perf stat: Move stats related code to util/stat.c

Then, the code can be shared between kvm events and perf stat.

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
[ Dong Hao <haodong@linux.vnet.ibm.com>: rebase it on acme's git tree ]
Signed-off-by: Dong Hao <haodong@linux.vnet.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1347870675-31495-3-git-send-email-haodong@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Xiao Guangrong 2012-09-17 16:31:14 +08:00 committed by Arnaldo Carvalho de Melo
parent 034a9265c2
commit 0007eceace
4 changed files with 76 additions and 54 deletions

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@ -406,6 +406,7 @@ LIB_OBJS += $(OUTPUT)util/target.o
LIB_OBJS += $(OUTPUT)util/rblist.o
LIB_OBJS += $(OUTPUT)util/intlist.o
LIB_OBJS += $(OUTPUT)util/vdso.o
LIB_OBJS += $(OUTPUT)util/stat.o
LIB_OBJS += $(OUTPUT)ui/helpline.o
LIB_OBJS += $(OUTPUT)ui/hist.o

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@ -51,13 +51,13 @@
#include "util/evsel.h"
#include "util/debug.h"
#include "util/color.h"
#include "util/stat.h"
#include "util/header.h"
#include "util/cpumap.h"
#include "util/thread.h"
#include "util/thread_map.h"
#include <sys/prctl.h>
#include <math.h>
#include <locale.h>
#define DEFAULT_SEPARATOR " "
@ -199,11 +199,6 @@ static int output_fd;
static volatile int done = 0;
struct stats
{
double n, mean, M2;
};
struct perf_stat {
struct stats res_stats[3];
};
@ -220,50 +215,6 @@ static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
evsel->priv = NULL;
}
static void update_stats(struct stats *stats, u64 val)
{
double delta;
stats->n++;
delta = val - stats->mean;
stats->mean += delta / stats->n;
stats->M2 += delta*(val - stats->mean);
}
static double avg_stats(struct stats *stats)
{
return stats->mean;
}
/*
* http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
*
* (\Sum n_i^2) - ((\Sum n_i)^2)/n
* s^2 = -------------------------------
* n - 1
*
* http://en.wikipedia.org/wiki/Stddev
*
* The std dev of the mean is related to the std dev by:
*
* s
* s_mean = -------
* sqrt(n)
*
*/
static double stddev_stats(struct stats *stats)
{
double variance, variance_mean;
if (!stats->n)
return 0.0;
variance = stats->M2 / (stats->n - 1);
variance_mean = variance / stats->n;
return sqrt(variance_mean);
}
static struct stats runtime_nsecs_stats[MAX_NR_CPUS];
static struct stats runtime_cycles_stats[MAX_NR_CPUS];
static struct stats runtime_stalled_cycles_front_stats[MAX_NR_CPUS];
@ -559,10 +510,7 @@ static int run_perf_stat(int argc __maybe_unused, const char **argv)
static void print_noise_pct(double total, double avg)
{
double pct = 0.0;
if (avg)
pct = 100.0*total/avg;
double pct = rel_stddev_stats(total, avg);
if (csv_output)
fprintf(output, "%s%.2f%%", csv_sep, pct);

57
tools/perf/util/stat.c Normal file
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@ -0,0 +1,57 @@
#include <math.h>
#include "stat.h"
void update_stats(struct stats *stats, u64 val)
{
double delta;
stats->n++;
delta = val - stats->mean;
stats->mean += delta / stats->n;
stats->M2 += delta*(val - stats->mean);
}
double avg_stats(struct stats *stats)
{
return stats->mean;
}
/*
* http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
*
* (\Sum n_i^2) - ((\Sum n_i)^2)/n
* s^2 = -------------------------------
* n - 1
*
* http://en.wikipedia.org/wiki/Stddev
*
* The std dev of the mean is related to the std dev by:
*
* s
* s_mean = -------
* sqrt(n)
*
*/
double stddev_stats(struct stats *stats)
{
double variance, variance_mean;
if (!stats->n)
return 0.0;
variance = stats->M2 / (stats->n - 1);
variance_mean = variance / stats->n;
return sqrt(variance_mean);
}
double rel_stddev_stats(double stddev, double avg)
{
double pct = 0.0;
if (avg)
pct = 100.0 * stddev/avg;
return pct;
}

16
tools/perf/util/stat.h Normal file
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@ -0,0 +1,16 @@
#ifndef __PERF_STATS_H
#define __PERF_STATS_H
#include "types.h"
struct stats
{
double n, mean, M2;
};
void update_stats(struct stats *stats, u64 val);
double avg_stats(struct stats *stats);
double stddev_stats(struct stats *stats);
double rel_stddev_stats(double stddev, double avg);
#endif