Re: [PATCH] perf, tools, stat: Fix perf stat -T

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Jul 27, 2015 at 04:24:51PM -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> The transaction length metrics in perf stat -T broke recently.
> It would not match the metric correctly and always print K/sec.
> This was caused by a incorrect update of the cycles_in_tx statistics.
> Update the correct variable.
> 
> Also the check for zero division was reversed, which resulted
> in K/sec being printed for no transactions. Fix this also up.
> 
> Cc: jolsa@kernel.org
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  tools/perf/util/stat-shadow.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
> index 53e8bb7..2a5d8d7 100644
> --- a/tools/perf/util/stat-shadow.c
> +++ b/tools/perf/util/stat-shadow.c
> @@ -85,7 +85,7 @@ void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 *count,
>  	else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
>  		update_stats(&runtime_cycles_stats[ctx][cpu], count[0]);
>  	else if (perf_stat_evsel__is(counter, CYCLES_IN_TX))
> -		update_stats(&runtime_transaction_stats[ctx][cpu], count[0]);
> +		update_stats(&runtime_cycles_in_tx_stats[ctx][cpu], count[0]);

oops, looks like copy&paste issue.. thanks


>  	else if (perf_stat_evsel__is(counter, TRANSACTION_START))
>  		update_stats(&runtime_transaction_stats[ctx][cpu], count[0]);
>  	else if (perf_stat_evsel__is(counter, ELISION_START))
> @@ -398,20 +398,18 @@ void perf_stat__print_shadow_stats(FILE *out, struct perf_evsel *evsel,
>  				" #   %5.2f%% aborted cycles         ",
>  				100.0 * ((total2-avg) / total));
>  	} else if (perf_stat_evsel__is(evsel, TRANSACTION_START) &&
> -		   avg > 0 &&
>  		   runtime_cycles_in_tx_stats[ctx][cpu].n != 0) {
>  		total = avg_stats(&runtime_cycles_in_tx_stats[ctx][cpu]);
>  
> -		if (total)
> +		if (avg)
>  			ratio = total / avg;
>  
>  		fprintf(out, " # %8.0f cycles / transaction   ", ratio);
>  	} else if (perf_stat_evsel__is(evsel, ELISION_START) &&
> -		   avg > 0 &&
>  		   runtime_cycles_in_tx_stats[ctx][cpu].n != 0) {
>  		total = avg_stats(&runtime_cycles_in_tx_stats[ctx][cpu]);
>  
> -		if (total)
> +		if (avg)
>  			ratio = total / avg;
>  
>  		fprintf(out, " # %8.0f cycles / elision       ", ratio);
> -- 

we now print comment line if the avg is 0, but I think it's ok

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

thanks,
jirka