Merge tag 'batman-adv-for-davem' of git://git.open-mesh.org/linux-merge

[mirror_ubuntu-bionic-kernel.git] / tools / perf / builtin-top.c

/*
 * 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>


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 perf_top__update_print_entries(struct perf_top *top)
{
        if (top->print_entries > 9)
                top->print_entries -= 9;
}

static void perf_top__sig_winch(int sig __used, siginfo_t *info __used, void *arg)
{
        struct perf_top *top = arg;

        get_term_dimensions(&top->winsize);
        if (!top->print_entries
            || (top->print_entries+4) > top->winsize.ws_row) {
                top->print_entries = top->winsize.ws_row;
        } else {
                top->print_entries += 4;
                top->winsize.ws_row = top->print_entries;
        }
        perf_top__update_print_entries(top);
}

static int perf_top__parse_source(struct perf_top *top, 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\n", 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) < 0) {
                pthread_mutex_unlock(&notes->lock);
                pr_err("Not enough memory for annotating '%s' symbol!\n",
                       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 perf_top__record_precise_ip(struct perf_top *top,
                                        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) < 0) {
                pthread_mutex_unlock(&notes->lock);
                pr_err("Not enough memory for annotating '%s' symbol!\n",
                       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 perf_top__show_details(struct perf_top *top)
{
        struct hist_entry *he = top->sym_filter_entry;
        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\n", event_name(top->sym_evsel), symbol->name);
        printf("  Events  Pcnt (>=%d%%)\n", top->sym_pcnt_filter);

        more = symbol__annotate_printf(symbol, he->ms.map, top->sym_evsel->idx,
                                       0, top->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]\n", more);
out_unlock:
        pthread_mutex_unlock(&notes->lock);
}

static const char               CONSOLE_CLEAR[] = "\e[H\e[2J";

static struct hist_entry *perf_evsel__add_hist_entry(struct perf_evsel *evsel,
                                                     struct addr_location *al,
                                                     struct perf_sample *sample)
{
        struct hist_entry *he;

        he = __hists__add_entry(&evsel->hists, al, NULL, sample->period);
        if (he == NULL)
                return NULL;

        hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
        return he;
}

static void perf_top__print_sym_table(struct perf_top *top)
{
        char bf[160];
        int printed = 0;
        const int win_width = top->winsize.ws_col - 1;

        puts(CONSOLE_CLEAR);

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

        perf_top__reset_sample_counters(top);

        printf("%-*.*s\n", 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) {
                perf_top__show_details(top);
                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,
                                     top->winsize.ws_row - 3);
        putchar('\n');
        hists__fprintf(&top->sym_evsel->hists, NULL, false, false,
                       top->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, "\n%s: ", msg);
        if (getline(&buf, &dummy, stdin) < 0)
                return;

        p = strchr(buf, '\n');
        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 perf_top__prompt_symbol(struct perf_top *top, const char *msg)
{
        char *buf = malloc(0), *p;
        struct hist_entry *syme = top->sym_filter_entry, *n, *found = NULL;
        struct rb_node *next;
        size_t dummy = 0;

        /* zero counters of active symbol */
        if (syme) {
                __zero_source_counters(syme);
                top->sym_filter_entry = NULL;
        }

        fprintf(stdout, "\n%s: ", msg);
        if (getline(&buf, &dummy, stdin) < 0)
                goto out_free;

        p = strchr(buf, '\n');
        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.\n", buf);
                sleep(1);
        } else
                perf_top__parse_source(top, found);

out_free:
        free(buf);
}

static void perf_top__print_mapped_keys(struct perf_top *top)
{
        char *name = NULL;

        if (top->sym_filter_entry) {
                struct symbol *sym = top->sym_filter_entry->ms.sym;
                name = sym->name;
        }

        fprintf(stdout, "\nMapped keys:\n");
        fprintf(stdout, "\t[d]     display refresh delay.             \t(%d)\n", top->delay_secs);
        fprintf(stdout, "\t[e]     display entries (lines).           \t(%d)\n", top->print_entries);

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

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

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

        fprintf(stdout,
                "\t[K]     hide kernel_symbols symbols.     \t(%s)\n",
                top->hide_kernel_symbols ? "yes" : "no");
        fprintf(stdout,
                "\t[U]     hide user symbols.               \t(%s)\n",
                top->hide_user_symbols ? "yes" : "no");
        fprintf(stdout, "\t[z]     toggle sample zeroing.             \t(%d)\n", top->zero ? 1 : 0);
        fprintf(stdout, "\t[qQ]    quit.\n");
}

static int perf_top__key_mapped(struct perf_top *top, 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 perf_top__handle_keypress(struct perf_top *top, int c)
{
        if (!perf_top__key_mapped(top, c)) {
                struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
                struct termios tc, save;

                perf_top__print_mapped_keys(top);
                fprintf(stdout, "\nEnter 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 (!perf_top__key_mapped(top, 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) {
                                struct sigaction act = {
                                        .sa_sigaction = perf_top__sig_winch,
                                        .sa_flags     = SA_SIGINFO,
                                };
                                perf_top__sig_winch(SIGWINCH, NULL, top);
                                sigaction(SIGWINCH, &act, NULL);
                        } else {
                                perf_top__sig_winch(SIGWINCH, NULL, top);
                                signal(SIGWINCH, SIG_DFL);
                        }
                        break;
                case 'E':
                        if (top->evlist->nr_entries > 1) {
                                /* Select 0 as the default event: */
                                int counter = 0;

                                fprintf(stderr, "\nAvailable events:");

                                list_for_each_entry(top->sym_evsel, &top->evlist->entries, node)
                                        fprintf(stderr, "\n\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.\n", 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(&top->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.\n");
                        if (top->dump_symtab)
                                perf_session__fprintf_dsos(top->session, stderr);
                        exit(0);
                case 's':
                        perf_top__prompt_symbol(top, "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,
                                      t->hide_user_symbols,
                                      t->hide_kernel_symbols);
}

static void *display_thread_tui(void *arg)
{
        struct perf_top *top = arg;
        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)
{
        struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
        struct termios tc, save;
        struct perf_top *top = arg;
        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) {
                perf_top__print_sym_table(top);
                /*
                 * 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);

        perf_top__handle_keypress(top, 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(struct perf_tool *tool,
                                       const union perf_event *event,
                                       struct perf_evsel *evsel,
                                       struct perf_sample *sample,
                                       struct machine *machine)
{
        struct perf_top *top = container_of(tool, struct perf_top, tool);
        struct symbol *parent = NULL;
        u64 ip = event->ip.ip;
        struct addr_location al;
        int err;

        if (!machine && perf_guest) {
                pr_err("Can't find guest [%d]'s kernel information\n",
                        event->ip.pid);
                return;
        }

        if (event->header.misc & PERF_RECORD_MISC_EXACT_IP)
                top->exact_samples++;

        if (perf_event__preprocess_sample(event, machine, &al, sample,
                                          symbol_filter) < 0 ||
            al.filtered)
                return;

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

        if (al.sym == NULL) {
                const char *msg = "Kernel samples will not be resolved.\n";
                /*
                 * 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 (!top->kptr_restrict_warned && !top->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.\n%s",
                                            symbol_conf.vmlinux_name, msg);
                        } else {
                                ui__warning("A vmlinux file was not found.\n%s",
                                            msg);
                        }

                        if (use_browser <= 0)
                                sleep(5);
                        top->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 = machine__resolve_callchain(machine, evsel, al.thread,
                                                         sample->callchain, &parent);
                        if (err)
                                return;
                }

                he = perf_evsel__add_hist_entry(evsel, &al, sample);
                if (he == NULL) {
                        pr_err("Problem incrementing symbol period, skipping event\n");
                        return;
                }

                if (symbol_conf.use_callchain) {
                        err = callchain_append(he->callchain, &evsel->hists.callchain_cursor,
                                               sample->period);
                        if (err)
                                return;
                }

                if (top->sort_has_symbols)
                        perf_top__record_precise_ip(top, he, evsel->idx, ip);
        }

        return;
}

static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
{
        struct perf_sample sample;
        struct perf_evsel *evsel;
        struct perf_session *session = top->session;
        union perf_event *event;
        struct machine *machine;
        u8 origin;
        int ret;

        while ((event = perf_evlist__mmap_read(top->evlist, idx)) != NULL) {
                ret = perf_session__parse_sample(session, event, &sample);
                if (ret) {
                        pr_err("Can't parse sample, err = %d\n", ret);
                        continue;
                }

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

                origin = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

                if (event->header.type == PERF_RECORD_SAMPLE)
                        ++top->samples;

                switch (origin) {
                case PERF_RECORD_MISC_USER:
                        ++top->us_samples;
                        if (top->hide_user_symbols)
                                continue;
                        machine = perf_session__find_host_machine(session);
                        break;
                case PERF_RECORD_MISC_KERNEL:
                        ++top->kernel_samples;
                        if (top->hide_kernel_symbols)
                                continue;
                        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.
                         */
                        /* Fall thru */
                default:
                        continue;
                }


                if (event->header.type == PERF_RECORD_SAMPLE) {
                        perf_event__process_sample(&top->tool, event, evsel,
                                                   &sample, machine);
                } else if (event->header.type < PERF_RECORD_MAX) {
                        hists__inc_nr_events(&evsel->hists, event->header.type);
                        perf_event__process(&top->tool, event, &sample, machine);
                } else
                        ++session->hists.stats.nr_unknown_events;
        }
}

static void perf_top__mmap_read(struct perf_top *top)
{
        int i;

        for (i = 0; i < top->evlist->nr_mmaps; i++)
                perf_top__mmap_read_idx(top, i);
}

static void perf_top__start_counters(struct perf_top *top)
{
        struct perf_evsel *counter, *first;
        struct perf_evlist *evlist = top->evlist;

        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 (top->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 = top->inherit;
fallback_missing_features:
                if (top->exclude_guest_missing)
                        attr->exclude_guest = attr->exclude_host = 0;
retry_sample_id:
                attr->sample_id_all = top->sample_id_all_avail ? 1 : 0;
try_again:
                if (perf_evsel__open(counter, top->evlist->cpus,
                                     top->evlist->threads, top->group,
                                     group_fd) < 0) {
                        int err = errno;

                        if (err == EPERM || err == EACCES) {
                                ui__error_paranoid();
                                goto out_err;
                        } else if (err == EINVAL) {
                                if (!top->exclude_guest_missing &&
                                    (attr->exclude_guest || attr->exclude_host)) {
                                        pr_debug("Old kernel, cannot exclude "
                                                 "guest or host samples.\n");
                                        top->exclude_guest_missing = true;
                                        goto fallback_missing_features;
                                } else if (top->sample_id_all_avail) {
                                        /*
                                         * Old kernel, no attr->sample_id_type_all field
                                         */
                                        top->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,\n"
                                                    "trying to fall back to cpu-clock-ticks\n");

                                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.\n",
                                            event_name(counter));
                                goto out_err;
                        } else if (err == EMFILE) {
                                ui__warning("Too many events are opened.\n"
                                            "Try again after reducing the number of events\n");
                                goto out_err;
                        }

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

        if (perf_evlist__mmap(evlist, top->mmap_pages, false) < 0) {
                ui__warning("Failed to mmap with %d (%s)\n",
                            errno, strerror(errno));
                goto out_err;
        }

        return;

out_err:
        exit_browser(0);
        exit(0);
}

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

        return 0;
}

static int __cmd_top(struct perf_top *top)
{
        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 = perf_top__setup_sample_type(top);
        if (ret)
                goto out_delete;

        if (top->target_tid != -1)
                perf_event__synthesize_thread_map(&top->tool, top->evlist->threads,
                                                  perf_event__process,
                                                  &top->session->host_machine);
        else
                perf_event__synthesize_threads(&top->tool, perf_event__process,
                                               &top->session->host_machine);
        perf_top__start_counters(top);
        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_top__mmap_read(top);

        if (pthread_create(&thread, NULL, (use_browser > 0 ? display_thread_tui :
                                                            display_thread), top)) {
                printf("Could not create display thread.\n");
                exit(-1);
        }

        if (top->realtime_prio) {
                struct sched_param param;

                param.sched_priority = top->realtime_prio;
                if (sched_setscheduler(0, SCHED_FIFO, &param)) {
                        printf("Could not set realtime priority.\n");
                        exit(-1);
                }
        }

        while (1) {
                u64 hits = top->samples;

                perf_top__mmap_read(top);

                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, const char *arg, int unset)
{
        struct perf_top *top = (struct perf_top *)opt->value;
        char *tok, *tok2;
        char *endptr;

        /*
         * --no-call-graph
         */
        if (unset) {
                top->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\n");
                return -1;
        }
        return 0;
}

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

int cmd_top(int argc, const char **argv, const char *prefix __used)
{
        struct perf_evsel *pos;
        int status = -ENOMEM;
        struct perf_top top = {
                .count_filter        = 5,
                .delay_secs          = 2,
                .target_pid          = -1,
                .target_tid          = -1,
                .freq                = 1000, /* 1 KHz */
                .sample_id_all_avail = true,
                .mmap_pages          = 128,
                .sym_pcnt_filter     = 5,
        };
        char callchain_default_opt[] = "fractal,0.5,callee";
        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", &top.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", &top.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", &top.mmap_pages, "number of mmap data pages"),
        OPT_INTEGER('r', "realtime", &top.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", &top.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", &top.group,
                            "put the counters into a counter group"),
        OPT_BOOLEAN('i', "inherit", &top.inherit,
                    "child tasks inherit counters"),
        OPT_STRING(0, "sym-annotate", &top.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", &top.use_tui, "Use the TUI interface"),
        OPT_BOOLEAN(0, "stdio", &top.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", &top, "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()
        };

        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 (top.use_stdio)
                use_browser = 0;
        else if (top.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\n");
                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\n");
                return -ENOMEM;
        }

        symbol_conf.nr_events = top.evlist->nr_entries;

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

        /*
         * User specified count overrides default frequency.
         */
        if (top.default_interval)
                top.freq = 0;
        else if (top.freq) {
                top.default_interval = top.freq;
        } else {
                fprintf(stderr, "frequency and count are zero, aborting\n");
                exit(EXIT_FAILURE);
        }

        list_for_each_entry(pos, &top.evlist->entries, node) {
                /*
                 * Fill in the ones not specifically initialized via -c:
                 */
                if (!pos->attr.sample_period)
                        pos->attr.sample_period = top.default_interval;
        }

        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.
         */
        top.sort_has_symbols = sort_sym.list.next != NULL;

        get_term_dimensions(&top.winsize);
        if (top.print_entries == 0) {
                struct sigaction act = {
                        .sa_sigaction = perf_top__sig_winch,
                        .sa_flags     = SA_SIGINFO,
                };
                perf_top__update_print_entries(&top);
                sigaction(SIGWINCH, &act, NULL);
        }

        status = __cmd_top(&top);

        perf_evlist__delete(top.evlist);

        return status;
}