/*

   * builtin-stat.c
   *
   * Builtin stat command: Give a precise performance counters summary
   * overview about any workload, CPU or specific PID.
   *
   * Sample output:

     $ perf stat ./hackbench 10

    Time: 0.118

    Performance counter stats for './hackbench 10':

         1708.761321 task-clock                #   11.037 CPUs utilized
              41,190 context-switches          #    0.024 M/sec
               6,735 CPU-migrations            #    0.004 M/sec
              17,318 page-faults               #    0.010 M/sec
       5,205,202,243 cycles                    #    3.046 GHz
       3,856,436,920 stalled-cycles-frontend   #   74.09% frontend cycles idle
       1,600,790,871 stalled-cycles-backend    #   30.75% backend  cycles idle
       2,603,501,247 instructions              #    0.50  insns per cycle
                                               #    1.48  stalled cycles per insn
         484,357,498 branches                  #  283.455 M/sec
           6,388,934 branch-misses             #    1.32% of all branches
  
          0.154822978  seconds time elapsed

   *

   * Copyright (C) 2008-2011, Red Hat Inc, Ingo Molnar <mingo@redhat.com>

   *
   * Improvements and fixes by:
   *
   *   Arjan van de Ven <arjan@linux.intel.com>
   *   Yanmin Zhang <yanmin.zhang@intel.com>
   *   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 "perf.h"

  #include "builtin.h"

  #include "util/util.h"

  #include "util/parse-options.h"
  #include "util/parse-events.h"

  #include "util/event.h"

  #include "util/evlist.h"

  #include "util/evsel.h"

  #include "util/debug.h"

  #include "util/color.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	" "

  #define CNTR_NOT_SUPPORTED	"<not supported>"
  #define CNTR_NOT_COUNTED	"<not counted>"

  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_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES		},

    { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_FRONTEND	},
    { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_BACKEND	},

    { .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		},

  };

  /*

   * Detailed stats (-d), covering the L1 and last level data caches:

   */
  static struct perf_event_attr detailed_attrs[] = {

    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_L1D		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_ACCESS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_L1D		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_MISS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_LL			<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_ACCESS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_LL			<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_MISS	<< 16)				},
  };

  /*
   * Very detailed stats (-d -d), covering the instruction cache and the TLB caches:
   */
  static struct perf_event_attr very_detailed_attrs[] = {
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_L1I		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_ACCESS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_L1I		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_MISS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_DTLB		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_ACCESS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_DTLB		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_MISS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_ITLB		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_ACCESS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_ITLB		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_READ		<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_MISS	<< 16)				},
  
  };
  
  /*
   * Very, very detailed stats (-d -d -d), adding prefetch events:
   */
  static struct perf_event_attr very_very_detailed_attrs[] = {
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_L1D		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_PREFETCH	<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_ACCESS	<< 16)				},
  
    { .type = PERF_TYPE_HW_CACHE,
      .config =
  	 PERF_COUNT_HW_CACHE_L1D		<<  0  |
  	(PERF_COUNT_HW_CACHE_OP_PREFETCH	<<  8) |
  	(PERF_COUNT_HW_CACHE_RESULT_MISS	<< 16)				},
  };

  struct perf_evlist		*evsel_list;

  static bool			system_wide			=  false;

  static int			run_idx				=  0;

  static int			run_count			=  1;

  static bool			no_inherit			= false;

  static bool			scale				=  true;

  static bool			no_aggr				= false;

  static pid_t			target_pid			= -1;

  static pid_t			target_tid			= -1;

  static pid_t			child_pid			= -1;

  static bool			null_run			=  false;

  static int			detailed_run			=  0;

  static bool			sync_run			=  false;

  static bool			big_num				=  true;

  static int			big_num_opt			=  -1;

  static const char		*cpu_list;

  static const char		*csv_sep			= NULL;
  static bool			csv_output			= false;

  static bool			group				= false;

  static const char		*output_name			= NULL;
  static FILE			*output				= NULL;

  static int			output_fd;

  static volatile int done = 0;

  struct stats
  {

  	double n, mean, M2;

  };

  struct perf_stat {
  	struct stats	  res_stats[3];

  };

  static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)

  {

  	evsel->priv = zalloc(sizeof(struct perf_stat));

  	return evsel->priv == NULL ? -ENOMEM : 0;
  }
  
  static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
  {
  	free(evsel->priv);
  	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);

  }

  struct stats			runtime_nsecs_stats[MAX_NR_CPUS];
  struct stats			runtime_cycles_stats[MAX_NR_CPUS];

  struct stats			runtime_stalled_cycles_front_stats[MAX_NR_CPUS];
  struct stats			runtime_stalled_cycles_back_stats[MAX_NR_CPUS];

  struct stats			runtime_branches_stats[MAX_NR_CPUS];

  struct stats			runtime_cacherefs_stats[MAX_NR_CPUS];

  struct stats			runtime_l1_dcache_stats[MAX_NR_CPUS];

  struct stats			runtime_l1_icache_stats[MAX_NR_CPUS];
  struct stats			runtime_ll_cache_stats[MAX_NR_CPUS];
  struct stats			runtime_itlb_cache_stats[MAX_NR_CPUS];
  struct stats			runtime_dtlb_cache_stats[MAX_NR_CPUS];

  struct stats			walltime_nsecs_stats;

  static int create_perf_stat_counter(struct perf_evsel *evsel,
  				    struct perf_evsel *first)

  {

  	struct perf_event_attr *attr = &evsel->attr;

  	struct xyarray *group_fd = NULL;
  
  	if (group && evsel != first)
  		group_fd = first->fd;

  	if (scale)

  		attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
  				    PERF_FORMAT_TOTAL_TIME_RUNNING;

  	attr->inherit = !no_inherit;

  	if (system_wide)

  		return perf_evsel__open_per_cpu(evsel, evsel_list->cpus,
  						group, group_fd);

  	if (target_pid == -1 && target_tid == -1) {
  		attr->disabled = 1;
  		attr->enable_on_exec = 1;

  	}

  	return perf_evsel__open_per_thread(evsel, evsel_list->threads,
  					   group, group_fd);

  }

  /*
   * Does the counter have nsecs as a unit?
   */

  static inline int nsec_counter(struct perf_evsel *evsel)

  {

  	if (perf_evsel__match(evsel, SOFTWARE, SW_CPU_CLOCK) ||
  	    perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))

  		return 1;
  
  	return 0;
  }
  
  /*

   * Update various tracking values we maintain to print
   * more semantic information such as miss/hit ratios,
   * instruction rates, etc:
   */
  static void update_shadow_stats(struct perf_evsel *counter, u64 *count)
  {
  	if (perf_evsel__match(counter, SOFTWARE, SW_TASK_CLOCK))
  		update_stats(&runtime_nsecs_stats[0], count[0]);
  	else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
  		update_stats(&runtime_cycles_stats[0], count[0]);

  	else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND))
  		update_stats(&runtime_stalled_cycles_front_stats[0], count[0]);

  	else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_BACKEND))

  		update_stats(&runtime_stalled_cycles_back_stats[0], count[0]);

  	else if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
  		update_stats(&runtime_branches_stats[0], count[0]);
  	else if (perf_evsel__match(counter, HARDWARE, HW_CACHE_REFERENCES))
  		update_stats(&runtime_cacherefs_stats[0], count[0]);

  	else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_L1D))
  		update_stats(&runtime_l1_dcache_stats[0], count[0]);

  	else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_L1I))
  		update_stats(&runtime_l1_icache_stats[0], count[0]);
  	else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_LL))
  		update_stats(&runtime_ll_cache_stats[0], count[0]);
  	else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_DTLB))
  		update_stats(&runtime_dtlb_cache_stats[0], count[0]);
  	else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_ITLB))
  		update_stats(&runtime_itlb_cache_stats[0], count[0]);

  }
  
  /*

   * Read out the results of a single counter:

   * aggregate counts across CPUs in system-wide mode

   */

  static int read_counter_aggr(struct perf_evsel *counter)

  {

  	struct perf_stat *ps = counter->priv;

  	u64 *count = counter->counts->aggr.values;
  	int i;

  	if (__perf_evsel__read(counter, evsel_list->cpus->nr,
  			       evsel_list->threads->nr, scale) < 0)

  		return -1;

  
  	for (i = 0; i < 3; i++)

  		update_stats(&ps->res_stats[i], count[i]);

  
  	if (verbose) {

  		fprintf(output, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "
  ",

  			event_name(counter), count[0], count[1], count[2]);

  	}

  	/*
  	 * Save the full runtime - to allow normalization during printout:
  	 */

  	update_shadow_stats(counter, count);

  
  	return 0;

  }
  
  /*
   * Read out the results of a single counter:
   * do not aggregate counts across CPUs in system-wide mode
   */

  static int read_counter(struct perf_evsel *counter)

  {

  	u64 *count;

  	int cpu;

  	for (cpu = 0; cpu < evsel_list->cpus->nr; cpu++) {

  		if (__perf_evsel__read_on_cpu(counter, cpu, 0, scale) < 0)
  			return -1;

  		count = counter->counts->cpu[cpu].values;

  		update_shadow_stats(counter, count);

  	}

  
  	return 0;

  }

  static int run_perf_stat(int argc __used, const char **argv)

  {
  	unsigned long long t0, t1;

  	struct perf_evsel *counter, *first;

  	int status = 0;

  	int child_ready_pipe[2], go_pipe[2];

  	const bool forks = (argc > 0);

  	char buf;

  	if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {

  		perror("failed to create pipes");
  		exit(1);
  	}

  	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]);
  
  			/*
  			 * 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);
  		}

  		if (target_tid == -1 && target_pid == -1 && !system_wide)

  			evsel_list->threads->map[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]);

  	}

  	first = list_entry(evsel_list->entries.next, struct perf_evsel, node);

  	list_for_each_entry(counter, &evsel_list->entries, node) {

  		if (create_perf_stat_counter(counter, first) < 0) {

  			if (errno == EINVAL || errno == ENOSYS ||
  			    errno == ENOENT || errno == EOPNOTSUPP) {

  				if (verbose)
  					ui__warning("%s event is not supported by the kernel.
  ",
  						    event_name(counter));

  				counter->supported = false;

  				continue;

  			}

  
  			if (errno == EPERM || errno == EACCES) {

  				error("You may not have permission to collect %sstats.
  "
  				      "\t Consider tweaking"
  				      " /proc/sys/kernel/perf_event_paranoid or running as root.",
  				      system_wide ? "system-wide " : "");
  			} else {
  				error("open_counter returned with %d (%s). "
  				      "/bin/dmesg may provide additional information.
  ",
  				       errno, strerror(errno));
  			}
  			if (child_pid != -1)
  				kill(child_pid, SIGTERM);
  			die("Not all events could be opened.
  ");
  			return -1;
  		}

  		counter->supported = true;

  	}

  	if (perf_evlist__set_filters(evsel_list)) {
  		error("failed to set filter with %d (%s)
  ", errno,
  			strerror(errno));
  		return -1;
  	}

  	/*
  	 * Enable counters and exec the command:
  	 */
  	t0 = rdclock();

  	if (forks) {
  		close(go_pipe[1]);
  		wait(&status);

  		if (WIFSIGNALED(status))
  			psignal(WTERMSIG(status), argv[0]);

  	} else {

  		while(!done) sleep(1);

  	}

  	t1 = rdclock();

  	update_stats(&walltime_nsecs_stats, t1 - t0);

  	if (no_aggr) {

  		list_for_each_entry(counter, &evsel_list->entries, node) {

  			read_counter(counter);

  			perf_evsel__close_fd(counter, evsel_list->cpus->nr, 1);

  		}

  	} else {

  		list_for_each_entry(counter, &evsel_list->entries, node) {

  			read_counter_aggr(counter);

  			perf_evsel__close_fd(counter, evsel_list->cpus->nr,
  					     evsel_list->threads->nr);

  		}

  	}

  	return WEXITSTATUS(status);
  }

  static void print_noise_pct(double total, double avg)
  {
  	double pct = 0.0;
  
  	if (avg)
  		pct = 100.0*total/avg;

  	if (csv_output)

  		fprintf(output, "%s%.2f%%", csv_sep, pct);

  	else if (pct)

  		fprintf(output, "  ( +-%6.2f%% )", pct);

  }

  static void print_noise(struct perf_evsel *evsel, double avg)

  {

  	struct perf_stat *ps;

  	if (run_count == 1)
  		return;

  	ps = evsel->priv;

  	print_noise_pct(stddev_stats(&ps->res_stats[0]), avg);

  }

  static void nsec_printout(int cpu, struct perf_evsel *evsel, double avg)

  {

  	double msecs = avg / 1e6;

  	char cpustr[16] = { '\0', };

  	const char *fmt = csv_output ? "%s%.6f%s%s" : "%s%18.6f%s%-25s";

  	if (no_aggr)

  		sprintf(cpustr, "CPU%*d%s",
  			csv_output ? 0 : -4,

  			evsel_list->cpus->map[cpu], csv_sep);

  	fprintf(output, fmt, cpustr, msecs, csv_sep, event_name(evsel));

  	if (evsel->cgrp)

  		fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);

  	if (csv_output)
  		return;

  	if (perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))

  		fprintf(output, " # %8.3f CPUs utilized          ",
  			avg / avg_stats(&walltime_nsecs_stats));

  }

  /* used for get_ratio_color() */
  enum grc_type {
  	GRC_STALLED_CYCLES_FE,
  	GRC_STALLED_CYCLES_BE,
  	GRC_CACHE_MISSES,
  	GRC_MAX_NR
  };
  
  static const char *get_ratio_color(enum grc_type type, double ratio)
  {
  	static const double grc_table[GRC_MAX_NR][3] = {
  		[GRC_STALLED_CYCLES_FE] = { 50.0, 30.0, 10.0 },
  		[GRC_STALLED_CYCLES_BE] = { 75.0, 50.0, 20.0 },
  		[GRC_CACHE_MISSES] 	= { 20.0, 10.0, 5.0 },
  	};
  	const char *color = PERF_COLOR_NORMAL;
  
  	if (ratio > grc_table[type][0])
  		color = PERF_COLOR_RED;
  	else if (ratio > grc_table[type][1])
  		color = PERF_COLOR_MAGENTA;
  	else if (ratio > grc_table[type][2])
  		color = PERF_COLOR_YELLOW;
  
  	return color;
  }

  static void print_stalled_cycles_frontend(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_cycles_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_STALLED_CYCLES_FE, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " frontend cycles idle   ");

  }
  
  static void print_stalled_cycles_backend(int cpu, struct perf_evsel *evsel __used, double avg)

  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_cycles_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_STALLED_CYCLES_BE, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " backend  cycles idle   ");

  }

  static void print_branch_misses(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_branches_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_CACHE_MISSES, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " of all branches        ");

  }

  static void print_l1_dcache_misses(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_l1_dcache_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_CACHE_MISSES, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " of all L1-dcache hits  ");

  }

  static void print_l1_icache_misses(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_l1_icache_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_CACHE_MISSES, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " of all L1-icache hits  ");

  }
  
  static void print_dtlb_cache_misses(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_dtlb_cache_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_CACHE_MISSES, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " of all dTLB cache hits ");

  }
  
  static void print_itlb_cache_misses(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_itlb_cache_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_CACHE_MISSES, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " of all iTLB cache hits ");

  }
  
  static void print_ll_cache_misses(int cpu, struct perf_evsel *evsel __used, double avg)
  {
  	double total, ratio = 0.0;
  	const char *color;
  
  	total = avg_stats(&runtime_ll_cache_stats[cpu]);
  
  	if (total)
  		ratio = avg / total * 100.0;

  	color = get_ratio_color(GRC_CACHE_MISSES, ratio);

  	fprintf(output, " #  ");
  	color_fprintf(output, color, "%6.2f%%", ratio);
  	fprintf(output, " of all LL-cache hits   ");

  }

  static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)

  {

  	double total, ratio = 0.0;

  	char cpustr[16] = { '\0', };

  	const char *fmt;
  
  	if (csv_output)
  		fmt = "%s%.0f%s%s";
  	else if (big_num)

  		fmt = "%s%'18.0f%s%-25s";

  	else

  		fmt = "%s%18.0f%s%-25s";

  
  	if (no_aggr)

  		sprintf(cpustr, "CPU%*d%s",
  			csv_output ? 0 : -4,

  			evsel_list->cpus->map[cpu], csv_sep);

  	else
  		cpu = 0;

  	fprintf(output, fmt, cpustr, avg, csv_sep, event_name(evsel));

  	if (evsel->cgrp)

  		fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);

  	if (csv_output)
  		return;

  	if (perf_evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS)) {

  		total = avg_stats(&runtime_cycles_stats[cpu]);

  
  		if (total)
  			ratio = avg / total;

  		fprintf(output, " #   %5.2f  insns per cycle        ", ratio);

  		total = avg_stats(&runtime_stalled_cycles_front_stats[cpu]);
  		total = max(total, avg_stats(&runtime_stalled_cycles_back_stats[cpu]));

  
  		if (total && avg) {
  			ratio = total / avg;

  			fprintf(output, "
                                               #   %5.2f  stalled cycles per insn", ratio);

  		}

  	} else if (perf_evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES) &&

  			runtime_branches_stats[cpu].n != 0) {

  		print_branch_misses(cpu, evsel, avg);

  	} else if (
  		evsel->attr.type == PERF_TYPE_HW_CACHE &&
  		evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_L1D |
  					((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
  					((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&

  			runtime_l1_dcache_stats[cpu].n != 0) {

  		print_l1_dcache_misses(cpu, evsel, avg);

  	} else if (
  		evsel->attr.type == PERF_TYPE_HW_CACHE &&
  		evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_L1I |
  					((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
  					((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
  			runtime_l1_icache_stats[cpu].n != 0) {
  		print_l1_icache_misses(cpu, evsel, avg);
  	} else if (
  		evsel->attr.type == PERF_TYPE_HW_CACHE &&
  		evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_DTLB |
  					((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
  					((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
  			runtime_dtlb_cache_stats[cpu].n != 0) {
  		print_dtlb_cache_misses(cpu, evsel, avg);
  	} else if (
  		evsel->attr.type == PERF_TYPE_HW_CACHE &&
  		evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_ITLB |
  					((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
  					((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
  			runtime_itlb_cache_stats[cpu].n != 0) {
  		print_itlb_cache_misses(cpu, evsel, avg);
  	} else if (
  		evsel->attr.type == PERF_TYPE_HW_CACHE &&
  		evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_LL |
  					((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
  					((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
  			runtime_ll_cache_stats[cpu].n != 0) {
  		print_ll_cache_misses(cpu, evsel, avg);

  	} else if (perf_evsel__match(evsel, HARDWARE, HW_CACHE_MISSES) &&
  			runtime_cacherefs_stats[cpu].n != 0) {
  		total = avg_stats(&runtime_cacherefs_stats[cpu]);
  
  		if (total)
  			ratio = avg * 100 / total;

  		fprintf(output, " # %8.3f %% of all cache refs    ", ratio);

  	} else if (perf_evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES_FRONTEND)) {
  		print_stalled_cycles_frontend(cpu, evsel, avg);

  	} else if (perf_evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES_BACKEND)) {

  		print_stalled_cycles_backend(cpu, evsel, avg);

  	} else if (perf_evsel__match(evsel, HARDWARE, HW_CPU_CYCLES)) {

  		total = avg_stats(&runtime_nsecs_stats[cpu]);

  
  		if (total)

  			ratio = 1.0 * avg / total;

  		fprintf(output, " # %8.3f GHz                    ", ratio);

  	} else if (runtime_nsecs_stats[cpu].n != 0) {
  		total = avg_stats(&runtime_nsecs_stats[cpu]);

  
  		if (total)

  			ratio = 1000.0 * avg / total;

  		fprintf(output, " # %8.3f M/sec                  ", ratio);

  	} else {

  		fprintf(output, "                                   ");

  	}

  }

  /*
   * Print out the results of a single counter:

   * aggregated counts in system-wide mode

   */

  static void print_counter_aggr(struct perf_evsel *counter)

  {

  	struct perf_stat *ps = counter->priv;
  	double avg = avg_stats(&ps->res_stats[0]);

  	int scaled = counter->counts->scaled;

  	if (scaled == -1) {

  		fprintf(output, "%*s%s%*s",

  			csv_output ? 0 : 18,

  			counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,

  			csv_sep,
  			csv_output ? 0 : -24,
  			event_name(counter));
  
  		if (counter->cgrp)

  			fprintf(output, "%s%s", csv_sep, counter->cgrp->name);

  		fputc('
  ', output);

  		return;
  	}

  	if (nsec_counter(counter))

  		nsec_printout(-1, counter, avg);

  	else

  		abs_printout(-1, counter, avg);

  	print_noise(counter, avg);

  	if (csv_output) {

  		fputc('
  ', output);

  		return;
  	}

  	if (scaled) {
  		double avg_enabled, avg_running;

  		avg_enabled = avg_stats(&ps->res_stats[1]);
  		avg_running = avg_stats(&ps->res_stats[2]);

  		fprintf(output, " [%5.2f%%]", 100 * avg_running / avg_enabled);

  	}

  	fprintf(output, "
  ");

  }

  /*
   * Print out the results of a single counter:
   * does not use aggregated count in system-wide
   */

  static void print_counter(struct perf_evsel *counter)

  {
  	u64 ena, run, val;
  	int cpu;

  	for (cpu = 0; cpu < evsel_list->cpus->nr; cpu++) {

  		val = counter->counts->cpu[cpu].val;
  		ena = counter->counts->cpu[cpu].ena;
  		run = counter->counts->cpu[cpu].run;

  		if (run == 0 || ena == 0) {

  			fprintf(output, "CPU%*d%s%*s%s%*s",

  				csv_output ? 0 : -4,

  				evsel_list->cpus->map[cpu], csv_sep,

  				csv_output ? 0 : 18,

  				counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
  				csv_sep,

  				csv_output ? 0 : -24,

  				event_name(counter));

  			if (counter->cgrp)

  				fprintf(output, "%s%s",
  					csv_sep, counter->cgrp->name);

  			fputc('
  ', output);

  			continue;
  		}
  
  		if (nsec_counter(counter))
  			nsec_printout(cpu, counter, val);
  		else
  			abs_printout(cpu, counter, val);

  		if (!csv_output) {
  			print_noise(counter, 1.0);

  			if (run != ena)

  				fprintf(output, "  (%.2f%%)",
  					100.0 * run / ena);

  		}

  		fputc('
  ', output);

  	}
  }

  static void print_stat(int argc, const char **argv)
  {

  	struct perf_evsel *counter;
  	int i;

  	fflush(stdout);

  	if (!csv_output) {

  		fprintf(output, "
  ");
  		fprintf(output, " Performance counter stats for ");

  		if(target_pid == -1 && target_tid == -1) {

  			fprintf(output, "\'%s", argv[0]);

  			for (i = 1; i < argc; i++)

  				fprintf(output, " %s", argv[i]);

  		} else if (target_pid != -1)

  			fprintf(output, "process id \'%d", target_pid);

  		else

  			fprintf(output, "thread id \'%d", target_tid);

  		fprintf(output, "\'");

  		if (run_count > 1)

  			fprintf(output, " (%d runs)", run_count);
  		fprintf(output, ":
  
  ");

  	}

  	if (no_aggr) {

  		list_for_each_entry(counter, &evsel_list->entries, node)

  			print_counter(counter);
  	} else {

  		list_for_each_entry(counter, &evsel_list->entries, node)

  			print_counter_aggr(counter);
  	}

  	if (!csv_output) {

  		if (!null_run)

  			fprintf(output, "
  ");
  		fprintf(output, " %17.9f seconds time elapsed",

  				avg_stats(&walltime_nsecs_stats)/1e9);
  		if (run_count > 1) {

  			fprintf(output, "                                        ");

  			print_noise_pct(stddev_stats(&walltime_nsecs_stats),
  					avg_stats(&walltime_nsecs_stats));

  		}

  		fprintf(output, "
  
  ");

  	}

  }

  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;
  
  	signal(signr, SIG_DFL);
  	kill(getpid(), signr);

  }
  
  static const char * const stat_usage[] = {

  	"perf stat [<options>] [<command>]",

  	NULL
  };

  static int stat__set_big_num(const struct option *opt __used,
  			     const char *s __used, int unset)
  {
  	big_num_opt = unset ? 0 : 1;
  	return 0;
  }

  static bool append_file;

  static const struct option options[] = {

  	OPT_CALLBACK('e', "event", &evsel_list, "event",

  		     "event selector. use 'perf list' to list available events",

  		     parse_events_option),

  	OPT_CALLBACK(0, "filter", &evsel_list, "filter",
  		     "event filter", parse_filter),

  	OPT_BOOLEAN('i', "no-inherit", &no_inherit,
  		    "child tasks do not inherit counters"),

  	OPT_INTEGER('p', "pid", &target_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('g', "group", &group,
  		    "put the counters into a counter group"),

  	OPT_BOOLEAN('c', "scale", &scale,

  		    "scale/normalize counters"),

  	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)"),

  	OPT_BOOLEAN('n', "null", &null_run,
  		    "null run - dont start any counters"),

  	OPT_INCR('d', "detailed", &detailed_run,

  		    "detailed run - start a lot of events"),

  	OPT_BOOLEAN('S', "sync", &sync_run,
  		    "call sync() before starting a run"),

  	OPT_CALLBACK_NOOPT('B', "big-num", NULL, NULL, 
  			   "print large numbers with thousands\' separators",
  			   stat__set_big_num),

  	OPT_STRING('C', "cpu", &cpu_list, "cpu",
  		    "list of cpus to monitor in system-wide"),

  	OPT_BOOLEAN('A', "no-aggr", &no_aggr,
  		    "disable CPU count aggregation"),

  	OPT_STRING('x', "field-separator", &csv_sep, "separator",
  		   "print counts with custom separator"),

  	OPT_CALLBACK('G', "cgroup", &evsel_list, "name",
  		     "monitor event in cgroup name only",
  		     parse_cgroups),

  	OPT_STRING('o', "output", &output_name, "file",
  		    "output file name"),
  	OPT_BOOLEAN(0, "append", &append_file, "append to the output file"),

  	OPT_INTEGER(0, "log-fd", &output_fd,
  		    "log output to fd, instead of stderr"),

  	OPT_END()
  };

  /*
   * Add default attributes, if there were no attributes specified or
   * if -d/--detailed, -d -d or -d -d -d is used:
   */
  static int add_default_attributes(void)
  {

  	/* Set attrs if no event is selected and !null_run: */
  	if (null_run)
  		return 0;
  
  	if (!evsel_list->nr_entries) {

  		if (perf_evlist__add_attrs_array(evsel_list, default_attrs) < 0)
  			return -1;

  	}
  
  	/* Detailed events get appended to the event list: */
  
  	if (detailed_run <  1)
  		return 0;
  
  	/* Append detailed run extra attributes: */

  	if (perf_evlist__add_attrs_array(evsel_list, detailed_attrs) < 0)
  		return -1;

  
  	if (detailed_run < 2)
  		return 0;
  
  	/* Append very detailed run extra attributes: */

  	if (perf_evlist__add_attrs_array(evsel_list, very_detailed_attrs) < 0)
  		return -1;

  
  	if (detailed_run < 3)
  		return 0;
  
  	/* Append very, very detailed run extra attributes: */

  	return perf_evlist__add_attrs_array(evsel_list, very_very_detailed_attrs);

  }

  int cmd_stat(int argc, const char **argv, const char *prefix __used)

  {

  	struct perf_evsel *pos;
  	int status = -ENOMEM;

  	const char *mode;

  	setlocale(LC_ALL, "");

  	evsel_list = perf_evlist__new(NULL, NULL);

  	if (evsel_list == NULL)
  		return -ENOMEM;

  	argc = parse_options(argc, argv, options, stat_usage,
  		PARSE_OPT_STOP_AT_NON_OPTION);

  	output = stderr;
  	if (output_name && strcmp(output_name, "-"))
  		output = NULL;

  	if (output_name && output_fd) {
  		fprintf(stderr, "cannot use both --output and --log-fd
  ");
  		usage_with_options(stat_usage, options);
  	}

  	if (!output) {
  		struct timespec tm;
  		mode = append_file ? "a" : "w";
  
  		output = fopen(output_name, mode);
  		if (!output) {
  			perror("failed to create output file");
  			exit(-1);
  		}
  		clock_gettime(CLOCK_REALTIME, &tm);
  		fprintf(output, "# started on %s
  ", ctime(&tm.tv_sec));

  	} else if (output_fd != 2) {
  		mode = append_file ? "a" : "w";
  		output = fdopen(output_fd, mode);
  		if (!output) {
  			perror("Failed opening logfd");
  			return -errno;
  		}

  	}

  	if (csv_sep) {

  		csv_output = true;

  		if (!strcmp(csv_sep, "\\t"))
  			csv_sep = "\t";
  	} else

  		csv_sep = DEFAULT_SEPARATOR;
  
  	/*
  	 * let the spreadsheet do the pretty-printing
  	 */
  	if (csv_output) {

  		/* User explicitly passed -B? */

  		if (big_num_opt == 1) {
  			fprintf(stderr, "-B option not supported with -x
  ");
  			usage_with_options(stat_usage, options);
  		} else /* Nope, so disable big number formatting */
  			big_num = false;
  	} else if (big_num_opt == 0) /* User passed --no-big-num */
  		big_num = false;

  	if (!argc && target_pid == -1 && target_tid == -1)

  		usage_with_options(stat_usage, options);

  	if (run_count <= 0)

  		usage_with_options(stat_usage, options);

  	/* no_aggr, cgroup are for system-wide only */
  	if ((no_aggr || nr_cgroups) && !system_wide) {
  		fprintf(stderr, "both cgroup and no-aggregation "
  			"modes only available in system-wide mode
  ");

  		usage_with_options(stat_usage, options);

  	}

  	if (add_default_attributes())
  		goto out;

  	if (target_pid != -1)
  		target_tid = target_pid;

  	evsel_list->threads = thread_map__new(target_pid, target_tid);
  	if (evsel_list->threads == NULL) {

  		pr_err("Problems finding threads of monitor
  ");
  		usage_with_options(stat_usage, options);
  	}

  	if (system_wide)

  		evsel_list->cpus = cpu_map__new(cpu_list);

  	else

  		evsel_list->cpus = cpu_map__dummy_new();

  	if (evsel_list->cpus == NULL) {

  		perror("failed to parse CPUs map");

  		usage_with_options(stat_usage, options);

  		return -1;
  	}

  	list_for_each_entry(pos, &evsel_list->entries, node) {

  		if (perf_evsel__alloc_stat_priv(pos) < 0 ||

  		    perf_evsel__alloc_counts(pos, evsel_list->cpus->nr) < 0)

  			goto out_free_fd;

  	}

  	/*
  	 * We dont want to block the signals - that would cause
  	 * child tasks to inherit that and Ctrl-C would not work.
  	 * What we want is for Ctrl-C to work in the exec()-ed
  	 * task, but being ignored by perf stat itself:
  	 */

  	atexit(sig_atexit);

  	signal(SIGINT,  skip_signal);
  	signal(SIGALRM, skip_signal);
  	signal(SIGABRT, skip_signal);

  	status = 0;
  	for (run_idx = 0; run_idx < run_count; run_idx++) {
  		if (run_count != 1 && verbose)

  			fprintf(output, "[ perf stat: executing run #%d ... ]
  ",
  				run_idx + 1);

  
  		if (sync_run)
  			sync();

  		status = run_perf_stat(argc, argv);
  	}

  	if (status != -1)
  		print_stat(argc, argv);

  out_free_fd:

  	list_for_each_entry(pos, &evsel_list->entries, node)

  		perf_evsel__free_stat_priv(pos);

  	perf_evlist__delete_maps(evsel_list);

  out:
  	perf_evlist__delete(evsel_list);

  	return status;

  }