Re: [PATCH 7/7] perf, tools, stat: Check for frontend stalled for metrics

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Mar 01, 2016 at 10:57:52AM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> Add an extra check for frontend stalled in the metrics.
> This avoids an extra column for the --metric-only case
> when the CPU does not support frontend stalled.
> 
> v2: Add separate init function
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> ---
>  tools/perf/builtin-stat.c     | 1 +
>  tools/perf/util/stat-shadow.c | 9 ++++++++-
>  tools/perf/util/stat.h        | 1 +
>  3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 78a4205..92f6aee 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -2172,6 +2172,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
>  	argc = parse_options_subcommand(argc, argv, stat_options, stat_subcommands,
>  					(const char **) stat_usage,
>  					PARSE_OPT_STOP_AT_NON_OPTION);
> +	perf_stat__init_shadow_stats();
>  
>  	if (csv_sep) {
>  		csv_output = true;
> diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
> index 5e2d2e3..b33ffb2 100644
> --- a/tools/perf/util/stat-shadow.c
> +++ b/tools/perf/util/stat-shadow.c
> @@ -2,6 +2,7 @@
>  #include "evsel.h"
>  #include "stat.h"
>  #include "color.h"
> +#include "pmu.h"
>  
>  enum {
>  	CTX_BIT_USER	= 1 << 0,
> @@ -35,9 +36,15 @@ static struct stats runtime_dtlb_cache_stats[NUM_CTX][MAX_NR_CPUS];
>  static struct stats runtime_cycles_in_tx_stats[NUM_CTX][MAX_NR_CPUS];
>  static struct stats runtime_transaction_stats[NUM_CTX][MAX_NR_CPUS];
>  static struct stats runtime_elision_stats[NUM_CTX][MAX_NR_CPUS];
> +static bool have_frontend_stalled;
>  
>  struct stats walltime_nsecs_stats;
>  
> +void perf_stat__init_shadow_stats(void)
> +{
> +	have_frontend_stalled = pmu_have_event("cpu", "stalled-cycles-frontend");
> +}
> +
>  static int evsel_context(struct perf_evsel *evsel)
>  {
>  	int ctx = 0;
> @@ -323,7 +330,7 @@ void perf_stat__print_shadow_stats(struct perf_evsel *evsel,
>  			print_metric(ctxp, NULL, "%7.2f ",
>  					"stalled cycles per insn",
>  					ratio);
> -		} else {
> +		} else if (have_frontend_stalled) {
>  			print_metric(ctxp, NULL, NULL,
>  				     "stalled cycles per insn", 0);
>  		}
> diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
> index f02af68..0150e78 100644
> --- a/tools/perf/util/stat.h
> +++ b/tools/perf/util/stat.h
> @@ -72,6 +72,7 @@ typedef void (*print_metric_t)(void *ctx, const char *color, const char *unit,
>  			       const char *fmt, double val);
>  typedef void (*new_line_t )(void *ctx);
>  
> +void perf_stat__init_shadow_stats(void);
>  void perf_stat__reset_shadow_stats(void);
>  void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 *count,
>  				    int cpu);
> -- 
> 2.5.0
>