perf: Rename perf-examples.txt to examples.txt
[safe/jmp/linux-2.6] / tools / perf / builtin-stat.c
index c43e4a9..b4b06c7 100644 (file)
@@ -32,6 +32,7 @@
  *   Wu Fengguang <fengguang.wu@intel.com>
  *   Mike Galbraith <efault@gmx.de>
  *   Paul Mackerras <paulus@samba.org>
+ *   Jaswinder Singh Rajput <jaswinder@kernel.org>
  *
  * Released under the GPL v2. (and only v2, not any later version)
  */
@@ -43,8 +44,9 @@
 #include "util/parse-events.h"
 
 #include <sys/prctl.h>
+#include <math.h>
 
-static struct perf_counter_attr default_attrs[MAX_COUNTERS] = {
+static struct perf_counter_attr default_attrs[] = {
 
   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK     },
   { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES},
@@ -58,35 +60,50 @@ static struct perf_counter_attr default_attrs[MAX_COUNTERS] = {
 
 };
 
+#define MAX_RUN                        100
+
 static int                     system_wide                     =  0;
-static int                     inherit                         =  1;
 static int                     verbose                         =  0;
+static unsigned int            nr_cpus                         =  0;
+static int                     run_idx                         =  0;
+
+static int                     run_count                       =  1;
+static int                     inherit                         =  1;
+static int                     scale                           =  1;
+static int                     target_pid                      = -1;
+static int                     null_run                        =  0;
 
 static int                     fd[MAX_NR_CPUS][MAX_COUNTERS];
 
-static int                     target_pid                      = -1;
-static int                     nr_cpus                         =  0;
-static unsigned int            page_size;
+static u64                     runtime_nsecs[MAX_RUN];
+static u64                     walltime_nsecs[MAX_RUN];
+static u64                     runtime_cycles[MAX_RUN];
 
-static int                     scale                           =  1;
+static u64                     event_res[MAX_RUN][MAX_COUNTERS][3];
+static u64                     event_scaled[MAX_RUN][MAX_COUNTERS];
 
-static const unsigned int default_count[] = {
-       1000000,
-       1000000,
-         10000,
-         10000,
-       1000000,
-         10000,
-};
+static u64                     event_res_avg[MAX_COUNTERS][3];
+static u64                     event_res_noise[MAX_COUNTERS][3];
+
+static u64                     event_scaled_avg[MAX_COUNTERS];
+
+static u64                     runtime_nsecs_avg;
+static u64                     runtime_nsecs_noise;
+
+static u64                     walltime_nsecs_avg;
+static u64                     walltime_nsecs_noise;
 
-static __u64                   event_res[MAX_COUNTERS][3];
-static __u64                   event_scaled[MAX_COUNTERS];
+static u64                     runtime_cycles_avg;
+static u64                     runtime_cycles_noise;
 
-static __u64                   runtime_nsecs;
-static __u64                   walltime_nsecs;
-static __u64                   runtime_cycles;
+#define MATCH_EVENT(t, c, counter)                     \
+       (attrs[counter].type == PERF_TYPE_##t &&        \
+        attrs[counter].config == PERF_COUNT_##c)
 
-static void create_perf_stat_counter(int counter)
+#define ERR_PERF_OPEN \
+"Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n"
+
+static void create_perf_stat_counter(int counter, int pid)
 {
        struct perf_counter_attr *attr = attrs + counter;
 
@@ -95,21 +112,23 @@ static void create_perf_stat_counter(int counter)
                                    PERF_FORMAT_TOTAL_TIME_RUNNING;
 
        if (system_wide) {
-               int cpu;
-               for (cpu = 0; cpu < nr_cpus; cpu ++) {
+               unsigned int cpu;
+
+               for (cpu = 0; cpu < nr_cpus; cpu++) {
                        fd[cpu][counter] = sys_perf_counter_open(attr, -1, cpu, -1, 0);
-                       if (fd[cpu][counter] < 0 && verbose) {
-                               printf("Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n", counter, fd[cpu][counter], strerror(errno));
-                       }
+                       if (fd[cpu][counter] < 0 && verbose)
+                               fprintf(stderr, ERR_PERF_OPEN, counter,
+                                       fd[cpu][counter], strerror(errno));
                }
        } else {
-               attr->inherit   = inherit;
-               attr->disabled  = 1;
-
-               fd[0][counter] = sys_perf_counter_open(attr, 0, -1, -1, 0);
-               if (fd[0][counter] < 0 && verbose) {
-                       printf("Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n", counter, fd[0][counter], strerror(errno));
-               }
+               attr->inherit        = inherit;
+               attr->disabled       = 1;
+               attr->enable_on_exec = 1;
+
+               fd[0][counter] = sys_perf_counter_open(attr, pid, -1, -1, 0);
+               if (fd[0][counter] < 0 && verbose)
+                       fprintf(stderr, ERR_PERF_OPEN, counter,
+                               fd[0][counter], strerror(errno));
        }
 }
 
@@ -118,13 +137,8 @@ static void create_perf_stat_counter(int counter)
  */
 static inline int nsec_counter(int counter)
 {
-       if (attrs[counter].type != PERF_TYPE_SOFTWARE)
-               return 0;
-
-       if (attrs[counter].config == PERF_COUNT_SW_CPU_CLOCK)
-               return 1;
-
-       if (attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK)
+       if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
+           MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
                return 1;
 
        return 0;
@@ -135,22 +149,25 @@ static inline int nsec_counter(int counter)
  */
 static void read_counter(int counter)
 {
-       __u64 *count, single_count[3];
-       ssize_t res;
-       int cpu, nv;
+       u64 *count, single_count[3];
+       unsigned int cpu;
+       size_t res, nv;
        int scaled;
 
-       count = event_res[counter];
+       count = event_res[run_idx][counter];
 
        count[0] = count[1] = count[2] = 0;
 
        nv = scale ? 3 : 1;
-       for (cpu = 0; cpu < nr_cpus; cpu ++) {
+       for (cpu = 0; cpu < nr_cpus; cpu++) {
                if (fd[cpu][counter] < 0)
                        continue;
 
-               res = read(fd[cpu][counter], single_count, nv * sizeof(__u64));
-               assert(res == nv * sizeof(__u64));
+               res = read(fd[cpu][counter], single_count, nv * sizeof(u64));
+               assert(res == nv * sizeof(u64));
+
+               close(fd[cpu][counter]);
+               fd[cpu][counter] = -1;
 
                count[0] += single_count[0];
                if (scale) {
@@ -162,13 +179,13 @@ static void read_counter(int counter)
        scaled = 0;
        if (scale) {
                if (count[2] == 0) {
-                       event_scaled[counter] = -1;
+                       event_scaled[run_idx][counter] = -1;
                        count[0] = 0;
                        return;
                }
 
                if (count[2] < count[1]) {
-                       event_scaled[counter] = 1;
+                       event_scaled[run_idx][counter] = 1;
                        count[0] = (unsigned long long)
                                ((double)count[0] * count[1] / count[2] + 0.5);
                }
@@ -176,12 +193,127 @@ static void read_counter(int counter)
        /*
         * Save the full runtime - to allow normalization during printout:
         */
-       if (attrs[counter].type == PERF_TYPE_SOFTWARE &&
-               attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK)
-               runtime_nsecs = count[0];
-       if (attrs[counter].type == PERF_TYPE_HARDWARE &&
-               attrs[counter].config == PERF_COUNT_HW_CPU_CYCLES)
-               runtime_cycles = count[0];
+       if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
+               runtime_nsecs[run_idx] = count[0];
+       if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
+               runtime_cycles[run_idx] = count[0];
+}
+
+static int run_perf_stat(int argc __used, const char **argv)
+{
+       unsigned long long t0, t1;
+       int status = 0;
+       int counter;
+       int pid;
+       int child_ready_pipe[2], go_pipe[2];
+       char buf;
+
+       if (!system_wide)
+               nr_cpus = 1;
+
+       if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) {
+               perror("failed to create pipes");
+               exit(1);
+       }
+
+       if ((pid = fork()) < 0)
+               perror("failed to fork");
+
+       if (!pid) {
+               close(child_ready_pipe[0]);
+               close(go_pipe[1]);
+               fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
+
+               /*
+                * Do a dummy execvp to get the PLT entry resolved,
+                * so we avoid the resolver overhead on the real
+                * execvp call.
+                */
+               execvp("", (char **)argv);
+
+               /*
+                * Tell the parent we're ready to go
+                */
+               close(child_ready_pipe[1]);
+
+               /*
+                * Wait until the parent tells us to go.
+                */
+               if (read(go_pipe[0], &buf, 1) == -1)
+                       perror("unable to read pipe");
+
+               execvp(argv[0], (char **)argv);
+
+               perror(argv[0]);
+               exit(-1);
+       }
+
+       /*
+        * Wait for the child to be ready to exec.
+        */
+       close(child_ready_pipe[1]);
+       close(go_pipe[0]);
+       if (read(child_ready_pipe[0], &buf, 1) == -1)
+               perror("unable to read pipe");
+       close(child_ready_pipe[0]);
+
+       for (counter = 0; counter < nr_counters; counter++)
+               create_perf_stat_counter(counter, pid);
+
+       /*
+        * Enable counters and exec the command:
+        */
+       t0 = rdclock();
+
+       close(go_pipe[1]);
+       wait(&status);
+
+       t1 = rdclock();
+
+       walltime_nsecs[run_idx] = t1 - t0;
+
+       for (counter = 0; counter < nr_counters; counter++)
+               read_counter(counter);
+
+       return WEXITSTATUS(status);
+}
+
+static void print_noise(u64 *count, u64 *noise)
+{
+       if (run_count > 1)
+               fprintf(stderr, "   ( +- %7.3f%% )",
+                       (double)noise[0]/(count[0]+1)*100.0);
+}
+
+static void nsec_printout(int counter, u64 *count, u64 *noise)
+{
+       double msecs = (double)count[0] / 1000000;
+
+       fprintf(stderr, " %14.6f  %-24s", msecs, event_name(counter));
+
+       if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
+               if (walltime_nsecs_avg)
+                       fprintf(stderr, " # %10.3f CPUs ",
+                               (double)count[0] / (double)walltime_nsecs_avg);
+       }
+       print_noise(count, noise);
+}
+
+static void abs_printout(int counter, u64 *count, u64 *noise)
+{
+       fprintf(stderr, " %14Ld  %-24s", count[0], event_name(counter));
+
+       if (runtime_cycles_avg &&
+           MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
+               fprintf(stderr, " # %10.3f IPC  ",
+                       (double)count[0] / (double)runtime_cycles_avg);
+       } else {
+               if (runtime_nsecs_avg) {
+                       fprintf(stderr, " # %10.3f M/sec",
+                               (double)count[0]/runtime_nsecs_avg*1000.0);
+               }
+       }
+       print_noise(count, noise);
 }
 
 /*
@@ -189,87 +321,123 @@ static void read_counter(int counter)
  */
 static void print_counter(int counter)
 {
-       __u64 *count;
+       u64 *count, *noise;
        int scaled;
 
-       count = event_res[counter];
-       scaled = event_scaled[counter];
+       count = event_res_avg[counter];
+       noise = event_res_noise[counter];
+       scaled = event_scaled_avg[counter];
 
        if (scaled == -1) {
-               fprintf(stderr, " %14s  %-20s\n",
+               fprintf(stderr, " %14s  %-24s\n",
                        "<not counted>", event_name(counter));
                return;
        }
 
-       if (nsec_counter(counter)) {
-               double msecs = (double)count[0] / 1000000;
-
-               fprintf(stderr, " %14.6f  %-20s",
-                       msecs, event_name(counter));
-               if (attrs[counter].type == PERF_TYPE_SOFTWARE &&
-                       attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK) {
+       if (nsec_counter(counter))
+               nsec_printout(counter, count, noise);
+       else
+               abs_printout(counter, count, noise);
 
-                       if (walltime_nsecs)
-                               fprintf(stderr, " # %11.3f CPU utilization factor",
-                                       (double)count[0] / (double)walltime_nsecs);
-               }
-       } else {
-               fprintf(stderr, " %14Ld  %-20s",
-                       count[0], event_name(counter));
-               if (runtime_nsecs)
-                       fprintf(stderr, " # %11.3f M/sec",
-                               (double)count[0]/runtime_nsecs*1000.0);
-               if (runtime_cycles &&
-                       attrs[counter].type == PERF_TYPE_HARDWARE &&
-                               attrs[counter].config == PERF_COUNT_HW_INSTRUCTIONS) {
-
-                       fprintf(stderr, " # %1.3f per cycle",
-                               (double)count[0] / (double)runtime_cycles);
-               }
-       }
        if (scaled)
                fprintf(stderr, "  (scaled from %.2f%%)",
                        (double) count[2] / count[1] * 100);
+
        fprintf(stderr, "\n");
 }
 
-static int do_perf_stat(int argc, const char **argv)
+/*
+ * normalize_noise noise values down to stddev:
+ */
+static void normalize_noise(u64 *val)
 {
-       unsigned long long t0, t1;
-       int counter;
-       int status;
-       int pid;
-       int i;
+       double res;
 
-       if (!system_wide)
-               nr_cpus = 1;
+       res = (double)*val / (run_count * sqrt((double)run_count));
 
-       for (counter = 0; counter < nr_counters; counter++)
-               create_perf_stat_counter(counter);
+       *val = (u64)res;
+}
 
-       /*
-        * Enable counters and exec the command:
-        */
-       t0 = rdclock();
-       prctl(PR_TASK_PERF_COUNTERS_ENABLE);
+static void update_avg(const char *name, int idx, u64 *avg, u64 *val)
+{
+       *avg += *val;
 
-       if ((pid = fork()) < 0)
-               perror("failed to fork");
+       if (verbose > 1)
+               fprintf(stderr, "debug: %20s[%d]: %Ld\n", name, idx, *val);
+}
+/*
+ * Calculate the averages and noises:
+ */
+static void calc_avg(void)
+{
+       int i, j;
+
+       if (verbose > 1)
+               fprintf(stderr, "\n");
+
+       for (i = 0; i < run_count; i++) {
+               update_avg("runtime", 0, &runtime_nsecs_avg, runtime_nsecs + i);
+               update_avg("walltime", 0, &walltime_nsecs_avg, walltime_nsecs + i);
+               update_avg("runtime_cycles", 0, &runtime_cycles_avg, runtime_cycles + i);
+
+               for (j = 0; j < nr_counters; j++) {
+                       update_avg("counter/0", j,
+                               event_res_avg[j]+0, event_res[i][j]+0);
+                       update_avg("counter/1", j,
+                               event_res_avg[j]+1, event_res[i][j]+1);
+                       update_avg("counter/2", j,
+                               event_res_avg[j]+2, event_res[i][j]+2);
+                       if (event_scaled[i][j] != (u64)-1)
+                               update_avg("scaled", j,
+                                       event_scaled_avg + j, event_scaled[i]+j);
+                       else
+                               event_scaled_avg[j] = -1;
+               }
+       }
+       runtime_nsecs_avg /= run_count;
+       walltime_nsecs_avg /= run_count;
+       runtime_cycles_avg /= run_count;
+
+       for (j = 0; j < nr_counters; j++) {
+               event_res_avg[j][0] /= run_count;
+               event_res_avg[j][1] /= run_count;
+               event_res_avg[j][2] /= run_count;
+       }
 
-       if (!pid) {
-               if (execvp(argv[0], (char **)argv)) {
-                       perror(argv[0]);
-                       exit(-1);
+       for (i = 0; i < run_count; i++) {
+               runtime_nsecs_noise +=
+                       abs((s64)(runtime_nsecs[i] - runtime_nsecs_avg));
+               walltime_nsecs_noise +=
+                       abs((s64)(walltime_nsecs[i] - walltime_nsecs_avg));
+               runtime_cycles_noise +=
+                       abs((s64)(runtime_cycles[i] - runtime_cycles_avg));
+
+               for (j = 0; j < nr_counters; j++) {
+                       event_res_noise[j][0] +=
+                               abs((s64)(event_res[i][j][0] - event_res_avg[j][0]));
+                       event_res_noise[j][1] +=
+                               abs((s64)(event_res[i][j][1] - event_res_avg[j][1]));
+                       event_res_noise[j][2] +=
+                               abs((s64)(event_res[i][j][2] - event_res_avg[j][2]));
                }
        }
 
-       while (wait(&status) >= 0)
-               ;
+       normalize_noise(&runtime_nsecs_noise);
+       normalize_noise(&walltime_nsecs_noise);
+       normalize_noise(&runtime_cycles_noise);
 
-       prctl(PR_TASK_PERF_COUNTERS_DISABLE);
-       t1 = rdclock();
+       for (j = 0; j < nr_counters; j++) {
+               normalize_noise(&event_res_noise[j][0]);
+               normalize_noise(&event_res_noise[j][1]);
+               normalize_noise(&event_res_noise[j][2]);
+       }
+}
 
-       walltime_nsecs = t1 - t0;
+static void print_stat(int argc, const char **argv)
+{
+       int i, counter;
+
+       calc_avg();
 
        fflush(stdout);
 
@@ -279,22 +447,22 @@ static int do_perf_stat(int argc, const char **argv)
        for (i = 1; i < argc; i++)
                fprintf(stderr, " %s", argv[i]);
 
-       fprintf(stderr, "\':\n");
-       fprintf(stderr, "\n");
-
-       for (counter = 0; counter < nr_counters; counter++)
-               read_counter(counter);
+       fprintf(stderr, "\'");
+       if (run_count > 1)
+               fprintf(stderr, " (%d runs)", run_count);
+       fprintf(stderr, ":\n\n");
 
        for (counter = 0; counter < nr_counters; counter++)
                print_counter(counter);
 
-
        fprintf(stderr, "\n");
-       fprintf(stderr, " Wall-clock time elapsed: %12.6f msecs\n",
-                       (double)(t1-t0)/1e6);
-       fprintf(stderr, "\n");
-
-       return 0;
+       fprintf(stderr, " %14.9f  seconds time elapsed",
+                       (double)walltime_nsecs_avg/1e9);
+       if (run_count > 1) {
+               fprintf(stderr, "   ( +- %7.3f%% )",
+                       100.0*(double)walltime_nsecs_noise/(double)walltime_nsecs_avg);
+       }
+       fprintf(stderr, "\n\n");
 }
 
 static volatile int signr = -1;
@@ -327,30 +495,38 @@ static const struct option options[] = {
        OPT_INTEGER('p', "pid", &target_pid,
                    "stat events on existing pid"),
        OPT_BOOLEAN('a', "all-cpus", &system_wide,
-                           "system-wide collection from all CPUs"),
-       OPT_BOOLEAN('S', "scale", &scale,
-                           "scale/normalize counters"),
+                   "system-wide collection from all CPUs"),
+       OPT_BOOLEAN('c', "scale", &scale,
+                   "scale/normalize counters"),
        OPT_BOOLEAN('v', "verbose", &verbose,
                    "be more verbose (show counter open errors, etc)"),
+       OPT_INTEGER('r', "repeat", &run_count,
+                   "repeat command and print average + stddev (max: 100)"),
+       OPT_BOOLEAN('n', "null", &null_run,
+                   "null run - dont start any counters"),
        OPT_END()
 };
 
-int cmd_stat(int argc, const char **argv, const char *prefix)
+int cmd_stat(int argc, const char **argv, const char *prefix __used)
 {
-       page_size = sysconf(_SC_PAGE_SIZE);
-
-       memcpy(attrs, default_attrs, sizeof(attrs));
+       int status;
 
-       argc = parse_options(argc, argv, options, stat_usage, 0);
+       argc = parse_options(argc, argv, options, stat_usage,
+               PARSE_OPT_STOP_AT_NON_OPTION);
        if (!argc)
                usage_with_options(stat_usage, options);
+       if (run_count <= 0 || run_count > MAX_RUN)
+               usage_with_options(stat_usage, options);
 
-       if (!nr_counters)
-               nr_counters = 8;
+       /* Set attrs and nr_counters if no event is selected and !null_run */
+       if (!null_run && !nr_counters) {
+               memcpy(attrs, default_attrs, sizeof(default_attrs));
+               nr_counters = ARRAY_SIZE(default_attrs);
+       }
 
        nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
        assert(nr_cpus <= MAX_NR_CPUS);
-       assert(nr_cpus >= 0);
+       assert((int)nr_cpus >= 0);
 
        /*
         * We dont want to block the signals - that would cause
@@ -363,5 +539,14 @@ int cmd_stat(int argc, const char **argv, const char *prefix)
        signal(SIGALRM, skip_signal);
        signal(SIGABRT, skip_signal);
 
-       return do_perf_stat(argc, argv);
+       status = 0;
+       for (run_idx = 0; run_idx < run_count; run_idx++) {
+               if (run_count != 1 && verbose)
+                       fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
+               status = run_perf_stat(argc, argv);
+       }
+
+       print_stat(argc, argv);
+
+       return status;
 }