Re: [PATCH 2/2] perf tools: Improve IBS error handling

Jiri Olsa
2021-10-07T17:28:42Z

On Mon, Oct 04, 2021 at 04:41:14PM -0500, Kim Phillips wrote:

SNIP

> ---
> tools/perf/util/evsel.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index b915840690d4..f8a9cbd99314 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2743,9 +2743,22 @@ static bool find_process(const char *name)
> return ret ? false : true;
> }
>
> +static bool is_amd(const char *arch, const char *cpuid)
> +{
> + return arch && !strcmp("x86", arch) && cpuid && strstarts(cpuid, "AuthenticAMD");
> +}
> +
> +static bool is_amd_ibs(struct evsel *evsel)
> +{
> + return evsel->core.attr.precise_ip || !strncmp(evsel->pmu_name, "ibs", 3);
> +}
> +
> int evsel__open_strerror(struct evsel *evsel, struct target *target,
> int err, char *msg, size_t size)
> {
> + struct perf_env *env = evsel__env(evsel);
> + const char *arch = perf_env__arch(env);
> + const char *cpuid = perf_env__cpuid(env);
> char sbuf[STRERR_BUFSIZE];
> int printed = 0, enforced = 0;
>
> @@ -2841,6 +2854,17 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
> return scnprintf(msg, size, "wrong clockid (%d).", clockid);
> if (perf_missing_features.aux_output)
> return scnprintf(msg, size, "The 'aux_output' feature is not supported, update the kernel.");
> + if (is_amd(arch, cpuid)) {
> + if (is_amd_ibs(evsel)) {

would single 'is_amd_ibs' call be better? checking on both amd and ibs

jirka

> + if (evsel->core.attr.exclude_kernel)
> + return scnprintf(msg, size,
> + "AMD IBS can't exclude kernel events. Try running at a higher privilege level.");
> + if (!evsel->core.system_wide)
> + return scnprintf(msg, size,
> + "AMD IBS may only be available in system-wide/per-cpu mode. Try using -a, or -C and workload affinity");
> + }
> + }
> +
> break;
> case ENODATA:
> return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. "
> --
> 2.31.1
>