/*

   * builtin-top.c
   *
   * Builtin top command: Display a continuously updated profile of
   * any workload, CPU or specific PID.
   *
   * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>

   *		 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@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>
   *
   * Released under the GPL v2. (and only v2, not any later version)

   */

  #include "builtin.h"

  #include "perf.h"

  #include "util/annotate.h"

  #include "util/cache.h"

  #include "util/color.h"

  #include "util/evlist.h"

  #include "util/evsel.h"

  #include "util/session.h"
  #include "util/symbol.h"

  #include "util/thread.h"

  #include "util/thread_map.h"

  #include "util/top.h"

  #include "util/util.h"

  #include <linux/rbtree.h>

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

  #include "util/cpumap.h"

  #include "util/xyarray.h"

  #include "util/sort.h"

  #include "util/debug.h"

  #include <assert.h>
  #include <fcntl.h>

  #include <stdio.h>

  #include <termios.h>
  #include <unistd.h>

  #include <inttypes.h>

  #include <errno.h>

  #include <time.h>
  #include <sched.h>

  
  #include <sys/syscall.h>
  #include <sys/ioctl.h>
  #include <sys/poll.h>
  #include <sys/prctl.h>
  #include <sys/wait.h>
  #include <sys/uio.h>
  #include <sys/mman.h>
  
  #include <linux/unistd.h>
  #include <linux/types.h>

  static struct perf_top top = {
  	.count_filter		= 5,
  	.delay_secs		= 2,

  	.target_pid		= -1,
  	.target_tid		= -1,

  	.freq			= 1000, /* 1 KHz */
  };

  static bool			system_wide			=  false;

  static bool			use_tui, use_stdio;

  static bool			sort_has_symbols;
  
  static bool			dont_use_callchains;
  static char			callchain_default_opt[]		= "fractal,0.5,callee";

  static int			default_interval		=      0;

  static bool			kptr_restrict_warned;

  static bool			vmlinux_warned;

  static bool			inherit				=  false;

  static int			realtime_prio			=      0;

  static bool			group				=  false;

  static bool			sample_id_all_avail		=   true;

  static unsigned int		mmap_pages			=    128;

  static bool			dump_symtab                     =  false;

  static struct winsize		winsize;

  static const char		*sym_filter			=   NULL;

  static int			sym_pcnt_filter			=      5;

  /*
   * Source functions
   */

  void get_term_dimensions(struct winsize *ws)

  {

  	char *s = getenv("LINES");
  
  	if (s != NULL) {
  		ws->ws_row = atoi(s);
  		s = getenv("COLUMNS");
  		if (s != NULL) {
  			ws->ws_col = atoi(s);
  			if (ws->ws_row && ws->ws_col)
  				return;
  		}

  	}

  #ifdef TIOCGWINSZ
  	if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
  	    ws->ws_row && ws->ws_col)
  		return;

  #endif

  	ws->ws_row = 25;
  	ws->ws_col = 80;

  }

  static void update_print_entries(struct winsize *ws)

  {

  	top.print_entries = ws->ws_row;

  	if (top.print_entries > 9)
  		top.print_entries -= 9;

  }
  
  static void sig_winch_handler(int sig __used)
  {

  	get_term_dimensions(&winsize);
  	update_print_entries(&winsize);

  }

  static int parse_source(struct hist_entry *he)

  {
  	struct symbol *sym;

  	struct annotation *notes;

  	struct map *map;

  	int err = -1;

  	if (!he || !he->ms.sym)

  		return -1;

  	sym = he->ms.sym;
  	map = he->ms.map;

  
  	/*
  	 * We can't annotate with just /proc/kallsyms
  	 */

  	if (map->dso->symtab_type == SYMTAB__KALLSYMS) {

  		pr_err("Can't annotate %s: No vmlinux file was found in the "
  		       "path
  ", sym->name);
  		sleep(1);

  		return -1;

  	}

  	notes = symbol__annotation(sym);
  	if (notes->src != NULL) {
  		pthread_mutex_lock(&notes->lock);

  		goto out_assign;
  	}

  	pthread_mutex_lock(&notes->lock);

  	if (symbol__alloc_hist(sym, top.evlist->nr_entries) < 0) {

  		pthread_mutex_unlock(&notes->lock);

  		pr_err("Not enough memory for annotating '%s' symbol!
  ",
  		       sym->name);

  		sleep(1);

  		return err;

  	}

  	err = symbol__annotate(sym, map, 0);

  	if (err == 0) {

  out_assign:

  		top.sym_filter_entry = he;

  	}

  	pthread_mutex_unlock(&notes->lock);

  	return err;

  }

  static void __zero_source_counters(struct hist_entry *he)

  {

  	struct symbol *sym = he->ms.sym;

  	symbol__annotate_zero_histograms(sym);

  }

  static void record_precise_ip(struct hist_entry *he, int counter, u64 ip)

  {

  	struct annotation *notes;
  	struct symbol *sym;

  	if (he == NULL || he->ms.sym == NULL ||

  	    ((top.sym_filter_entry == NULL ||
  	      top.sym_filter_entry->ms.sym != he->ms.sym) && use_browser != 1))

  		return;

  	sym = he->ms.sym;

  	notes = symbol__annotation(sym);
  
  	if (pthread_mutex_trylock(&notes->lock))

  		return;

  	if (notes->src == NULL &&
  	    symbol__alloc_hist(sym, top.evlist->nr_entries) < 0) {
  		pthread_mutex_unlock(&notes->lock);
  		pr_err("Not enough memory for annotating '%s' symbol!
  ",
  		       sym->name);
  		sleep(1);
  		return;
  	}
  
  	ip = he->ms.map->map_ip(he->ms.map, ip);
  	symbol__inc_addr_samples(sym, he->ms.map, counter, ip);

  	pthread_mutex_unlock(&notes->lock);

  }

  static void show_details(struct hist_entry *he)

  {

  	struct annotation *notes;

  	struct symbol *symbol;

  	int more;

  	if (!he)

  		return;

  	symbol = he->ms.sym;

  	notes = symbol__annotation(symbol);
  
  	pthread_mutex_lock(&notes->lock);
  
  	if (notes->src == NULL)
  		goto out_unlock;

  	printf("Showing %s for %s
  ", event_name(top.sym_evsel), symbol->name);

  	printf("  Events  Pcnt (>=%d%%)
  ", sym_pcnt_filter);

  	more = symbol__annotate_printf(symbol, he->ms.map, top.sym_evsel->idx,

  				       0, sym_pcnt_filter, top.print_entries, 4);

  	if (top.zero)
  		symbol__annotate_zero_histogram(symbol, top.sym_evsel->idx);
  	else

  		symbol__annotate_decay_histogram(symbol, top.sym_evsel->idx);

  	if (more != 0)

  		printf("%d lines not displayed, maybe increase display entries [e]
  ", more);

  out_unlock:
  	pthread_mutex_unlock(&notes->lock);

  }

  static const char		CONSOLE_CLEAR[] = "";

  static struct hist_entry *
  	perf_session__add_hist_entry(struct perf_session *session,
  				     struct addr_location *al,
  				     struct perf_sample *sample,
  				     struct perf_evsel *evsel)

  {

  	struct hist_entry *he;
  
  	he = __hists__add_entry(&evsel->hists, al, NULL, sample->period);
  	if (he == NULL)
  		return NULL;
  
  	session->hists.stats.total_period += sample->period;
  	hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
  	return he;

  }

  static void print_sym_table(void)

  {

  	char bf[160];
  	int printed = 0;

  	const int win_width = winsize.ws_col - 1;

  	puts(CONSOLE_CLEAR);

  	perf_top__header_snprintf(&top, bf, sizeof(bf));
  	printf("%s
  ", bf);

  	perf_top__reset_sample_counters(&top);

  	printf("%-*.*s
  ", win_width, win_width, graph_dotted_line);

  	if (top.sym_evsel->hists.stats.nr_lost_warned !=
  	    top.sym_evsel->hists.stats.nr_events[PERF_RECORD_LOST]) {
  		top.sym_evsel->hists.stats.nr_lost_warned =
  			top.sym_evsel->hists.stats.nr_events[PERF_RECORD_LOST];
  		color_fprintf(stdout, PERF_COLOR_RED,
  			      "WARNING: LOST %d chunks, Check IO/CPU overload",
  			      top.sym_evsel->hists.stats.nr_lost_warned);

  		++printed;

  	}

  	if (top.sym_filter_entry) {
  		show_details(top.sym_filter_entry);

  		return;
  	}

  	hists__collapse_resort_threaded(&top.sym_evsel->hists);
  	hists__output_resort_threaded(&top.sym_evsel->hists);

  	hists__decay_entries_threaded(&top.sym_evsel->hists,
  				      top.hide_user_symbols,
  				      top.hide_kernel_symbols);

  	hists__output_recalc_col_len(&top.sym_evsel->hists, winsize.ws_row - 3);

  	putchar('
  ');

  	hists__fprintf(&top.sym_evsel->hists, NULL, false, false,
  		       winsize.ws_row - 4 - printed, win_width, stdout);

  }

  static void prompt_integer(int *target, const char *msg)
  {
  	char *buf = malloc(0), *p;
  	size_t dummy = 0;
  	int tmp;
  
  	fprintf(stdout, "
  %s: ", msg);
  	if (getline(&buf, &dummy, stdin) < 0)
  		return;
  
  	p = strchr(buf, '
  ');
  	if (p)
  		*p = 0;
  
  	p = buf;
  	while(*p) {
  		if (!isdigit(*p))
  			goto out_free;
  		p++;
  	}
  	tmp = strtoul(buf, NULL, 10);
  	*target = tmp;
  out_free:
  	free(buf);
  }
  
  static void prompt_percent(int *target, const char *msg)
  {
  	int tmp = 0;
  
  	prompt_integer(&tmp, msg);
  	if (tmp >= 0 && tmp <= 100)
  		*target = tmp;
  }

  static void prompt_symbol(struct hist_entry **target, const char *msg)

  {
  	char *buf = malloc(0), *p;

  	struct hist_entry *syme = *target, *n, *found = NULL;
  	struct rb_node *next;

  	size_t dummy = 0;
  
  	/* zero counters of active symbol */
  	if (syme) {

  		__zero_source_counters(syme);
  		*target = NULL;

  	}
  
  	fprintf(stdout, "
  %s: ", msg);
  	if (getline(&buf, &dummy, stdin) < 0)
  		goto out_free;
  
  	p = strchr(buf, '
  ');
  	if (p)
  		*p = 0;

  	next = rb_first(&top.sym_evsel->hists.entries);
  	while (next) {
  		n = rb_entry(next, struct hist_entry, rb_node);
  		if (n->ms.sym && !strcmp(buf, n->ms.sym->name)) {
  			found = n;

  			break;
  		}

  		next = rb_next(&n->rb_node);

  	}
  
  	if (!found) {

  		fprintf(stderr, "Sorry, %s is not active.
  ", buf);

  		sleep(1);
  		return;
  	} else
  		parse_source(found);
  
  out_free:
  	free(buf);
  }

  static void print_mapped_keys(void)

  {

  	char *name = NULL;

  	if (top.sym_filter_entry) {

  		struct symbol *sym = top.sym_filter_entry->ms.sym;

  		name = sym->name;
  	}
  
  	fprintf(stdout, "
  Mapped keys:
  ");

  	fprintf(stdout, "\t[d]     display refresh delay.             \t(%d)
  ", top.delay_secs);
  	fprintf(stdout, "\t[e]     display entries (lines).           \t(%d)
  ", top.print_entries);

  	if (top.evlist->nr_entries > 1)
  		fprintf(stdout, "\t[E]     active event counter.              \t(%s)
  ", event_name(top.sym_evsel));

  	fprintf(stdout, "\t[f]     profile display filter (count).    \t(%d)
  ", top.count_filter);

  	fprintf(stdout, "\t[F]     annotate display filter (percent). \t(%d%%)
  ", sym_pcnt_filter);
  	fprintf(stdout, "\t[s]     annotate symbol.                   \t(%s)
  ", name?: "NULL");
  	fprintf(stdout, "\t[S]     stop annotation.
  ");

  	fprintf(stdout,

  		"\t[K]     hide kernel_symbols symbols.     \t(%s)
  ",

  		top.hide_kernel_symbols ? "yes" : "no");

  	fprintf(stdout,
  		"\t[U]     hide user symbols.               \t(%s)
  ",

  		top.hide_user_symbols ? "yes" : "no");
  	fprintf(stdout, "\t[z]     toggle sample zeroing.             \t(%d)
  ", top.zero ? 1 : 0);

  	fprintf(stdout, "\t[qQ]    quit.
  ");
  }
  
  static int key_mapped(int c)
  {
  	switch (c) {
  		case 'd':
  		case 'e':
  		case 'f':
  		case 'z':
  		case 'q':
  		case 'Q':

  		case 'K':
  		case 'U':

  		case 'F':
  		case 's':
  		case 'S':

  			return 1;
  		case 'E':

  			return top.evlist->nr_entries > 1 ? 1 : 0;

  		default:
  			break;

  	}
  
  	return 0;

  }

  static void handle_keypress(int c)

  {

  	if (!key_mapped(c)) {
  		struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
  		struct termios tc, save;
  
  		print_mapped_keys();
  		fprintf(stdout, "
  Enter selection, or unmapped key to continue: ");
  		fflush(stdout);
  
  		tcgetattr(0, &save);
  		tc = save;
  		tc.c_lflag &= ~(ICANON | ECHO);
  		tc.c_cc[VMIN] = 0;
  		tc.c_cc[VTIME] = 0;
  		tcsetattr(0, TCSANOW, &tc);
  
  		poll(&stdin_poll, 1, -1);
  		c = getc(stdin);
  
  		tcsetattr(0, TCSAFLUSH, &save);
  		if (!key_mapped(c))
  			return;
  	}

  	switch (c) {
  		case 'd':

  			prompt_integer(&top.delay_secs, "Enter display delay");
  			if (top.delay_secs < 1)
  				top.delay_secs = 1;

  			break;
  		case 'e':

  			prompt_integer(&top.print_entries, "Enter display entries (lines)");
  			if (top.print_entries == 0) {

  				sig_winch_handler(SIGWINCH);

  				signal(SIGWINCH, sig_winch_handler);
  			} else
  				signal(SIGWINCH, SIG_DFL);

  			break;
  		case 'E':

  			if (top.evlist->nr_entries > 1) {

  				/* Select 0 as the default event: */
  				int counter = 0;

  				fprintf(stderr, "
  Available events:");

  				list_for_each_entry(top.sym_evsel, &top.evlist->entries, node)
  					fprintf(stderr, "
  \t%d %s", top.sym_evsel->idx, event_name(top.sym_evsel));

  				prompt_integer(&counter, "Enter details event counter");

  				if (counter >= top.evlist->nr_entries) {

  					top.sym_evsel = list_entry(top.evlist->entries.next, struct perf_evsel, node);

  					fprintf(stderr, "Sorry, no such event, using %s.
  ", event_name(top.sym_evsel));

  					sleep(1);

  					break;

  				}

  				list_for_each_entry(top.sym_evsel, &top.evlist->entries, node)

  					if (top.sym_evsel->idx == counter)

  						break;

  			} else
  				top.sym_evsel = list_entry(top.evlist->entries.next, struct perf_evsel, node);

  			break;
  		case 'f':

  			prompt_integer(&top.count_filter, "Enter display event count filter");

  			break;
  		case 'F':
  			prompt_percent(&sym_pcnt_filter, "Enter details display event filter (percent)");
  			break;

  		case 'K':

  			top.hide_kernel_symbols = !top.hide_kernel_symbols;

  			break;

  		case 'q':
  		case 'Q':
  			printf("exiting.
  ");

  			if (dump_symtab)

  				perf_session__fprintf_dsos(top.session, stderr);

  			exit(0);
  		case 's':

  			prompt_symbol(&top.sym_filter_entry, "Enter details symbol");

  			break;
  		case 'S':

  			if (!top.sym_filter_entry)

  				break;
  			else {

  				struct hist_entry *syme = top.sym_filter_entry;

  				top.sym_filter_entry = NULL;

  				__zero_source_counters(syme);

  			}
  			break;

  		case 'U':

  			top.hide_user_symbols = !top.hide_user_symbols;

  			break;

  		case 'z':

  			top.zero = !top.zero;

  			break;

  		default:
  			break;

  	}
  }

  static void perf_top__sort_new_samples(void *arg)
  {
  	struct perf_top *t = arg;
  	perf_top__reset_sample_counters(t);
  
  	if (t->evlist->selected != NULL)
  		t->sym_evsel = t->evlist->selected;
  
  	hists__collapse_resort_threaded(&t->sym_evsel->hists);
  	hists__output_resort_threaded(&t->sym_evsel->hists);

  	hists__decay_entries_threaded(&t->sym_evsel->hists,
  				      top.hide_user_symbols,
  				      top.hide_kernel_symbols);

  }

  static void *display_thread_tui(void *arg __used)
  {

  	const char *help = "For a higher level overview, try: perf top --sort comm,dso";
  
  	perf_top__sort_new_samples(&top);
  	perf_evlist__tui_browse_hists(top.evlist, help,
  				      perf_top__sort_new_samples,
  				      &top, top.delay_secs);

  	exit_browser(0);
  	exit(0);
  	return NULL;
  }

  static void *display_thread(void *arg __used)

  {

  	struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };

  	struct termios tc, save;
  	int delay_msecs, c;
  
  	tcgetattr(0, &save);
  	tc = save;
  	tc.c_lflag &= ~(ICANON | ECHO);
  	tc.c_cc[VMIN] = 0;
  	tc.c_cc[VTIME] = 0;

  	pthread__unblock_sigwinch();

  repeat:

  	delay_msecs = top.delay_secs * 1000;

  	tcsetattr(0, TCSANOW, &tc);
  	/* trash return*/
  	getc(stdin);

  	while (1) {

  		print_sym_table();

  		/*
  		 * Either timeout expired or we got an EINTR due to SIGWINCH,
  		 * refresh screen in both cases.
  		 */
  		switch (poll(&stdin_poll, 1, delay_msecs)) {
  		case 0:
  			continue;
  		case -1:
  			if (errno == EINTR)
  				continue;
  			/* Fall trhu */
  		default:
  			goto process_hotkey;
  		}
  	}
  process_hotkey:

  	c = getc(stdin);
  	tcsetattr(0, TCSAFLUSH, &save);

  	handle_keypress(c);

  	goto repeat;

  
  	return NULL;
  }

  /* Tag samples to be skipped. */

  static const char *skip_symbols[] = {

  	"default_idle",

  	"native_safe_halt",

  	"cpu_idle",
  	"enter_idle",
  	"exit_idle",
  	"mwait_idle",

  	"mwait_idle_with_hints",

  	"poll_idle",

  	"ppc64_runlatch_off",
  	"pseries_dedicated_idle_sleep",

  	NULL
  };

  static int symbol_filter(struct map *map __used, struct symbol *sym)

  {

  	const char *name = sym->name;

  	int i;

  	/*
  	 * ppc64 uses function descriptors and appends a '.' to the
  	 * start of every instruction address. Remove it.
  	 */
  	if (name[0] == '.')
  		name++;

  	if (!strcmp(name, "_text") ||
  	    !strcmp(name, "_etext") ||
  	    !strcmp(name, "_sinittext") ||
  	    !strncmp("init_module", name, 11) ||
  	    !strncmp("cleanup_module", name, 14) ||
  	    strstr(name, "_text_start") ||
  	    strstr(name, "_text_end"))

  		return 1;

  	for (i = 0; skip_symbols[i]; i++) {
  		if (!strcmp(skip_symbols[i], name)) {

  			sym->ignore = true;

  			break;
  		}
  	}

  	return 0;
  }

  static void perf_event__process_sample(const union perf_event *event,

  				       struct perf_evsel *evsel,

  				       struct perf_sample *sample,
  				       struct perf_session *session)

  {

  	struct symbol *parent = NULL;

  	u64 ip = event->ip.ip;

  	struct addr_location al;

  	struct machine *machine;

  	int err;

  	u8 origin = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

  	++top.samples;

  	switch (origin) {

  	case PERF_RECORD_MISC_USER:

  		++top.us_samples;
  		if (top.hide_user_symbols)

  			return;

  		machine = perf_session__find_host_machine(session);

  		break;

  	case PERF_RECORD_MISC_KERNEL:

  		++top.kernel_samples;
  		if (top.hide_kernel_symbols)

  			return;

  		machine = perf_session__find_host_machine(session);

  		break;
  	case PERF_RECORD_MISC_GUEST_KERNEL:

  		++top.guest_kernel_samples;

  		machine = perf_session__find_machine(session, event->ip.pid);

  		break;

  	case PERF_RECORD_MISC_GUEST_USER:

  		++top.guest_us_samples;

  		/*
  		 * TODO: we don't process guest user from host side
  		 * except simple counting.
  		 */
  		return;

  	default:
  		return;
  	}

  	if (!machine && perf_guest) {

  		pr_err("Can't find guest [%d]'s kernel information
  ",

  			event->ip.pid);

  		return;
  	}

  	if (event->header.misc & PERF_RECORD_MISC_EXACT_IP)

  		top.exact_samples++;

  	if (perf_event__preprocess_sample(event, session, &al, sample,
  					  symbol_filter) < 0 ||

  	    al.filtered)

  		return;

  	if (!kptr_restrict_warned &&
  	    symbol_conf.kptr_restrict &&
  	    al.cpumode == PERF_RECORD_MISC_KERNEL) {
  		ui__warning(
  "Kernel address maps (/proc/{kallsyms,modules}) are restricted.
  
  "
  "Check /proc/sys/kernel/kptr_restrict.
  
  "
  "Kernel%s samples will not be resolved.
  ",
  			  !RB_EMPTY_ROOT(&al.map->dso->symbols[MAP__FUNCTION]) ?
  			  " modules" : "");
  		if (use_browser <= 0)
  			sleep(5);
  		kptr_restrict_warned = true;
  	}

  	if (al.sym == NULL) {

  		const char *msg = "Kernel samples will not be resolved.
  ";

  		/*
  		 * As we do lazy loading of symtabs we only will know if the
  		 * specified vmlinux file is invalid when we actually have a
  		 * hit in kernel space and then try to load it. So if we get
  		 * here and there are _no_ symbols in the DSO backing the
  		 * kernel map, bail out.
  		 *
  		 * We may never get here, for instance, if we use -K/
  		 * --hide-kernel-symbols, even if the user specifies an
  		 * invalid --vmlinux ;-)
  		 */

  		if (!kptr_restrict_warned && !vmlinux_warned &&
  		    al.map == machine->vmlinux_maps[MAP__FUNCTION] &&

  		    RB_EMPTY_ROOT(&al.map->dso->symbols[MAP__FUNCTION])) {

  			if (symbol_conf.vmlinux_name) {
  				ui__warning("The %s file can't be used.
  %s",
  					    symbol_conf.vmlinux_name, msg);
  			} else {
  				ui__warning("A vmlinux file was not found.
  %s",
  					    msg);
  			}
  
  			if (use_browser <= 0)
  				sleep(5);
  			vmlinux_warned = true;

  		}

  	}

  	if (al.sym == NULL || !al.sym->ignore) {

  		struct hist_entry *he;

  		if ((sort__has_parent || symbol_conf.use_callchain) &&
  		    sample->callchain) {
  			err = perf_session__resolve_callchain(session, al.thread,
  							      sample->callchain, &parent);
  			if (err)
  				return;
  		}

  		he = perf_session__add_hist_entry(session, &al, sample, evsel);
  		if (he == NULL) {
  			pr_err("Problem incrementing symbol period, skipping event
  ");
  			return;

  		}

  		if (symbol_conf.use_callchain) {
  			err = callchain_append(he->callchain, &session->callchain_cursor,
  					       sample->period);
  			if (err)
  				return;
  		}
  
  		if (sort_has_symbols)
  			record_precise_ip(he, evsel->idx, ip);

  	}

  
  	return;

  }

  static void perf_session__mmap_read_idx(struct perf_session *self, int idx)

  {

  	struct perf_sample sample;

  	struct perf_evsel *evsel;

  	union perf_event *event;

  	int ret;

  	while ((event = perf_evlist__mmap_read(top.evlist, idx)) != NULL) {

  		ret = perf_session__parse_sample(self, event, &sample);
  		if (ret) {
  			pr_err("Can't parse sample, err = %d
  ", ret);
  			continue;
  		}

  		evsel = perf_evlist__id2evsel(self->evlist, sample.id);
  		assert(evsel != NULL);

  		if (event->header.type == PERF_RECORD_SAMPLE)

  			perf_event__process_sample(event, evsel, &sample, self);
  		else if (event->header.type < PERF_RECORD_MAX) {
  			hists__inc_nr_events(&evsel->hists, event->header.type);

  			perf_event__process(event, &sample, self);

  		} else
  			++self->hists.stats.nr_unknown_events;

  	}

  }

  static void perf_session__mmap_read(struct perf_session *self)

  {

  	int i;

  	for (i = 0; i < top.evlist->nr_mmaps; i++)
  		perf_session__mmap_read_idx(self, i);

  }

  static void start_counters(struct perf_evlist *evlist)
  {

  	struct perf_evsel *counter, *first;
  
  	first = list_entry(evlist->entries.next, struct perf_evsel, node);

  	list_for_each_entry(counter, &evlist->entries, node) {
  		struct perf_event_attr *attr = &counter->attr;

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

  		attr->sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;

  		if (top.freq) {

  			attr->sample_type |= PERF_SAMPLE_PERIOD;
  			attr->freq	  = 1;

  			attr->sample_freq = top.freq;

  		}

  		if (evlist->nr_entries > 1) {
  			attr->sample_type |= PERF_SAMPLE_ID;
  			attr->read_format |= PERF_FORMAT_ID;
  		}

  		if (symbol_conf.use_callchain)
  			attr->sample_type |= PERF_SAMPLE_CALLCHAIN;

  		attr->mmap = 1;

  		attr->comm = 1;

  		attr->inherit = inherit;

  retry_sample_id:
  		attr->sample_id_all = sample_id_all_avail ? 1 : 0;

  try_again:

  		if (perf_evsel__open(counter, top.evlist->cpus,

  				     top.evlist->threads, group,
  				     group_fd) < 0) {

  			int err = errno;

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

  				ui__error_paranoid();

  				goto out_err;

  			} else if (err == EINVAL && sample_id_all_avail) {
  				/*
  				 * Old kernel, no attr->sample_id_type_all field
  				 */
  				sample_id_all_avail = false;
  				goto retry_sample_id;

  			}

  			/*
  			 * If it's cycles then fall back to hrtimer
  			 * based cpu-clock-tick sw counter, which
  			 * is always available even if no PMU support:
  			 */

  			if (attr->type == PERF_TYPE_HARDWARE &&
  			    attr->config == PERF_COUNT_HW_CPU_CYCLES) {

  				if (verbose)

  					ui__warning("Cycles event not supported,
  "
  						    "trying to fall back to cpu-clock-ticks
  ");

  
  				attr->type = PERF_TYPE_SOFTWARE;
  				attr->config = PERF_COUNT_SW_CPU_CLOCK;
  				goto try_again;
  			}

  			if (err == ENOENT) {
  				ui__warning("The %s event is not supported.
  ",
  					    event_name(counter));
  				goto out_err;
  			}

  			ui__warning("The sys_perf_event_open() syscall "
  				    "returned with %d (%s).  /bin/dmesg "
  				    "may provide additional information.
  "
  				    "No CONFIG_PERF_EVENTS=y kernel support "
  				    "configured?
  ", err, strerror(err));
  			goto out_err;

  		}

  	}

  	if (perf_evlist__mmap(evlist, mmap_pages, false) < 0) {
  		ui__warning("Failed to mmap with %d (%s)
  ",
  			    errno, strerror(errno));
  		goto out_err;
  	}
  
  	return;
  
  out_err:
  	exit_browser(0);
  	exit(0);

  }

  static int setup_sample_type(void)
  {
  	if (!sort_has_symbols) {
  		if (symbol_conf.use_callchain) {
  			ui__warning("Selected -g but \"sym\" not present in --sort/-s.");
  			return -EINVAL;
  		}
  	} else if (!dont_use_callchains && callchain_param.mode != CHAIN_NONE) {
  		if (callchain_register_param(&callchain_param) < 0) {
  			ui__warning("Can't register callchain params.
  ");
  			return -EINVAL;
  		}
  	}
  
  	return 0;
  }

  static int __cmd_top(void)
  {
  	pthread_t thread;

  	int ret;

  	/*

  	 * FIXME: perf_session__new should allow passing a O_MMAP, so that all this
  	 * mmap reading, etc is encapsulated in it. Use O_WRONLY for now.

  	 */

  	top.session = perf_session__new(NULL, O_WRONLY, false, false, NULL);
  	if (top.session == NULL)

  		return -ENOMEM;

  	ret = setup_sample_type();
  	if (ret)
  		goto out_delete;

  	if (top.target_tid != -1)

  		perf_event__synthesize_thread_map(top.evlist->threads,

  						  perf_event__process, top.session);

  	else

  		perf_event__synthesize_threads(perf_event__process, top.session);

  	start_counters(top.evlist);

  	top.session->evlist = top.evlist;
  	perf_session__update_sample_type(top.session);

  	/* Wait for a minimal set of events before starting the snapshot */

  	poll(top.evlist->pollfd, top.evlist->nr_fds, 100);

  	perf_session__mmap_read(top.session);

  	if (pthread_create(&thread, NULL, (use_browser > 0 ? display_thread_tui :

  							     display_thread), NULL)) {

  		printf("Could not create display thread.
  ");
  		exit(-1);
  	}
  
  	if (realtime_prio) {
  		struct sched_param param;
  
  		param.sched_priority = realtime_prio;
  		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
  			printf("Could not set realtime priority.
  ");
  			exit(-1);
  		}
  	}
  
  	while (1) {

  		u64 hits = top.samples;

  		perf_session__mmap_read(top.session);

  		if (hits == top.samples)
  			ret = poll(top.evlist->pollfd, top.evlist->nr_fds, 100);

  	}

  out_delete:
  	perf_session__delete(top.session);
  	top.session = NULL;
  
  	return 0;
  }
  
  static int
  parse_callchain_opt(const struct option *opt __used, const char *arg,
  		    int unset)
  {
  	char *tok, *tok2;
  	char *endptr;
  
  	/*
  	 * --no-call-graph
  	 */
  	if (unset) {
  		dont_use_callchains = true;
  		return 0;
  	}
  
  	symbol_conf.use_callchain = true;
  
  	if (!arg)
  		return 0;
  
  	tok = strtok((char *)arg, ",");
  	if (!tok)
  		return -1;
  
  	/* get the output mode */
  	if (!strncmp(tok, "graph", strlen(arg)))
  		callchain_param.mode = CHAIN_GRAPH_ABS;
  
  	else if (!strncmp(tok, "flat", strlen(arg)))
  		callchain_param.mode = CHAIN_FLAT;
  
  	else if (!strncmp(tok, "fractal", strlen(arg)))
  		callchain_param.mode = CHAIN_GRAPH_REL;
  
  	else if (!strncmp(tok, "none", strlen(arg))) {
  		callchain_param.mode = CHAIN_NONE;
  		symbol_conf.use_callchain = false;
  
  		return 0;
  	}
  
  	else
  		return -1;
  
  	/* get the min percentage */
  	tok = strtok(NULL, ",");
  	if (!tok)
  		goto setup;
  
  	callchain_param.min_percent = strtod(tok, &endptr);
  	if (tok == endptr)
  		return -1;
  
  	/* get the print limit */
  	tok2 = strtok(NULL, ",");
  	if (!tok2)
  		goto setup;
  
  	if (tok2[0] != 'c') {
  		callchain_param.print_limit = strtod(tok2, &endptr);
  		tok2 = strtok(NULL, ",");
  		if (!tok2)
  			goto setup;
  	}
  
  	/* get the call chain order */
  	if (!strcmp(tok2, "caller"))
  		callchain_param.order = ORDER_CALLER;
  	else if (!strcmp(tok2, "callee"))
  		callchain_param.order = ORDER_CALLEE;
  	else
  		return -1;
  setup:
  	if (callchain_register_param(&callchain_param) < 0) {
  		fprintf(stderr, "Can't register callchain params
  ");
  		return -1;
  	}

  	return 0;
  }

  
  static const char * const top_usage[] = {
  	"perf top [<options>]",
  	NULL
  };

  static const struct option options[] = {

  	OPT_CALLBACK('e', "event", &top.evlist, "event",

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

  		     parse_events_option),

  	OPT_INTEGER('c', "count", &default_interval,
  		    "event period to sample"),

  	OPT_INTEGER('p', "pid", &top.target_pid,

  		    "profile events on existing process id"),

  	OPT_INTEGER('t', "tid", &top.target_tid,

  		    "profile events on existing thread id"),

  	OPT_BOOLEAN('a', "all-cpus", &system_wide,
  			    "system-wide collection from all CPUs"),

  	OPT_STRING('C', "cpu", &top.cpu_list, "cpu",

  		    "list of cpus to monitor"),

  	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
  		   "file", "vmlinux pathname"),

  	OPT_BOOLEAN('K', "hide_kernel_symbols", &top.hide_kernel_symbols,

  		    "hide kernel symbols"),

  	OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),

  	OPT_INTEGER('r', "realtime", &realtime_prio,
  		    "collect data with this RT SCHED_FIFO priority"),

  	OPT_INTEGER('d', "delay", &top.delay_secs,

  		    "number of seconds to delay between refreshes"),
  	OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
  			    "dump the symbol table used for profiling"),

  	OPT_INTEGER('f', "count-filter", &top.count_filter,

  		    "only display functions with more events than this"),
  	OPT_BOOLEAN('g', "group", &group,
  			    "put the counters into a counter group"),

  	OPT_BOOLEAN('i', "inherit", &inherit,
  		    "child tasks inherit counters"),

  	OPT_STRING(0, "sym-annotate", &sym_filter, "symbol name",

  		    "symbol to annotate"),

  	OPT_BOOLEAN('z', "zero", &top.zero,

  		    "zero history across updates"),

  	OPT_INTEGER('F', "freq", &top.freq,

  		    "profile at this frequency"),

  	OPT_INTEGER('E', "entries", &top.print_entries,

  		    "display this many functions"),

  	OPT_BOOLEAN('U', "hide_user_symbols", &top.hide_user_symbols,

  		    "hide user symbols"),

  	OPT_BOOLEAN(0, "tui", &use_tui, "Use the TUI interface"),
  	OPT_BOOLEAN(0, "stdio", &use_stdio, "Use the stdio interface"),

  	OPT_INCR('v', "verbose", &verbose,

  		    "be more verbose (show counter open errors, etc)"),

  	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
  		   "sort by key(s): pid, comm, dso, symbol, parent"),
  	OPT_BOOLEAN('n', "show-nr-samples", &symbol_conf.show_nr_samples,
  		    "Show a column with the number of samples"),

  	OPT_CALLBACK_DEFAULT('G', "call-graph", NULL, "output_type,min_percent, call_order",
  		     "Display callchains using output_type (graph, flat, fractal, or none), min percent threshold and callchain order. "
  		     "Default: fractal,0.5,callee", &parse_callchain_opt,
  		     callchain_default_opt),

  	OPT_BOOLEAN(0, "show-total-period", &symbol_conf.show_total_period,
  		    "Show a column with the sum of periods"),
  	OPT_STRING(0, "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
  		   "only consider symbols in these dsos"),
  	OPT_STRING(0, "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
  		   "only consider symbols in these comms"),
  	OPT_STRING(0, "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
  		   "only consider these symbols"),

  	OPT_BOOLEAN(0, "source", &symbol_conf.annotate_src,
  		    "Interleave source code with assembly code (default)"),
  	OPT_BOOLEAN(0, "asm-raw", &symbol_conf.annotate_asm_raw,
  		    "Display raw encoding of assembly instructions (default)"),
  	OPT_STRING('M', "disassembler-style", &disassembler_style, "disassembler style",
  		   "Specify disassembler style (e.g. -M intel for intel syntax)"),

  	OPT_END()
  };

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

  {

  	struct perf_evsel *pos;
  	int status = -ENOMEM;

  	top.evlist = perf_evlist__new(NULL, NULL);
  	if (top.evlist == NULL)

  		return -ENOMEM;

  	symbol_conf.exclude_other = false;

  	argc = parse_options(argc, argv, options, top_usage, 0);
  	if (argc)
  		usage_with_options(top_usage, options);

  	if (sort_order == default_sort_order)
  		sort_order = "dso,symbol";
  
  	setup_sorting(top_usage, options);

  	if (use_stdio)
  		use_browser = 0;
  	else if (use_tui)
  		use_browser = 1;
  
  	setup_browser(false);

  	/* CPU and PID are mutually exclusive */

  	if (top.target_tid > 0 && top.cpu_list) {

  		printf("WARNING: PID switch overriding CPU
  ");
  		sleep(1);

  		top.cpu_list = NULL;

  	}

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

  	if (perf_evlist__create_maps(top.evlist, top.target_pid,
  				     top.target_tid, top.cpu_list) < 0)

  		usage_with_options(top_usage, options);

  	if (!top.evlist->nr_entries &&
  	    perf_evlist__add_default(top.evlist) < 0) {

  		pr_err("Not enough memory for event selector list
  ");
  		return -ENOMEM;
  	}

  	if (top.delay_secs < 1)
  		top.delay_secs = 1;

  	/*
  	 * User specified count overrides default frequency.
  	 */
  	if (default_interval)

  		top.freq = 0;
  	else if (top.freq) {
  		default_interval = top.freq;

  	} else {
  		fprintf(stderr, "frequency and count are zero, aborting
  ");
  		exit(EXIT_FAILURE);
  	}

  	list_for_each_entry(pos, &top.evlist->entries, node) {
  		if (perf_evsel__alloc_fd(pos, top.evlist->cpus->nr,
  					 top.evlist->threads->nr) < 0)

  			goto out_free_fd;
  		/*
  		 * Fill in the ones not specifically initialized via -c:
  		 */
  		if (pos->attr.sample_period)
  			continue;
  
  		pos->attr.sample_period = default_interval;
  	}

  	if (perf_evlist__alloc_pollfd(top.evlist) < 0 ||
  	    perf_evlist__alloc_mmap(top.evlist) < 0)

  		goto out_free_fd;

  	top.sym_evsel = list_entry(top.evlist->entries.next, struct perf_evsel, node);

  	symbol_conf.priv_size = sizeof(struct annotation);

  
  	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
  	if (symbol__init() < 0)
  		return -1;

  	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", stdout);
  	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", stdout);
  	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", stdout);

  	/*
  	 * Avoid annotation data structures overhead when symbols aren't on the
  	 * sort list.
  	 */
  	sort_has_symbols = sort_sym.list.next != NULL;

  	get_term_dimensions(&winsize);

  	if (top.print_entries == 0) {

  		update_print_entries(&winsize);

  		signal(SIGWINCH, sig_winch_handler);
  	}

  	status = __cmd_top();
  out_free_fd:

  	perf_evlist__delete(top.evlist);

  
  	return status;

  }