Re: [PATCH 3/3] perf tool: give user better message if precise is not supported

[Robert Richter <robert.richter@amd.com>]

On 10.09.12 10:40:16, David Ahern wrote:
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -294,6 +294,11 @@ try_again:
>  					  perf_evsel__name(pos));
>  				rc = -err;
>  				goto out;
> +			} else if ((err == ENOTSUP) && (attr->precise_ip)) {

It is EOPNOTSUPP, did you test this?

> +				ui__error("\'precise\' request not supported. "
> +					  "Try removing 'p' modifier\n");

I would better print "... request may not be supported.", since you
don't know for sure if this is the real cause.

> +				rc = -err;
> +				goto out;
>  			}
>  
>  			printf("\n");
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 0513aaa..0d3653b 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -975,6 +975,10 @@ try_again:
>  				ui__error("Too many events are opened.\n"
>  					    "Try again after reducing the number of events\n");
>  				goto out_err;
> +			} else if ((err == ENOTSUP) && (attr->precise_ip)) {
> +				ui__error("\'precise\' request not supported. "
> +					  "Try removing 'p' modifier\n");

Same here.

> +				goto out_err;

To avoid adding more duplicate code, maybe we should start to unify
the code by implementing this in a shared helper function.

-Robert

-- 
Advanced Micro Devices, Inc.
Operating System Research Center