builtin-top.c

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/*
 * 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/config.h"
#include "util/color.h"
#include "util/drv_configs.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/event.h"
#include "util/machine.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/thread_map.h"
#include "util/top.h"
#include <linux/rbtree.h>
#include <subcmd/parse-options.h>
#include "util/parse-events.h"
#include "util/cpumap.h"
#include "util/xyarray.h"
#include "util/sort.h"
#include "util/term.h"
#include "util/intlist.h"
#include "util/parse-branch-options.h"
#include "arch/common.h"

#include "util/debug.h"

#include <assert.h>
#include <elf.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 <signal.h>

#include <sys/syscall.h>
#include <sys/ioctl.h>
#include <poll.h>
#include <sys/prctl.h>
#include <sys/wait.h>
#include <sys/uio.h>
#include <sys/utsname.h>
#include <sys/mman.h>

#include <linux/stringify.h>
#include <linux/time64.h>
#include <linux/types.h>

#include "sane_ctype.h"

static volatile int done;
static volatile int resize;

#define HEADER_LINE_NR  5

static void perf_top__update_print_entries(struct perf_top *top)
{
    top->print_entries = top->winsize.ws_row - HEADER_LINE_NR;
}

static void winch_sig(int sig __maybe_unused)
{
    resize = 1;
}

static void perf_top__resize(struct perf_top *top)
{
    get_term_dimensions(&top->winsize);
    perf_top__update_print_entries(top);
}

static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he)
{
    struct perf_evsel *evsel = hists_to_evsel(he->hists);
    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 == DSO_BINARY_TYPE__KALLSYMS &&
        !dso__is_kcore(map->dso)) {
        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);
    pthread_mutex_lock(&notes->lock);

    if (!symbol__hists(sym, top->evlist->nr_entries)) {
        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, evsel, 0, &top->annotation_opts, NULL);
    if (err == 0) {
        top->sym_filter_entry = he;
    } else {
        char msg[BUFSIZ];
        symbol__strerror_disassemble(sym, map, err, msg, sizeof(msg));
        pr_err("Couldn't annotate %s: %s\n", sym->name, msg);
    }

    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 ui__warn_map_erange(struct map *map, struct symbol *sym, u64 ip)
{
    struct utsname uts;
    int err = uname(&uts);

    ui__warning("Out of bounds address found:\n\n"
            "Addr:   %" PRIx64 "\n"
            "DSO:    %s %c\n"
            "Map:    %" PRIx64 "-%" PRIx64 "\n"
            "Symbol: %" PRIx64 "-%" PRIx64 " %c %s\n"
            "Arch:   %s\n"
            "Kernel: %s\n"
            "Tools:  %s\n\n"
            "Not all samples will be on the annotation output.\n\n"
            "Please report to linux-kernel@vger.kernel.org\n",
            ip, map->dso->long_name, dso__symtab_origin(map->dso),
            map->start, map->end, sym->start, sym->end,
            sym->binding == STB_GLOBAL ? 'g' :
            sym->binding == STB_LOCAL  ? 'l' : 'w', sym->name,
            err ? "[unknown]" : uts.machine,
            err ? "[unknown]" : uts.release, perf_version_string);
    if (use_browser <= 0)
        sleep(5);

    map->erange_warned = true;
}

static void perf_top__record_precise_ip(struct perf_top *top,
                    struct hist_entry *he,
                    struct perf_sample *sample,
                    struct perf_evsel *evsel, u64 ip)
{
    struct annotation *notes;
    struct symbol *sym = he->ms.sym;
    int err = 0;

    if (sym == NULL || (use_browser == 0 &&
                (top->sym_filter_entry == NULL ||
                 top->sym_filter_entry->ms.sym != sym)))
        return;

    notes = symbol__annotation(sym);

    if (pthread_mutex_trylock(&notes->lock))
        return;

    err = hist_entry__inc_addr_samples(he, sample, evsel, ip);

    pthread_mutex_unlock(&notes->lock);

    if (unlikely(err)) {
        /*
         * This function is now called with he->hists->lock held.
         * Release it before going to sleep.
         */
        pthread_mutex_unlock(&he->hists->lock);

        if (err == -ERANGE && !he->ms.map->erange_warned)
            ui__warn_map_erange(he->ms.map, sym, ip);
        else if (err == -ENOMEM) {
            pr_err("Not enough memory for annotating '%s' symbol!\n",
                   sym->name);
            sleep(1);
        }

        pthread_mutex_lock(&he->hists->lock);
    }
}

static void perf_top__show_details(struct perf_top *top)
{
    struct hist_entry *he = top->sym_filter_entry;
    struct perf_evsel *evsel = hists_to_evsel(he->hists);
    struct annotation *notes;
    struct symbol *symbol;
    int more;

    if (!he)
        return;

    symbol = he->ms.sym;
    notes = symbol__annotation(symbol);

    pthread_mutex_lock(&notes->lock);

    symbol__calc_percent(symbol, evsel);

    if (notes->src == NULL)
        goto out_unlock;

    printf("Showing %s for %s\n", perf_evsel__name(top->sym_evsel), symbol->name);
    printf("  Events  Pcnt (>=%d%%)\n", top->annotation_opts.min_pcnt);

    more = symbol__annotate_printf(symbol, he->ms.map, top->sym_evsel, &top->annotation_opts);

    if (top->evlist->enabled) {
        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 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;
    struct perf_evsel *evsel = top->sym_evsel;
    struct hists *hists = evsel__hists(evsel);

    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->record_opts.overwrite &&
        (hists->stats.nr_lost_warned !=
        hists->stats.nr_events[PERF_RECORD_LOST])) {
        hists->stats.nr_lost_warned =
                  hists->stats.nr_events[PERF_RECORD_LOST];
        color_fprintf(stdout, PERF_COLOR_RED,
                  "WARNING: LOST %d chunks, Check IO/CPU overload",
                  hists->stats.nr_lost_warned);
        ++printed;
    }

    if (top->sym_filter_entry) {
        perf_top__show_details(top);
        return;
    }

    if (top->evlist->enabled) {
        if (top->zero) {
            hists__delete_entries(hists);
        } else {
            hists__decay_entries(hists, top->hide_user_symbols,
                         top->hide_kernel_symbols);
        }
    }

    hists__collapse_resort(hists, NULL);
    perf_evsel__output_resort(evsel, NULL);

    hists__output_recalc_col_len(hists, top->print_entries - printed);
    putchar('\n');
    hists__fprintf(hists, false, top->print_entries - printed, win_width,
               top->min_percent, stdout, symbol_conf.use_callchain);
}

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 hists *hists = evsel__hists(top->sym_evsel);
    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(&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", perf_evsel__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->annotation_opts.min_pcnt);
    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.             \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 bool perf_top__handle_keypress(struct perf_top *top, int c)
{
    bool ret = true;

    if (!perf_top__key_mapped(top, c)) {
        struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
        struct termios save;

        perf_top__print_mapped_keys(top);
        fprintf(stdout, "\nEnter selection, or unmapped key to continue: ");
        fflush(stdout);

        set_term_quiet_input(&save);

        poll(&stdin_poll, 1, -1);
        c = getc(stdin);

        tcsetattr(0, TCSAFLUSH, &save);
        if (!perf_top__key_mapped(top, c))
            return ret;
    }

    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) {
                perf_top__resize(top);
                signal(SIGWINCH, winch_sig);
            } 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, "\nAvailable events:");

                evlist__for_each_entry(top->evlist, top->sym_evsel)
                    fprintf(stderr, "\n\t%d %s", top->sym_evsel->idx, perf_evsel__name(top->sym_evsel));

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

                if (counter >= top->evlist->nr_entries) {
                    top->sym_evsel = perf_evlist__first(top->evlist);
                    fprintf(stderr, "Sorry, no such event, using %s.\n", perf_evsel__name(top->sym_evsel));
                    sleep(1);
                    break;
                }
                evlist__for_each_entry(top->evlist, top->sym_evsel)
                    if (top->sym_evsel->idx == counter)
                        break;
            } else
                top->sym_evsel = perf_evlist__first(top->evlist);
            break;
        case 'f':
            prompt_integer(&top->count_filter, "Enter display event count filter");
            break;
        case 'F':
            prompt_percent(&top->annotation_opts.min_pcnt,
                       "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);
            ret = false;
            break;
        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;
    }

    return ret;
}

static void perf_top__sort_new_samples(void *arg)
{
    struct perf_top *t = arg;
    struct perf_evsel *evsel = t->sym_evsel;
    struct hists *hists;

    perf_top__reset_sample_counters(t);

    if (t->evlist->selected != NULL)
        t->sym_evsel = t->evlist->selected;

    hists = evsel__hists(evsel);

    if (t->evlist->enabled) {
        if (t->zero) {
            hists__delete_entries(hists);
        } else {
            hists__decay_entries(hists, t->hide_user_symbols,
                         t->hide_kernel_symbols);
        }
    }

    hists__collapse_resort(hists, NULL);
    perf_evsel__output_resort(evsel, NULL);
}

static void *display_thread_tui(void *arg)
{
    struct perf_evsel *pos;
    struct perf_top *top = arg;
    const char *help = "For a higher level overview, try: perf top --sort comm,dso";
    struct hist_browser_timer hbt = {
        .timer      = perf_top__sort_new_samples,
        .arg        = top,
        .refresh    = top->delay_secs,
    };

    /* In order to read symbols from other namespaces perf to  needs to call
     * setns(2).  This isn't permitted if the struct_fs has multiple users.
     * unshare(2) the fs so that we may continue to setns into namespaces
     * that we're observing.
     */
    unshare(CLONE_FS);

    perf_top__sort_new_samples(top);

    /*
     * Initialize the uid_filter_str, in the future the TUI will allow
     * Zooming in/out UIDs. For now juse use whatever the user passed
     * via --uid.
     */
    evlist__for_each_entry(top->evlist, pos) {
        struct hists *hists = evsel__hists(pos);
        hists->uid_filter_str = top->record_opts.target.uid_str;
    }

    perf_evlist__tui_browse_hists(top->evlist, help, &hbt,
                      top->min_percent,
                      &top->session->header.env,
                      !top->record_opts.overwrite,
                      &top->annotation_opts);

    done = 1;
    return NULL;
}

static void display_sig(int sig __maybe_unused)
{
    done = 1;
}

static void display_setup_sig(void)
{
    signal(SIGSEGV, sighandler_dump_stack);
    signal(SIGFPE, sighandler_dump_stack);
    signal(SIGINT,  display_sig);
    signal(SIGQUIT, display_sig);
    signal(SIGTERM, display_sig);
}

static void *display_thread(void *arg)
{
    struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
    struct termios save;
    struct perf_top *top = arg;
    int delay_msecs, c;

    /* In order to read symbols from other namespaces perf to  needs to call
     * setns(2).  This isn't permitted if the struct_fs has multiple users.
     * unshare(2) the fs so that we may continue to setns into namespaces
     * that we're observing.
     */
    unshare(CLONE_FS);

    display_setup_sig();
    pthread__unblock_sigwinch();
repeat:
    delay_msecs = top->delay_secs * MSEC_PER_SEC;
    set_term_quiet_input(&save);
    /* trash return*/
    getc(stdin);

    while (!done) {
        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;
            __fallthrough;
        default:
            c = getc(stdin);
            tcsetattr(0, TCSAFLUSH, &save);

            if (perf_top__handle_keypress(top, c))
                goto repeat;
            done = 1;
        }
    }

    tcsetattr(0, TCSAFLUSH, &save);
    return NULL;
}

static int hist_iter__top_callback(struct hist_entry_iter *iter,
                   struct addr_location *al, bool single,
                   void *arg)
{
    struct perf_top *top = arg;
    struct hist_entry *he = iter->he;
    struct perf_evsel *evsel = iter->evsel;

    if (perf_hpp_list.sym && single)
        perf_top__record_precise_ip(top, he, iter->sample, evsel, al->addr);

    hist__account_cycles(iter->sample->branch_stack, al, iter->sample,
             !(top->record_opts.branch_stack & PERF_SAMPLE_BRANCH_ANY));
    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 addr_location al;
    int err;

    if (!machine && perf_guest) {
        static struct intlist *seen;

        if (!seen)
            seen = intlist__new(NULL);

        if (!intlist__has_entry(seen, sample->pid)) {
            pr_err("Can't find guest [%d]'s kernel information\n",
                sample->pid);
            intlist__add(seen, sample->pid);
        }
        return;
    }

    if (!machine) {
        pr_err("%u unprocessable samples recorded.\r",
               top->session->evlist->stats.nr_unprocessable_samples++);
        return;
    }

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

    if (machine__resolve(machine, &al, sample) < 0)
        return;

    if (!machine->kptr_restrict_warned &&
        symbol_conf.kptr_restrict &&
        al.cpumode == PERF_RECORD_MISC_KERNEL) {
        if (!perf_evlist__exclude_kernel(top->session->evlist)) {
            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",
              al.map && map__has_symbols(al.map) ?
              " modules" : "");
            if (use_browser <= 0)
                sleep(5);
        }
        machine->kptr_restrict_warned = true;
    }

    if (al.sym == NULL && al.map != 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 (!machine->kptr_restrict_warned && !top->vmlinux_warned &&
            __map__is_kernel(al.map) && map__has_symbols(al.map)) {
            if (symbol_conf.vmlinux_name) {
                char serr[256];
                dso__strerror_load(al.map->dso, serr, sizeof(serr));
                ui__warning("The %s file can't be used: %s\n%s",
                        symbol_conf.vmlinux_name, serr, 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->idle) {
        struct hists *hists = evsel__hists(evsel);
        struct hist_entry_iter iter = {
            .evsel      = evsel,
            .sample     = sample,
            .add_entry_cb   = hist_iter__top_callback,
        };

        if (symbol_conf.cumulate_callchain)
            iter.ops = &hist_iter_cumulative;
        else
            iter.ops = &hist_iter_normal;

        pthread_mutex_lock(&hists->lock);

        err = hist_entry_iter__add(&iter, &al, top->max_stack, top);
        if (err < 0)
            pr_err("Problem incrementing symbol period, skipping event\n");

        pthread_mutex_unlock(&hists->lock);
    }

    addr_location__put(&al);
}

static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
{
    struct record_opts *opts = &top->record_opts;
    struct perf_evlist *evlist = top->evlist;
    struct perf_sample sample;
    struct perf_evsel *evsel;
    struct perf_mmap *md;
    struct perf_session *session = top->session;
    union perf_event *event;
    struct machine *machine;
    int ret;

    md = opts->overwrite ? &evlist->overwrite_mmap[idx] : &evlist->mmap[idx];
    if (perf_mmap__read_init(md) < 0)
        return;

    while ((event = perf_mmap__read_event(md)) != NULL) {
        ret = perf_evlist__parse_sample(evlist, event, &sample);
        if (ret) {
            pr_err("Can't parse sample, err = %d\n", ret);
            goto next_event;
        }

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

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

        switch (sample.cpumode) {
        case PERF_RECORD_MISC_USER:
            ++top->us_samples;
            if (top->hide_user_symbols)
                goto next_event;
            machine = &session->machines.host;
            break;
        case PERF_RECORD_MISC_KERNEL:
            ++top->kernel_samples;
            if (top->hide_kernel_symbols)
                goto next_event;
            machine = &session->machines.host;
            break;
        case PERF_RECORD_MISC_GUEST_KERNEL:
            ++top->guest_kernel_samples;
            machine = perf_session__find_machine(session,
                                 sample.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.
             */
            goto next_event;
        default:
            if (event->header.type == PERF_RECORD_SAMPLE)
                goto next_event;
            machine = &session->machines.host;
            break;
        }


        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(evsel), event->header.type);
            machine__process_event(machine, event, &sample);
        } else
            ++session->evlist->stats.nr_unknown_events;
next_event:
        perf_mmap__consume(md);
    }

    perf_mmap__read_done(md);
}

static void perf_top__mmap_read(struct perf_top *top)
{
    bool overwrite = top->record_opts.overwrite;
    struct perf_evlist *evlist = top->evlist;
    unsigned long long start, end;
    int i;

    start = rdclock();
    if (overwrite)
        perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_DATA_PENDING);

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

    if (overwrite) {
        perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_EMPTY);
        perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
    }
    end = rdclock();

    if ((end - start) > (unsigned long long)top->delay_secs * NSEC_PER_SEC)
        ui__warning("Too slow to read ring buffer.\n"
                "Please try increasing the period (-c) or\n"
                "decreasing the freq (-F) or\n"
                "limiting the number of CPUs (-C)\n");
}

/*
 * Check per-event overwrite term.
 * perf top should support consistent term for all events.
 * - All events don't have per-event term
 *   E.g. "cpu/cpu-cycles/,cpu/instructions/"
 *   Nothing change, return 0.
 * - All events have same per-event term
 *   E.g. "cpu/cpu-cycles,no-overwrite/,cpu/instructions,no-overwrite/
 *   Using the per-event setting to replace the opts->overwrite if
 *   they are different, then return 0.
 * - Events have different per-event term
 *   E.g. "cpu/cpu-cycles,overwrite/,cpu/instructions,no-overwrite/"
 *   Return -1
 * - Some of the event set per-event term, but some not.
 *   E.g. "cpu/cpu-cycles/,cpu/instructions,no-overwrite/"
 *   Return -1
 */
static int perf_top__overwrite_check(struct perf_top *top)
{
    struct record_opts *opts = &top->record_opts;
    struct perf_evlist *evlist = top->evlist;
    struct perf_evsel_config_term *term;
    struct list_head *config_terms;
    struct perf_evsel *evsel;
    int set, overwrite = -1;

    evlist__for_each_entry(evlist, evsel) {
        set = -1;
        config_terms = &evsel->config_terms;
        list_for_each_entry(term, config_terms, list) {
            if (term->type == PERF_EVSEL__CONFIG_TERM_OVERWRITE)
                set = term->val.overwrite ? 1 : 0;
        }

        /* no term for current and previous event (likely) */
        if ((overwrite < 0) && (set < 0))
            continue;

        /* has term for both current and previous event, compare */
        if ((overwrite >= 0) && (set >= 0) && (overwrite != set))
            return -1;

        /* no term for current event but has term for previous one */
        if ((overwrite >= 0) && (set < 0))
            return -1;

        /* has term for current event */
        if ((overwrite < 0) && (set >= 0)) {
            /* if it's first event, set overwrite */
            if (evsel == perf_evlist__first(evlist))
                overwrite = set;
            else
                return -1;
        }
    }

    if ((overwrite >= 0) && (opts->overwrite != overwrite))
        opts->overwrite = overwrite;

    return 0;
}

static int perf_top_overwrite_fallback(struct perf_top *top,
                       struct perf_evsel *evsel)
{
    struct record_opts *opts = &top->record_opts;
    struct perf_evlist *evlist = top->evlist;
    struct perf_evsel *counter;

    if (!opts->overwrite)
        return 0;

    /* only fall back when first event fails */
    if (evsel != perf_evlist__first(evlist))
        return 0;

    evlist__for_each_entry(evlist, counter)
        counter->attr.write_backward = false;
    opts->overwrite = false;
    pr_debug2("fall back to non-overwrite mode\n");
    return 1;
}

static int perf_top__start_counters(struct perf_top *top)
{
    char msg[BUFSIZ];
    struct perf_evsel *counter;
    struct perf_evlist *evlist = top->evlist;
    struct record_opts *opts = &top->record_opts;

    if (perf_top__overwrite_check(top)) {
        ui__error("perf top only support consistent per-event "
              "overwrite setting for all events\n");
        goto out_err;
    }

    perf_evlist__config(evlist, opts, &callchain_param);

    evlist__for_each_entry(evlist, counter) {
try_again:
        if (perf_evsel__open(counter, top->evlist->cpus,
                     top->evlist->threads) < 0) {

            /*
             * Specially handle overwrite fall back.
             * Because perf top is the only tool which has
             * overwrite mode by default, support
             * both overwrite and non-overwrite mode, and
             * require consistent mode for all events.
             *
             * May move it to generic code with more tools
             * have similar attribute.
             */
            if (perf_missing_features.write_backward &&
                perf_top_overwrite_fallback(top, counter))
                goto try_again;

            if (perf_evsel__fallback(counter, errno, msg, sizeof(msg))) {
                if (verbose > 0)
                    ui__warning("%s\n", msg);
                goto try_again;
            }

            perf_evsel__open_strerror(counter, &opts->target,
                          errno, msg, sizeof(msg));
            ui__error("%s\n", msg);
            goto out_err;
        }
    }

    if (perf_evlist__mmap(evlist, opts->mmap_pages) < 0) {
        ui__error("Failed to mmap with %d (%s)\n",
                errno, str_error_r(errno, msg, sizeof(msg)));
        goto out_err;
    }

    return 0;

out_err:
    return -1;
}

static int callchain_param__setup_sample_type(struct callchain_param *callchain)
{
    if (!perf_hpp_list.sym) {
        if (callchain->enabled) {
            ui__error("Selected -g but \"sym\" not present in --sort/-s.");
            return -EINVAL;
        }
    } else if (callchain->mode != CHAIN_NONE) {
        if (callchain_register_param(callchain) < 0) {
            ui__error("Can't register callchain params.\n");
            return -EINVAL;
        }
    }

    return 0;
}

static int __cmd_top(struct perf_top *top)
{
    char msg[512];
    struct perf_evsel *pos;
    struct perf_evsel_config_term *err_term;
    struct perf_evlist *evlist = top->evlist;
    struct record_opts *opts = &top->record_opts;
    pthread_t thread;
    int ret;

    top->session = perf_session__new(NULL, false, NULL);
    if (top->session == NULL)
        return -1;

    if (!top->annotation_opts.objdump_path) {
        ret = perf_env__lookup_objdump(&top->session->header.env,
                           &top->annotation_opts.objdump_path);
        if (ret)
            goto out_delete;
    }

    ret = callchain_param__setup_sample_type(&callchain_param);
    if (ret)
        goto out_delete;

    if (perf_session__register_idle_thread(top->session) < 0)
        goto out_delete;

    if (top->nr_threads_synthesize > 1)
        perf_set_multithreaded();

    machine__synthesize_threads(&top->session->machines.host, &opts->target,
                    top->evlist->threads, false,
                    opts->proc_map_timeout,
                    top->nr_threads_synthesize);

    if (top->nr_threads_synthesize > 1)
        perf_set_singlethreaded();

    if (perf_hpp_list.socket) {
        ret = perf_env__read_cpu_topology_map(&perf_env);
        if (ret < 0)
            goto out_err_cpu_topo;
    }

    ret = perf_top__start_counters(top);
    if (ret)
        goto out_delete;

    ret = perf_evlist__apply_drv_configs(evlist, &pos, &err_term);
    if (ret) {
        pr_err("failed to set config \"%s\" on event %s with %d (%s)\n",
            err_term->val.drv_cfg, perf_evsel__name(pos), errno,
            str_error_r(errno, msg, sizeof(msg)));
        goto out_delete;
    }

    top->session->evlist = top->evlist;
    perf_session__set_id_hdr_size(top->session);

    /*
     * When perf is starting the traced process, all the events (apart from
     * group members) have enable_on_exec=1 set, so don't spoil it by
     * prematurely enabling them.
     *
     * XXX 'top' still doesn't start workloads like record, trace, but should,
     * so leave the check here.
     */
        if (!target__none(&opts->target))
                perf_evlist__enable(top->evlist);

    /* Wait for a minimal set of events before starting the snapshot */
    perf_evlist__poll(top->evlist, 100);

    perf_top__mmap_read(top);

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

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

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

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

        perf_top__mmap_read(top);

        if (opts->overwrite || (hits == top->samples))
            ret = perf_evlist__poll(top->evlist, 100);

        if (resize) {
            perf_top__resize(top);
            resize = 0;
        }
    }

    ret = 0;
out_join:
    pthread_join(thread, NULL);
out_delete:
    perf_session__delete(top->session);
    top->session = NULL;

    return ret;

out_err_cpu_topo: {
    char errbuf[BUFSIZ];
    const char *err = str_error_r(-ret, errbuf, sizeof(errbuf));

    ui__error("Could not read the CPU topology map: %s\n", err);
    goto out_delete;
}
}

static int
callchain_opt(const struct option *opt, const char *arg, int unset)
{
    symbol_conf.use_callchain = true;
    return record_callchain_opt(opt, arg, unset);
}

static int
parse_callchain_opt(const struct option *opt, const char *arg, int unset)
{
    struct callchain_param *callchain = opt->value;

    callchain->enabled = !unset;
    callchain->record_mode = CALLCHAIN_FP;

    /*
     * --no-call-graph
     */
    if (unset) {
        symbol_conf.use_callchain = false;
        callchain->record_mode = CALLCHAIN_NONE;
        return 0;
    }

    return parse_callchain_top_opt(arg);
}

static int perf_top_config(const char *var, const char *value, void *cb __maybe_unused)
{
    if (!strcmp(var, "top.call-graph")) {
        var = "call-graph.record-mode";
        return perf_default_config(var, value, cb);
    }
    if (!strcmp(var, "top.children")) {
        symbol_conf.cumulate_callchain = perf_config_bool(var, value);
        return 0;
    }

    return 0;
}

static int
parse_percent_limit(const struct option *opt, const char *arg,
            int unset __maybe_unused)
{
    struct perf_top *top = opt->value;

    top->min_percent = strtof(arg, NULL);
    return 0;
}

const char top_callchain_help[] = CALLCHAIN_RECORD_HELP CALLCHAIN_REPORT_HELP
    "\n\t\t\t\tDefault: fp,graph,0.5,caller,function";

int cmd_top(int argc, const char **argv)
{
    char errbuf[BUFSIZ];
    struct perf_top top = {
        .count_filter        = 5,
        .delay_secs      = 2,
        .record_opts = {
            .mmap_pages = UINT_MAX,
            .user_freq  = UINT_MAX,
            .user_interval  = ULLONG_MAX,
            .freq       = 4000, /* 4 KHz */
            .target     = {
                .uses_mmap   = true,
            },
            .proc_map_timeout    = 500,
            .overwrite  = 1,
        },
        .max_stack       = sysctl__max_stack(),
        .annotation_opts     = annotation__default_options,
        .nr_threads_synthesize = UINT_MAX,
    };
    struct record_opts *opts = &top.record_opts;
    struct target *target = &opts->target;
    const struct option options[] = {
    OPT_CALLBACK('e', "event", &top.evlist, "event",
             "event selector. use 'perf list' to list available events",
             parse_events_option),
    OPT_U64('c', "count", &opts->user_interval, "event period to sample"),
    OPT_STRING('p', "pid", &target->pid, "pid",
            "profile events on existing process id"),
    OPT_STRING('t', "tid", &target->tid, "tid",
            "profile events on existing thread id"),
    OPT_BOOLEAN('a', "all-cpus", &target->system_wide,
                "system-wide collection from all CPUs"),
    OPT_STRING('C', "cpu", &target->cpu_list, "cpu",
            "list of cpus to monitor"),
    OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
           "file", "vmlinux pathname"),
    OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux,
            "don't load vmlinux even if found"),
    OPT_BOOLEAN('K', "hide_kernel_symbols", &top.hide_kernel_symbols,
            "hide kernel symbols"),
    OPT_CALLBACK('m', "mmap-pages", &opts->mmap_pages, "pages",
             "number of mmap data pages",
             perf_evlist__parse_mmap_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(0, "group", &opts->group,
                "put the counters into a counter group"),
    OPT_BOOLEAN('i', "no-inherit", &opts->no_inherit,
            "child tasks do not 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_CALLBACK('F', "freq", &top.record_opts, "freq or 'max'",
             "profile at this frequency",
              record__parse_freq),
    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, cpu, srcline, ..."
           " Please refer the man page for the complete list."),
    OPT_STRING(0, "fields", &field_order, "key[,keys...]",
           "output field(s): overhead, period, sample plus all of sort keys"),
    OPT_BOOLEAN('n', "show-nr-samples", &symbol_conf.show_nr_samples,
            "Show a column with the number of samples"),
    OPT_CALLBACK_NOOPT('g', NULL, &callchain_param,
               NULL, "enables call-graph recording and display",
               &callchain_opt),
    OPT_CALLBACK(0, "call-graph", &callchain_param,
             "record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]",
             top_callchain_help, &parse_callchain_opt),
    OPT_BOOLEAN(0, "children", &symbol_conf.cumulate_callchain,
            "Accumulate callchains of children and show total overhead as well"),
    OPT_INTEGER(0, "max-stack", &top.max_stack,
            "Set the maximum stack depth when parsing the callchain. "
            "Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)),
    OPT_CALLBACK(0, "ignore-callees", NULL, "regex",
           "ignore callees of these functions in call graphs",
           report_parse_ignore_callees_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", &top.annotation_opts.annotate_src,
            "Interleave source code with assembly code (default)"),
    OPT_BOOLEAN(0, "asm-raw", &top.annotation_opts.show_asm_raw,
            "Display raw encoding of assembly instructions (default)"),
    OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
            "Enable kernel symbol demangling"),
    OPT_STRING(0, "objdump", &top.annotation_opts.objdump_path, "path",
            "objdump binary to use for disassembly and annotations"),
    OPT_STRING('M', "disassembler-style", &top.annotation_opts.disassembler_style, "disassembler style",
           "Specify disassembler style (e.g. -M intel for intel syntax)"),
    OPT_STRING('u', "uid", &target->uid_str, "user", "user to profile"),
    OPT_CALLBACK(0, "percent-limit", &top, "percent",
             "Don't show entries under that percent", parse_percent_limit),
    OPT_CALLBACK(0, "percentage", NULL, "relative|absolute",
             "How to display percentage of filtered entries", parse_filter_percentage),
    OPT_STRING('w', "column-widths", &symbol_conf.col_width_list_str,
           "width[,width...]",
           "don't try to adjust column width, use these fixed values"),
    OPT_UINTEGER(0, "proc-map-timeout", &opts->proc_map_timeout,
            "per thread proc mmap processing timeout in ms"),
    OPT_CALLBACK_NOOPT('b', "branch-any", &opts->branch_stack,
             "branch any", "sample any taken branches",
             parse_branch_stack),
    OPT_CALLBACK('j', "branch-filter", &opts->branch_stack,
             "branch filter mask", "branch stack filter modes",
             parse_branch_stack),
    OPT_BOOLEAN(0, "raw-trace", &symbol_conf.raw_trace,
            "Show raw trace event output (do not use print fmt or plugins)"),
    OPT_BOOLEAN(0, "hierarchy", &symbol_conf.report_hierarchy,
            "Show entries in a hierarchy"),
    OPT_BOOLEAN(0, "force", &symbol_conf.force, "don't complain, do it"),
    OPT_UINTEGER(0, "num-thread-synthesize", &top.nr_threads_synthesize,
            "number of thread to run event synthesize"),
    OPT_END()
    };
    const char * const top_usage[] = {
        "perf top [<options>]",
        NULL
    };
    int status = hists__init();

    if (status < 0)
        return status;

    top.annotation_opts.min_pcnt = 5;
    top.annotation_opts.context  = 4;

    top.evlist = perf_evlist__new();
    if (top.evlist == NULL)
        return -ENOMEM;

    status = perf_config(perf_top_config, &top);
    if (status)
        return status;

    argc = parse_options(argc, argv, options, top_usage, 0);
    if (argc)
        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");
        goto out_delete_evlist;
    }

    if (symbol_conf.report_hierarchy) {
        /* disable incompatible options */
        symbol_conf.event_group = false;
        symbol_conf.cumulate_callchain = false;

        if (field_order) {
            pr_err("Error: --hierarchy and --fields options cannot be used together\n");
            parse_options_usage(top_usage, options, "fields", 0);
            parse_options_usage(NULL, options, "hierarchy", 0);
            goto out_delete_evlist;
        }
    }

    sort__mode = SORT_MODE__TOP;
    /* display thread wants entries to be collapsed in a different tree */
    perf_hpp_list.need_collapse = 1;

    if (top.use_stdio)
        use_browser = 0;
    else if (top.use_tui)
        use_browser = 1;

    setup_browser(false);

    if (setup_sorting(top.evlist) < 0) {
        if (sort_order)
            parse_options_usage(top_usage, options, "s", 1);
        if (field_order)
            parse_options_usage(sort_order ? NULL : top_usage,
                        options, "fields", 0);
        goto out_delete_evlist;
    }

    status = target__validate(target);
    if (status) {
        target__strerror(target, status, errbuf, BUFSIZ);
        ui__warning("%s\n", errbuf);
    }

    status = target__parse_uid(target);
    if (status) {
        int saved_errno = errno;

        target__strerror(target, status, errbuf, BUFSIZ);
        ui__error("%s\n", errbuf);

        status = -saved_errno;
        goto out_delete_evlist;
    }

    if (target__none(target))
        target->system_wide = true;

    if (perf_evlist__create_maps(top.evlist, target) < 0) {
        ui__error("Couldn't create thread/CPU maps: %s\n",
              errno == ENOENT ? "No such process" : str_error_r(errno, errbuf, sizeof(errbuf)));
        goto out_delete_evlist;
    }

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

    if (record_opts__config(opts)) {
        status = -EINVAL;
        goto out_delete_evlist;
    }

    top.sym_evsel = perf_evlist__first(top.evlist);

    if (!callchain_param.enabled) {
        symbol_conf.cumulate_callchain = false;
        perf_hpp__cancel_cumulate();
    }

    if (symbol_conf.cumulate_callchain && !callchain_param.order_set)
        callchain_param.order = ORDER_CALLER;

    status = symbol__annotation_init();
    if (status < 0)
        goto out_delete_evlist;

    annotation_config__init();

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

    sort__setup_elide(stdout);

    get_term_dimensions(&top.winsize);
    if (top.print_entries == 0) {
        perf_top__update_print_entries(&top);
        signal(SIGWINCH, winch_sig);
    }

    status = __cmd_top(&top);

out_delete_evlist:
    perf_evlist__delete(top.evlist);

    return status;
}