri, Nov 09, 2012 at 05:27:41PM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxx>
> ---
> 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
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