perf newt: Fix the 'A'/'a' shortcut for annotate
[safe/jmp/linux-2.6] / tools / perf / builtin-stat.c
index 52c176c..ff8c413 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)
  */
 #include "util/util.h"
 #include "util/parse-options.h"
 #include "util/parse-events.h"
+#include "util/event.h"
+#include "util/debug.h"
+#include "util/header.h"
+#include "util/cpumap.h"
+#include "util/thread.h"
 
 #include <sys/prctl.h>
 #include <math.h>
 
-static struct perf_counter_attr default_attrs[MAX_COUNTERS] = {
+static struct perf_event_attr default_attrs[] = {
 
-  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK     },
-  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES},
-  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
-  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS    },
+  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK             },
+  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES       },
+  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS         },
+  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS            },
 
-  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES     },
-  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS   },
-  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES},
-  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES   },
+  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES             },
+  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS           },
+  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS    },
+  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES          },
+  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES       },
+  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES           },
 
 };
 
-#define MAX_RUN                        100
-
-static int                     system_wide                     =  0;
-static int                     verbose                         =  0;
-static int                     nr_cpus                         =  0;
+static bool                    system_wide                     =  false;
+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 bool                    no_inherit                      = false;
+static bool                    scale                           =  true;
+static pid_t                   target_pid                      = -1;
+static pid_t                   target_tid                      = -1;
+static pid_t                   *all_tids                       =  NULL;
+static int                     thread_num                      =  0;
+static pid_t                   child_pid                       = -1;
+static bool                    null_run                        =  false;
 
-static int                     fd[MAX_NR_CPUS][MAX_COUNTERS];
+static int                     *fd[MAX_NR_CPUS][MAX_COUNTERS];
 
-static u64                     runtime_nsecs[MAX_RUN];
-static u64                     walltime_nsecs[MAX_RUN];
-static u64                     runtime_cycles[MAX_RUN];
+static int                     event_scaled[MAX_COUNTERS];
 
-static u64                     event_res[MAX_RUN][MAX_COUNTERS][3];
-static u64                     event_scaled[MAX_RUN][MAX_COUNTERS];
+static volatile int done = 0;
 
-static u64                     event_res_avg[MAX_COUNTERS][3];
-static u64                     event_res_noise[MAX_COUNTERS][3];
+struct stats
+{
+       double n, mean, M2;
+};
 
-static u64                     event_scaled_avg[MAX_COUNTERS];
+static void update_stats(struct stats *stats, u64 val)
+{
+       double delta;
 
-static u64                     runtime_nsecs_avg;
-static u64                     runtime_nsecs_noise;
+       stats->n++;
+       delta = val - stats->mean;
+       stats->mean += delta / stats->n;
+       stats->M2 += delta*(val - stats->mean);
+}
 
-static u64                     walltime_nsecs_avg;
-static u64                     walltime_nsecs_noise;
+static double avg_stats(struct stats *stats)
+{
+       return stats->mean;
+}
 
-static u64                     runtime_cycles_avg;
-static u64                     runtime_cycles_noise;
+/*
+ * 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 = stats->M2 / (stats->n - 1);
+       double variance_mean = variance / stats->n;
+
+       return sqrt(variance_mean);
+}
+
+struct stats                   event_res_stats[MAX_COUNTERS][3];
+struct stats                   runtime_nsecs_stats;
+struct stats                   walltime_nsecs_stats;
+struct stats                   runtime_cycles_stats;
+struct stats                   runtime_branches_stats;
+
+#define MATCH_EVENT(t, c, counter)                     \
+       (attrs[counter].type == PERF_TYPE_##t &&        \
+        attrs[counter].config == PERF_COUNT_##c)
 
 #define ERR_PERF_OPEN \
-"Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n"
+"Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
 
-static void create_perf_stat_counter(int counter)
+static int create_perf_stat_counter(int counter)
 {
-       struct perf_counter_attr *attr = attrs + counter;
+       struct perf_event_attr *attr = attrs + counter;
+       int thread;
+       int ncreated = 0;
 
        if (scale)
                attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
                                    PERF_FORMAT_TOTAL_TIME_RUNNING;
 
        if (system_wide) {
-               int 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)
-                               fprintf(stderr, ERR_PERF_OPEN, counter,
-                                       fd[cpu][counter], strerror(errno));
+                       fd[cpu][counter][0] = sys_perf_event_open(attr,
+                                       -1, cpumap[cpu], -1, 0);
+                       if (fd[cpu][counter][0] < 0)
+                               pr_debug(ERR_PERF_OPEN, counter,
+                                        fd[cpu][counter][0], strerror(errno));
+                       else
+                               ++ncreated;
                }
        } 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)
-                       fprintf(stderr, ERR_PERF_OPEN, counter,
-                               fd[0][counter], strerror(errno));
+               attr->inherit = !no_inherit;
+               if (target_pid == -1 && target_tid == -1) {
+                       attr->disabled = 1;
+                       attr->enable_on_exec = 1;
+               }
+               for (thread = 0; thread < thread_num; thread++) {
+                       fd[0][counter][thread] = sys_perf_event_open(attr,
+                               all_tids[thread], -1, -1, 0);
+                       if (fd[0][counter][thread] < 0)
+                               pr_debug(ERR_PERF_OPEN, counter,
+                                        fd[0][counter][thread],
+                                        strerror(errno));
+                       else
+                               ++ncreated;
+               }
        }
+
+       return ncreated;
 }
 
 /*
@@ -130,13 +192,8 @@ 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;
@@ -147,92 +204,159 @@ 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[3], single_count[3];
+       unsigned int cpu;
+       size_t res, nv;
        int scaled;
-
-       count = event_res[run_idx][counter];
+       int i, thread;
 
        count[0] = count[1] = count[2] = 0;
 
        nv = scale ? 3 : 1;
        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));
-               close(fd[cpu][counter]);
-               fd[cpu][counter] = -1;
-
-               count[0] += single_count[0];
-               if (scale) {
-                       count[1] += single_count[1];
-                       count[2] += single_count[2];
+               for (thread = 0; thread < thread_num; thread++) {
+                       if (fd[cpu][counter][thread] < 0)
+                               continue;
+
+                       res = read(fd[cpu][counter][thread],
+                                       single_count, nv * sizeof(u64));
+                       assert(res == nv * sizeof(u64));
+
+                       close(fd[cpu][counter][thread]);
+                       fd[cpu][counter][thread] = -1;
+
+                       count[0] += single_count[0];
+                       if (scale) {
+                               count[1] += single_count[1];
+                               count[2] += single_count[2];
+                       }
                }
        }
 
        scaled = 0;
        if (scale) {
                if (count[2] == 0) {
-                       event_scaled[run_idx][counter] = -1;
+                       event_scaled[counter] = -1;
                        count[0] = 0;
                        return;
                }
 
                if (count[2] < count[1]) {
-                       event_scaled[run_idx][counter] = 1;
+                       event_scaled[counter] = 1;
                        count[0] = (unsigned long long)
                                ((double)count[0] * count[1] / count[2] + 0.5);
                }
        }
+
+       for (i = 0; i < 3; i++)
+               update_stats(&event_res_stats[counter][i], count[i]);
+
+       if (verbose) {
+               fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
+                               count[0], count[1], count[2]);
+       }
+
        /*
         * 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[run_idx] = count[0];
-       if (attrs[counter].type == PERF_TYPE_HARDWARE &&
-               attrs[counter].config == PERF_COUNT_HW_CPU_CYCLES)
-               runtime_cycles[run_idx] = count[0];
+       if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
+               update_stats(&runtime_nsecs_stats, count[0]);
+       if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
+               update_stats(&runtime_cycles_stats, count[0]);
+       if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
+               update_stats(&runtime_branches_stats, count[0]);
 }
 
-static int run_perf_stat(int argc, const char **argv)
+static int run_perf_stat(int argc __used, const char **argv)
 {
        unsigned long long t0, t1;
        int status = 0;
-       int counter;
-       int pid;
+       int counter, ncreated = 0;
+       int child_ready_pipe[2], go_pipe[2];
+       const bool forks = (argc > 0);
+       char buf;
 
        if (!system_wide)
                nr_cpus = 1;
 
-       for (counter = 0; counter < nr_counters; counter++)
-               create_perf_stat_counter(counter);
+       if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
+               perror("failed to create pipes");
+               exit(1);
+       }
 
-       /*
-        * Enable counters and exec the command:
-        */
-       t0 = rdclock();
-       prctl(PR_TASK_PERF_COUNTERS_ENABLE);
+       if (forks) {
+               if ((child_pid = fork()) < 0)
+                       perror("failed to fork");
+
+               if (!child_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]);
 
-       if ((pid = fork()) < 0)
-               perror("failed to fork");
+                       /*
+                        * 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);
 
-       if (!pid) {
-               if (execvp(argv[0], (char **)argv)) {
                        perror(argv[0]);
                        exit(-1);
                }
+
+               if (target_tid == -1 && target_pid == -1 && !system_wide)
+                       all_tids[0] = child_pid;
+
+               /*
+                * 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]);
        }
 
-       wait(&status);
+       for (counter = 0; counter < nr_counters; counter++)
+               ncreated += create_perf_stat_counter(counter);
+
+       if (ncreated == 0) {
+               pr_err("No permission to collect %sstats.\n"
+                      "Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n",
+                      system_wide ? "system-wide " : "");
+               if (child_pid != -1)
+                       kill(child_pid, SIGTERM);
+               return -1;
+       }
+
+       /*
+        * Enable counters and exec the command:
+        */
+       t0 = rdclock();
+
+       if (forks) {
+               close(go_pipe[1]);
+               wait(&status);
+       } else {
+               while(!done) sleep(1);
+       }
 
-       prctl(PR_TASK_PERF_COUNTERS_DISABLE);
        t1 = rdclock();
 
-       walltime_nsecs[run_idx] = t1 - t0;
+       update_stats(&walltime_nsecs_stats, t1 - t0);
 
        for (counter = 0; counter < nr_counters; counter++)
                read_counter(counter);
@@ -240,46 +364,57 @@ static int run_perf_stat(int argc, const char **argv)
        return WEXITSTATUS(status);
 }
 
-static void print_noise(u64 *count, u64 *noise)
+static void print_noise(int counter, double avg)
 {
-       if (run_count > 1)
-               fprintf(stderr, "   ( +- %7.3f%% )",
-                       (double)noise[0]/(count[0]+1)*100.0);
+       if (run_count == 1)
+               return;
+
+       fprintf(stderr, "   ( +- %7.3f%% )",
+                       100 * stddev_stats(&event_res_stats[counter][0]) / avg);
 }
 
-static void nsec_printout(int counter, u64 *count, u64 *noise)
+static void nsec_printout(int counter, double avg)
 {
-       double msecs = (double)count[0] / 1000000;
+       double msecs = avg / 1e6;
 
-       fprintf(stderr, " %14.6f  %-20s", msecs, event_name(counter));
+       fprintf(stderr, " %14.6f  %-24s", msecs, event_name(counter));
 
-       if (attrs[counter].type == PERF_TYPE_SOFTWARE &&
-               attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK) {
-
-               if (walltime_nsecs_avg)
-                       fprintf(stderr, " # %10.3f CPUs ",
-                               (double)count[0] / (double)walltime_nsecs_avg);
+       if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
+               fprintf(stderr, " # %10.3f CPUs ",
+                               avg / avg_stats(&walltime_nsecs_stats));
        }
-       print_noise(count, noise);
 }
 
-static void abs_printout(int counter, u64 *count, u64 *noise)
+static void abs_printout(int counter, double avg)
 {
-       fprintf(stderr, " %14Ld  %-20s", count[0], event_name(counter));
+       double total, ratio = 0.0;
 
-       if (runtime_cycles_avg &&
-               attrs[counter].type == PERF_TYPE_HARDWARE &&
-                       attrs[counter].config == PERF_COUNT_HW_INSTRUCTIONS) {
+       fprintf(stderr, " %14.0f  %-24s", avg, event_name(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);
-               }
+       if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
+               total = avg_stats(&runtime_cycles_stats);
+
+               if (total)
+                       ratio = avg / total;
+
+               fprintf(stderr, " # %10.3f IPC  ", ratio);
+       } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter) &&
+                       runtime_branches_stats.n != 0) {
+               total = avg_stats(&runtime_branches_stats);
+
+               if (total)
+                       ratio = avg * 100 / total;
+
+               fprintf(stderr, " # %10.3f %%    ", ratio);
+
+       } else if (runtime_nsecs_stats.n != 0) {
+               total = avg_stats(&runtime_nsecs_stats);
+
+               if (total)
+                       ratio = 1000.0 * avg / total;
+
+               fprintf(stderr, " # %10.3f M/sec", ratio);
        }
-       print_noise(count, noise);
 }
 
 /*
@@ -287,131 +422,51 @@ static void abs_printout(int counter, u64 *count, u64 *noise)
  */
 static void print_counter(int counter)
 {
-       u64 *count, *noise;
-       int scaled;
-
-       count = event_res_avg[counter];
-       noise = event_res_noise[counter];
-       scaled = event_scaled_avg[counter];
+       double avg = avg_stats(&event_res_stats[counter][0]);
+       int scaled = event_scaled[counter];
 
        if (scaled == -1) {
-               fprintf(stderr, " %14s  %-20s\n",
+               fprintf(stderr, " %14s  %-24s\n",
                        "<not counted>", event_name(counter));
                return;
        }
 
        if (nsec_counter(counter))
-               nsec_printout(counter, count, noise);
+               nsec_printout(counter, avg);
        else
-               abs_printout(counter, count, noise);
+               abs_printout(counter, avg);
 
-       if (scaled)
-               fprintf(stderr, "  (scaled from %.2f%%)",
-                       (double) count[2] / count[1] * 100);
+       print_noise(counter, avg);
 
-       fprintf(stderr, "\n");
-}
-
-/*
- * normalize_noise noise values down to stddev:
- */
-static void normalize_noise(u64 *val)
-{
-       double res;
-
-       res = (double)*val / (run_count * sqrt((double)run_count));
+       if (scaled) {
+               double avg_enabled, avg_running;
 
-       *val = (u64)res;
-}
-
-static void update_avg(const char *name, int idx, u64 *avg, u64 *val)
-{
-       *avg += *val;
+               avg_enabled = avg_stats(&event_res_stats[counter][1]);
+               avg_running = avg_stats(&event_res_stats[counter][2]);
 
-       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] != -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;
-       }
-
-       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]));
-               }
+               fprintf(stderr, "  (scaled from %.2f%%)",
+                               100 * avg_running / avg_enabled);
        }
 
-       normalize_noise(&runtime_nsecs_noise);
-       normalize_noise(&walltime_nsecs_noise);
-       normalize_noise(&runtime_cycles_noise);
-
-       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]);
-       }
+       fprintf(stderr, "\n");
 }
 
 static void print_stat(int argc, const char **argv)
 {
        int i, counter;
 
-       calc_avg();
-
        fflush(stdout);
 
        fprintf(stderr, "\n");
-       fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
-
-       for (i = 1; i < argc; i++)
-               fprintf(stderr, " %s", argv[i]);
+       fprintf(stderr, " Performance counter stats for ");
+       if(target_pid == -1 && target_tid == -1) {
+               fprintf(stderr, "\'%s", argv[0]);
+               for (i = 1; i < argc; i++)
+                       fprintf(stderr, " %s", argv[i]);
+       } else if (target_pid != -1)
+               fprintf(stderr, "process id \'%d", target_pid);
+       else
+               fprintf(stderr, "thread id \'%d", target_tid);
 
        fprintf(stderr, "\'");
        if (run_count > 1)
@@ -421,13 +476,13 @@ static void print_stat(int argc, const char **argv)
        for (counter = 0; counter < nr_counters; counter++)
                print_counter(counter);
 
-
        fprintf(stderr, "\n");
        fprintf(stderr, " %14.9f  seconds time elapsed",
-                       (double)walltime_nsecs_avg/1e9);
+                       avg_stats(&walltime_nsecs_stats)/1e9);
        if (run_count > 1) {
                fprintf(stderr, "   ( +- %7.3f%% )",
-                       100.0*(double)walltime_nsecs_noise/(double)walltime_nsecs_avg);
+                               100*stddev_stats(&walltime_nsecs_stats) /
+                               avg_stats(&walltime_nsecs_stats));
        }
        fprintf(stderr, "\n\n");
 }
@@ -436,11 +491,17 @@ static volatile int signr = -1;
 
 static void skip_signal(int signo)
 {
+       if(child_pid == -1)
+               done = 1;
+
        signr = signo;
 }
 
 static void sig_atexit(void)
 {
+       if (child_pid != -1)
+               kill(child_pid, SIGTERM);
+
        if (signr == -1)
                return;
 
@@ -449,7 +510,7 @@ static void sig_atexit(void)
 }
 
 static const char * const stat_usage[] = {
-       "perf stat [<options>] <command>",
+       "perf stat [<options>] [<command>]",
        NULL
 };
 
@@ -457,15 +518,17 @@ static const struct option options[] = {
        OPT_CALLBACK('e', "event", NULL, "event",
                     "event selector. use 'perf list' to list available events",
                     parse_events),
-       OPT_BOOLEAN('i', "inherit", &inherit,
-                   "child tasks inherit counters"),
+       OPT_BOOLEAN('i', "no-inherit", &no_inherit,
+                   "child tasks do not inherit counters"),
        OPT_INTEGER('p', "pid", &target_pid,
-                   "stat events on existing pid"),
+                   "stat events on existing process id"),
+       OPT_INTEGER('t', "tid", &target_tid,
+                   "stat events on existing thread id"),
        OPT_BOOLEAN('a', "all-cpus", &system_wide,
                    "system-wide collection from all CPUs"),
-       OPT_BOOLEAN('S', "scale", &scale,
+       OPT_BOOLEAN('c', "scale", &scale,
                    "scale/normalize counters"),
-       OPT_BOOLEAN('v', "verbose", &verbose,
+       OPT_INCR('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)"),
@@ -474,24 +537,53 @@ static const struct option options[] = {
        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)
 {
        int status;
+       int i,j;
 
-       memcpy(attrs, default_attrs, sizeof(attrs));
-
-       argc = parse_options(argc, argv, options, stat_usage, 0);
-       if (!argc)
+       argc = parse_options(argc, argv, options, stat_usage,
+               PARSE_OPT_STOP_AT_NON_OPTION);
+       if (!argc && target_pid == -1 && target_tid == -1)
                usage_with_options(stat_usage, options);
-       if (run_count <= 0 || run_count > MAX_RUN)
+       if (run_count <= 0)
                usage_with_options(stat_usage, options);
 
-       if (!null_run && !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);
+       }
+
+       if (system_wide)
+               nr_cpus = read_cpu_map();
+       else
+               nr_cpus = 1;
+
+       if (target_pid != -1) {
+               target_tid = target_pid;
+               thread_num = find_all_tid(target_pid, &all_tids);
+               if (thread_num <= 0) {
+                       fprintf(stderr, "Can't find all threads of pid %d\n",
+                                       target_pid);
+                       usage_with_options(stat_usage, options);
+               }
+       } else {
+               all_tids=malloc(sizeof(pid_t));
+               if (!all_tids)
+                       return -ENOMEM;
 
-       nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
-       assert(nr_cpus <= MAX_NR_CPUS);
-       assert(nr_cpus >= 0);
+               all_tids[0] = target_tid;
+               thread_num = 1;
+       }
+
+       for (i = 0; i < MAX_NR_CPUS; i++) {
+               for (j = 0; j < MAX_COUNTERS; j++) {
+                       fd[i][j] = malloc(sizeof(int)*thread_num);
+                       if (!fd[i][j])
+                               return -ENOMEM;
+               }
+       }
 
        /*
         * We dont want to block the signals - that would cause
@@ -511,7 +603,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix)
                status = run_perf_stat(argc, argv);
        }
 
-       print_stat(argc, argv);
+       if (status != -1)
+               print_stat(argc, argv);
 
        return status;
 }