Re: [PATCH 7/8] perf tools: Check fallback error and order

[Ravi Bangoria]

> @@ -2366,9 +2403,6 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
>  	return 0;
>  
>  try_fallback:
> -	if (evsel__precise_ip_fallback(evsel))
> -		goto retry_open;
> -
>  	if (evsel__ignore_missing_thread(evsel, perf_cpu_map__nr(cpus),
>  					 idx, threads, thread, err)) {
>  		/* We just removed 1 thread, so lower the upper nthreads limit. */
> @@ -2385,11 +2419,15 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
>  	if (err == -EMFILE && rlimit__increase_nofile(&set_rlimit))
>  		goto retry_open;
>  
> -	if (err != -EINVAL || idx > 0 || thread > 0)
> -		goto out_close;
> +	if (err == -EOPNOTSUPP && evsel__precise_ip_fallback(evsel))
> +		goto retry_open;

This will change the behavior of events like instructions:P on AMD.

Without patch:
  $ ./perf record -e instructions:P -- true
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.009 MB perf.data (9 samples) ]

With the patch:

  $ ./perf record -e instructions:P -- true
  Error:
  The instructions:Pu event is not supported.

Thanks,
Ravi