From: Andi Kleen <[email protected]>
perf stat -rX prints the stddev for multiple measurements.
Just looking at the stddev for judging the quality of the data
is a bit dangerous The simplest sanity check is to just look
at a simple plot. This patchs add a sparkline to the end
of the measurements to make it simple to judge the data.
The sparkline only uses UTF-8, so should be readable
in all modern tools and terminals.
The sparkline is between the minimum and maximum of the data,
so it's mainly a indicator of variance. To keep the code
simple and make the output not too wide only the first
8 values are printed. If more values are there it adds '..'
The code is inspired by Zach Holman's spark shell script.
Example output (view in non-proportial font):
Performance counter stats for 'true' (10 runs):
0.175672 task-clock (msec) # 0.555 CPUs utilized ( +- 1.77% ) █▄▁▁▁▁▁▁..
0 context-switches # 0.000 K/sec
0 cpu-migrations # 0.000 K/sec
114 page-faults # 0.647 M/sec ( +- 0.14% ) ▁█▁▁████..
520,798 cycles # 2.965 GHz ( +- 1.75% ) █▄▁▁▁▁▁▁..
433,525 instructions # 0.83 insns per cycle ( +- 0.28% ) ▅▇▅▄▇█▁▆..
83,012 branches # 472.537 M/sec ( +- 0.31% ) ▅▇▆▄▇█▁▆..
3,157 branch-misses # 3.80% of all branches ( +- 2.55% ) ▇█▃▅▁▃▁▂..
0.000316660 seconds time elapsed ( +- 1.78% ) █▅▁▁▁▁▁▁..
As you can see even in the most simple run there are quite interesting
patterns. The time sparkline suggests it would be also useful to have an option
to throw the first measurement away.
Known issues:
- Makes the perf stat output wider. Could be adjust by shrinking
some white space. Not done so far.
- No output for -A/--per-socket/--per-core with -rX. This code
is missing the basic noise detection code. Once it's added there
sparklines could be shown too.
v2: Avoid printing spark lines for normal CSV case (Jiri)
Signed-off-by: Andi Kleen <[email protected]>
---
tools/perf/Makefile.perf | 1 +
tools/perf/builtin-stat.c | 12 ++++++++++++
tools/perf/util/spark.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/spark.h | 3 +++
tools/perf/util/stat.c | 33 +++++++++++++++++++++++++++++++++
tools/perf/util/stat.h | 10 ++++++++++
6 files changed, 104 insertions(+)
create mode 100644 tools/perf/util/spark.c
create mode 100644 tools/perf/util/spark.h
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 7257e7e..432d099 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -359,6 +359,7 @@ LIB_OBJS += $(OUTPUT)util/trace-event-scripting.o
LIB_OBJS += $(OUTPUT)util/trace-event.o
LIB_OBJS += $(OUTPUT)util/svghelper.o
LIB_OBJS += $(OUTPUT)util/sort.o
+LIB_OBJS += $(OUTPUT)util/spark.o
LIB_OBJS += $(OUTPUT)util/hist.o
LIB_OBJS += $(OUTPUT)util/probe-event.o
LIB_OBJS += $(OUTPUT)util/util.o
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 65a151e..cb0f7c5 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1176,6 +1176,9 @@ static void print_aggr(char *prefix)
if (run != ena)
fprintf(output, " (%.2f%%)",
100.0 * run / ena);
+
+ fputc(' ', output);
+ print_stat_spark(output, counter->priv);
}
fputc('\n', output);
}
@@ -1229,6 +1232,9 @@ static void print_counter_aggr(struct perf_evsel *counter, char *prefix)
return;
}
+ fputc(' ', output);
+ print_stat_spark(output, counter->priv);
+
if (scaled) {
double avg_enabled, avg_running;
@@ -1295,6 +1301,9 @@ static void print_counter(struct perf_evsel *counter, char *prefix)
if (run != ena)
fprintf(output, " (%.2f%%)",
100.0 * run / ena);
+
+ fputc(' ', output);
+ print_stat_spark(output, counter->priv);
}
fputc('\n', output);
}
@@ -1355,6 +1364,9 @@ static void print_stat(int argc, const char **argv)
fprintf(output, " ");
print_noise_pct(stddev_stats(&walltime_nsecs_stats),
avg_stats(&walltime_nsecs_stats));
+
+ fputc(' ', output);
+ print_stat_spark(output, &walltime_nsecs_stats);
}
fprintf(output, "\n\n");
}
diff --git a/tools/perf/util/spark.c b/tools/perf/util/spark.c
new file mode 100644
index 0000000..a677d2c
--- /dev/null
+++ b/tools/perf/util/spark.c
@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <limits.h>
+#include "spark.h"
+
+#define NUM_SPARKS 8
+#define SPARK_SHIFT 8
+
+/* Print spark lines on outf for numval values in val. */
+void print_spark(FILE *outf, unsigned long *val, int numval)
+{
+ static const char *ticks[NUM_SPARKS] = {
+ "▁", "▂", "▃", "▄", "▅", "▆", "▇", "█"
+ };
+ int i;
+ unsigned long min = LONG_MAX, max = 0, f;
+
+ for (i = 0; i < numval; i++) {
+ if (val[i] < min)
+ min = val[i];
+ if (val[i] > max)
+ max = val[i];
+ }
+ f = ((max - min) << SPARK_SHIFT) / (NUM_SPARKS - 1);
+ if (f < 1)
+ f = 1;
+ for (i = 0; i < numval; i++) {
+ fputs(ticks[((val[i] - min) << SPARK_SHIFT) / f], outf);
+ }
+}
+
+#ifdef TEST
+#include <stdlib.h>
+
+int main(int ac, char **av)
+{
+ unsigned long *val = calloc(ac - 1, sizeof(unsigned long));
+ int i;
+
+ for (i = 1; i < ac; i++)
+ val[i - 1] = strtoul(av[i], NULL, 0);
+ print_spark(stdout, val, ac - 1);
+ putchar('\n');
+ return 0;
+}
+#endif
diff --git a/tools/perf/util/spark.h b/tools/perf/util/spark.h
new file mode 100644
index 0000000..f2d5ac5
--- /dev/null
+++ b/tools/perf/util/spark.h
@@ -0,0 +1,3 @@
+#pragma once
+void print_spark(FILE *outf, unsigned long *val, int numval);
+
diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 6506b3d..2b26d74 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -1,10 +1,16 @@
#include <math.h>
+#include <stdio.h>
#include "stat.h"
+#include "spark.h"
void update_stats(struct stats *stats, u64 val)
{
double delta;
+ int n = stats->n;
+
+ if (n < NUM_SPARK_VALS)
+ stats->svals[n] = val;
stats->n++;
delta = val - stats->mean;
@@ -61,3 +67,30 @@ double rel_stddev_stats(double stddev, double avg)
return pct;
}
+
+static int all_the_same(unsigned long *vals, int len)
+{
+ int i;
+ unsigned long v0 = vals[0];
+
+ for (i = 1; i < len; i++)
+ if (vals[i] != v0)
+ return 0;
+ return 1;
+}
+
+void print_stat_spark(FILE *f, struct stats *stat)
+{
+ int n = stat->n, len;
+
+ if (n <= 1)
+ return;
+ len = n;
+ if (len > NUM_SPARK_VALS)
+ len = NUM_SPARK_VALS;
+ if (all_the_same(stat->svals, len))
+ return;
+ print_spark(f, stat->svals, len);
+ if (stat->n > NUM_SPARK_VALS)
+ fputs("..", f);
+}
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index ae8ccd7..1b4dc71 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -1,12 +1,16 @@
#ifndef __PERF_STATS_H
#define __PERF_STATS_H
+#include <stdio.h>
#include "types.h"
+#define NUM_SPARK_VALS 8 /* support spark line on first N items */
+
struct stats
{
double n, mean, M2;
u64 max, min;
+ unsigned long svals[NUM_SPARK_VALS];
};
void update_stats(struct stats *stats, u64 val);
@@ -14,12 +18,18 @@ double avg_stats(struct stats *stats);
double stddev_stats(struct stats *stats);
double rel_stddev_stats(double stddev, double avg);
+void print_stat_spark(FILE *f, struct stats *stat);
+
static inline void init_stats(struct stats *stats)
{
+ int i;
+
stats->n = 0.0;
stats->mean = 0.0;
stats->M2 = 0.0;
stats->min = (u64) -1;
stats->max = 0;
+ for (i = 0; i < NUM_SPARK_VALS; i++)
+ stats->svals[i] = 0;
}
#endif
--
1.8.5.3
Hi Andi,
On Mon, 14 Apr 2014 09:09:31 -0700, Andi Kleen wrote:
> From: Andi Kleen <[email protected]>
>
> perf stat -rX prints the stddev for multiple measurements.
> Just looking at the stddev for judging the quality of the data
> is a bit dangerous The simplest sanity check is to just look
> at a simple plot. This patchs add a sparkline to the end
> of the measurements to make it simple to judge the data.
>
> The sparkline only uses UTF-8, so should be readable
> in all modern tools and terminals.
>
> The sparkline is between the minimum and maximum of the data,
> so it's mainly a indicator of variance. To keep the code
> simple and make the output not too wide only the first
> 8 values are printed. If more values are there it adds '..'
>
> The code is inspired by Zach Holman's spark shell script.
>
> Example output (view in non-proportial font):
>
> Performance counter stats for 'true' (10 runs):
>
> 0.175672 task-clock (msec) # 0.555 CPUs utilized ( +- 1.77% ) █▄▁▁▁▁▁▁..
> 0 context-switches # 0.000 K/sec
> 0 cpu-migrations # 0.000 K/sec
> 114 page-faults # 0.647 M/sec ( +- 0.14% ) ▁█▁▁████..
> 520,798 cycles # 2.965 GHz ( +- 1.75% ) █▄▁▁▁▁▁▁..
> 433,525 instructions # 0.83 insns per cycle ( +- 0.28% ) ▅▇▅▄▇█▁▆..
> 83,012 branches # 472.537 M/sec ( +- 0.31% ) ▅▇▆▄▇█▁▆..
> 3,157 branch-misses # 3.80% of all branches ( +- 2.55% ) ▇█▃▅▁▃▁▂..
>
> 0.000316660 seconds time elapsed ( +- 1.78% ) █▅▁▁▁▁▁▁..
>
> As you can see even in the most simple run there are quite interesting
> patterns. The time sparkline suggests it would be also useful to have an option
> to throw the first measurement away.
>
> Known issues:
> - Makes the perf stat output wider. Could be adjust by shrinking
> some white space. Not done so far.
> - No output for -A/--per-socket/--per-core with -rX. This code
> is missing the basic noise detection code. Once it's added there
> sparklines could be shown too.
>
> v2: Avoid printing spark lines for normal CSV case (Jiri)
> Signed-off-by: Andi Kleen <[email protected]>
> ---
[SNIP]
> diff --git a/tools/perf/util/spark.c b/tools/perf/util/spark.c
> new file mode 100644
> index 0000000..a677d2c
> --- /dev/null
> +++ b/tools/perf/util/spark.c
> @@ -0,0 +1,45 @@
> +#include <stdio.h>
> +#include <limits.h>
> +#include "spark.h"
> +
> +#define NUM_SPARKS 8
> +#define SPARK_SHIFT 8
> +
> +/* Print spark lines on outf for numval values in val. */
> +void print_spark(FILE *outf, unsigned long *val, int numval)
> +{
> + static const char *ticks[NUM_SPARKS] = {
> + "▁", "▂", "▃", "▄", "▅", "▆", "▇", "█"
> + };
> + int i;
> + unsigned long min = LONG_MAX, max = 0, f;
s/LONG_MAX/ULONG_MAX/ ?
> +
> + for (i = 0; i < numval; i++) {
> + if (val[i] < min)
> + min = val[i];
> + if (val[i] > max)
> + max = val[i];
> + }
> + f = ((max - min) << SPARK_SHIFT) / (NUM_SPARKS - 1);
> + if (f < 1)
> + f = 1;
> + for (i = 0; i < numval; i++) {
> + fputs(ticks[((val[i] - min) << SPARK_SHIFT) / f], outf);
> + }
> +}
> +
> +#ifdef TEST
> +#include <stdlib.h>
> +
> +int main(int ac, char **av)
> +{
> + unsigned long *val = calloc(ac - 1, sizeof(unsigned long));
> + int i;
> +
> + for (i = 1; i < ac; i++)
> + val[i - 1] = strtoul(av[i], NULL, 0);
> + print_spark(stdout, val, ac - 1);
> + putchar('\n');
> + return 0;
> +}
> +#endif
Hmm.. test codes usually live in the tools/perf/tests directory.
> diff --git a/tools/perf/util/spark.h b/tools/perf/util/spark.h
> new file mode 100644
> index 0000000..f2d5ac5
> --- /dev/null
> +++ b/tools/perf/util/spark.h
> @@ -0,0 +1,3 @@
> +#pragma once
> +void print_spark(FILE *outf, unsigned long *val, int numval);
> +
> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> index 6506b3d..2b26d74 100644
> --- a/tools/perf/util/stat.c
> +++ b/tools/perf/util/stat.c
> @@ -1,10 +1,16 @@
> #include <math.h>
> +#include <stdio.h>
>
> #include "stat.h"
> +#include "spark.h"
>
> void update_stats(struct stats *stats, u64 val)
> {
> double delta;
> + int n = stats->n;
> +
> + if (n < NUM_SPARK_VALS)
> + stats->svals[n] = val;
>
> stats->n++;
> delta = val - stats->mean;
> @@ -61,3 +67,30 @@ double rel_stddev_stats(double stddev, double avg)
>
> return pct;
> }
> +
> +static int all_the_same(unsigned long *vals, int len)
> +{
> + int i;
> + unsigned long v0 = vals[0];
> +
> + for (i = 1; i < len; i++)
> + if (vals[i] != v0)
> + return 0;
> + return 1;
> +}
> +
> +void print_stat_spark(FILE *f, struct stats *stat)
> +{
> + int n = stat->n, len;
> +
> + if (n <= 1)
> + return;
> + len = n;
It seems the 'n' is not needed at all - just use 'len'.
> + if (len > NUM_SPARK_VALS)
> + len = NUM_SPARK_VALS;
> + if (all_the_same(stat->svals, len))
> + return;
Why does it skip printing if all values are same? I think you wanted to
skip the "all zero" (uncounted) case, right?
Also adding a few blank lines might improve readability a bit IMHO.
Thanks,
Namhyung
> + print_spark(f, stat->svals, len);
> + if (stat->n > NUM_SPARK_VALS)
> + fputs("..", f);
> +}
> diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
> index ae8ccd7..1b4dc71 100644
> --- a/tools/perf/util/stat.h
> +++ b/tools/perf/util/stat.h
> @@ -1,12 +1,16 @@
> #ifndef __PERF_STATS_H
> #define __PERF_STATS_H
>
> +#include <stdio.h>
> #include "types.h"
>
> +#define NUM_SPARK_VALS 8 /* support spark line on first N items */
> +
> struct stats
> {
> double n, mean, M2;
> u64 max, min;
> + unsigned long svals[NUM_SPARK_VALS];
> };
>
> void update_stats(struct stats *stats, u64 val);
> @@ -14,12 +18,18 @@ double avg_stats(struct stats *stats);
> double stddev_stats(struct stats *stats);
> double rel_stddev_stats(double stddev, double avg);
>
> +void print_stat_spark(FILE *f, struct stats *stat);
> +
> static inline void init_stats(struct stats *stats)
> {
> + int i;
> +
> stats->n = 0.0;
> stats->mean = 0.0;
> stats->M2 = 0.0;
> stats->min = (u64) -1;
> stats->max = 0;
> + for (i = 0; i < NUM_SPARK_VALS; i++)
> + stats->svals[i] = 0;
> }
> #endif
> > +void print_stat_spark(FILE *f, struct stats *stat)
> > +{
> > + int n = stat->n, len;
> > +
> > + if (n <= 1)
> > + return;
> > + len = n;
>
> It seems the 'n' is not needed at all - just use 'len'.
This would break ".." for n == NUM_SPARK_VALS
>
>
> > + if (len > NUM_SPARK_VALS)
> > + len = NUM_SPARK_VALS;
> > + if (all_the_same(stat->svals, len))
> > + return;
>
> Why does it skip printing if all values are same? I think you wanted to
> skip the "all zero" (uncounted) case, right?
A spark line is meaningless if all values are the same.
-Andi