Merge branches 'bugzilla-14446', 'bugzilla-14753' and 'bugzilla-14824' into release

[mirror_ubuntu-artful-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>
 *
 * 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/color.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/util.h"
#include <linux/rbtree.h>
#include "util/parse-options.h"
#include "util/parse-events.h"

#include "util/debug.h"

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

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

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

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

#include <linux/unistd.h>
#include <linux/types.h>

static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];

static int                      system_wide                     =      0;

static int                      default_interval                =      0;

static int                      count_filter                    =      5;
static int                      print_entries;

static int                      target_pid                      =     -1;
static int                      inherit                         =      0;
static int                      profile_cpu                     =     -1;
static int                      nr_cpus                         =      0;
static unsigned int             realtime_prio                   =      0;
static int                      group                           =      0;
static unsigned int             page_size;
static unsigned int             mmap_pages                      =     16;
static int                      freq                            =   1000; /* 1 KHz */

static int                      delay_secs                      =      2;
static int                      zero                            =      0;
static int                      dump_symtab                     =      0;

static bool                     hide_kernel_symbols             =  false;
static bool                     hide_user_symbols               =  false;
static struct winsize           winsize;

/*
 * Source
 */

struct source_line {
        u64                     eip;
        unsigned long           count[MAX_COUNTERS];
        char                    *line;
        struct source_line      *next;
};

static char                     *sym_filter                     =   NULL;
struct sym_entry                *sym_filter_entry               =   NULL;
static int                      sym_pcnt_filter                 =      5;
static int                      sym_counter                     =      0;
static int                      display_weighted                =     -1;

/*
 * Symbols
 */

struct sym_entry_source {
        struct source_line      *source;
        struct source_line      *lines;
        struct source_line      **lines_tail;
        pthread_mutex_t         lock;
};

struct sym_entry {
        struct rb_node          rb_node;
        struct list_head        node;
        unsigned long           snap_count;
        double                  weight;
        int                     skip;
        u16                     name_len;
        u8                      origin;
        struct map              *map;
        struct sym_entry_source *src;
        unsigned long           count[0];
};

/*
 * Source functions
 */

static inline struct symbol *sym_entry__symbol(struct sym_entry *self)
{
       return ((void *)self) + symbol_conf.priv_size;
}

static void get_term_dimensions(struct winsize *ws)
{
        char *s = getenv("LINES");

        if (s != NULL) {
                ws->ws_row = atoi(s);
                s = getenv("COLUMNS");
                if (s != NULL) {
                        ws->ws_col = atoi(s);
                        if (ws->ws_row && ws->ws_col)
                                return;
                }
        }
#ifdef TIOCGWINSZ
        if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
            ws->ws_row && ws->ws_col)
                return;
#endif
        ws->ws_row = 25;
        ws->ws_col = 80;
}

static void update_print_entries(struct winsize *ws)
{
        print_entries = ws->ws_row;

        if (print_entries > 9)
                print_entries -= 9;
}

static void sig_winch_handler(int sig __used)
{
        get_term_dimensions(&winsize);
        update_print_entries(&winsize);
}

static void parse_source(struct sym_entry *syme)
{
        struct symbol *sym;
        struct sym_entry_source *source;
        struct map *map;
        FILE *file;
        char command[PATH_MAX*2];
        const char *path;
        u64 len;

        if (!syme)
                return;

        if (syme->src == NULL) {
                syme->src = zalloc(sizeof(*source));
                if (syme->src == NULL)
                        return;
                pthread_mutex_init(&syme->src->lock, NULL);
        }

        source = syme->src;

        if (source->lines) {
                pthread_mutex_lock(&source->lock);
                goto out_assign;
        }

        sym = sym_entry__symbol(syme);
        map = syme->map;
        path = map->dso->long_name;

        len = sym->end - sym->start;

        sprintf(command,
                "objdump --start-address=0x%016Lx "
                         "--stop-address=0x%016Lx -dS %s",
                map->unmap_ip(map, sym->start),
                map->unmap_ip(map, sym->end), path);

        file = popen(command, "r");
        if (!file)
                return;

        pthread_mutex_lock(&source->lock);
        source->lines_tail = &source->lines;
        while (!feof(file)) {
                struct source_line *src;
                size_t dummy = 0;
                char *c;

                src = malloc(sizeof(struct source_line));
                assert(src != NULL);
                memset(src, 0, sizeof(struct source_line));

                if (getline(&src->line, &dummy, file) < 0)
                        break;
                if (!src->line)
                        break;

                c = strchr(src->line, '\n');
                if (c)
                        *c = 0;

                src->next = NULL;
                *source->lines_tail = src;
                source->lines_tail = &src->next;

                if (strlen(src->line)>8 && src->line[8] == ':') {
                        src->eip = strtoull(src->line, NULL, 16);
                        src->eip = map->unmap_ip(map, src->eip);
                }
                if (strlen(src->line)>8 && src->line[16] == ':') {
                        src->eip = strtoull(src->line, NULL, 16);
                        src->eip = map->unmap_ip(map, src->eip);
                }
        }
        pclose(file);
out_assign:
        sym_filter_entry = syme;
        pthread_mutex_unlock(&source->lock);
}

static void __zero_source_counters(struct sym_entry *syme)
{
        int i;
        struct source_line *line;

        line = syme->src->lines;
        while (line) {
                for (i = 0; i < nr_counters; i++)
                        line->count[i] = 0;
                line = line->next;
        }
}

static void record_precise_ip(struct sym_entry *syme, int counter, u64 ip)
{
        struct source_line *line;

        if (syme != sym_filter_entry)
                return;

        if (pthread_mutex_trylock(&syme->src->lock))
                return;

        if (syme->src == NULL || syme->src->source == NULL)
                goto out_unlock;

        for (line = syme->src->lines; line; line = line->next) {
                if (line->eip == ip) {
                        line->count[counter]++;
                        break;
                }
                if (line->eip > ip)
                        break;
        }
out_unlock:
        pthread_mutex_unlock(&syme->src->lock);
}

static void lookup_sym_source(struct sym_entry *syme)
{
        struct symbol *symbol = sym_entry__symbol(syme);
        struct source_line *line;
        char pattern[PATH_MAX];

        sprintf(pattern, "<%s>:", symbol->name);

        pthread_mutex_lock(&syme->src->lock);
        for (line = syme->src->lines; line; line = line->next) {
                if (strstr(line->line, pattern)) {
                        syme->src->source = line;
                        break;
                }
        }
        pthread_mutex_unlock(&syme->src->lock);
}

static void show_lines(struct source_line *queue, int count, int total)
{
        int i;
        struct source_line *line;

        line = queue;
        for (i = 0; i < count; i++) {
                float pcnt = 100.0*(float)line->count[sym_counter]/(float)total;

                printf("%8li %4.1f%%\t%s\n", line->count[sym_counter], pcnt, line->line);
                line = line->next;
        }
}

#define TRACE_COUNT     3

static void show_details(struct sym_entry *syme)
{
        struct symbol *symbol;
        struct source_line *line;
        struct source_line *line_queue = NULL;
        int displayed = 0;
        int line_queue_count = 0, total = 0, more = 0;

        if (!syme)
                return;

        if (!syme->src->source)
                lookup_sym_source(syme);

        if (!syme->src->source)
                return;

        symbol = sym_entry__symbol(syme);
        printf("Showing %s for %s\n", event_name(sym_counter), symbol->name);
        printf("  Events  Pcnt (>=%d%%)\n", sym_pcnt_filter);

        pthread_mutex_lock(&syme->src->lock);
        line = syme->src->source;
        while (line) {
                total += line->count[sym_counter];
                line = line->next;
        }

        line = syme->src->source;
        while (line) {
                float pcnt = 0.0;

                if (!line_queue_count)
                        line_queue = line;
                line_queue_count++;

                if (line->count[sym_counter])
                        pcnt = 100.0 * line->count[sym_counter] / (float)total;
                if (pcnt >= (float)sym_pcnt_filter) {
                        if (displayed <= print_entries)
                                show_lines(line_queue, line_queue_count, total);
                        else more++;
                        displayed += line_queue_count;
                        line_queue_count = 0;
                        line_queue = NULL;
                } else if (line_queue_count > TRACE_COUNT) {
                        line_queue = line_queue->next;
                        line_queue_count--;
                }

                line->count[sym_counter] = zero ? 0 : line->count[sym_counter] * 7 / 8;
                line = line->next;
        }
        pthread_mutex_unlock(&syme->src->lock);
        if (more)
                printf("%d lines not displayed, maybe increase display entries [e]\n", more);
}

/*
 * Symbols will be added here in event__process_sample and will get out
 * after decayed.
 */
static LIST_HEAD(active_symbols);
static pthread_mutex_t active_symbols_lock = PTHREAD_MUTEX_INITIALIZER;

/*
 * Ordering weight: count-1 * count-2 * ... / count-n
 */
static double sym_weight(const struct sym_entry *sym)
{
        double weight = sym->snap_count;
        int counter;

        if (!display_weighted)
                return weight;

        for (counter = 1; counter < nr_counters-1; counter++)
                weight *= sym->count[counter];

        weight /= (sym->count[counter] + 1);

        return weight;
}

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

static void __list_insert_active_sym(struct sym_entry *syme)
{
        list_add(&syme->node, &active_symbols);
}

static void list_remove_active_sym(struct sym_entry *syme)
{
        pthread_mutex_lock(&active_symbols_lock);
        list_del_init(&syme->node);
        pthread_mutex_unlock(&active_symbols_lock);
}

static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
{
        struct rb_node **p = &tree->rb_node;
        struct rb_node *parent = NULL;
        struct sym_entry *iter;

        while (*p != NULL) {
                parent = *p;
                iter = rb_entry(parent, struct sym_entry, rb_node);

                if (se->weight > iter->weight)
                        p = &(*p)->rb_left;
                else
                        p = &(*p)->rb_right;
        }

        rb_link_node(&se->rb_node, parent, p);
        rb_insert_color(&se->rb_node, tree);
}

static void print_sym_table(void)
{
        int printed = 0, j;
        int counter, snap = !display_weighted ? sym_counter : 0;
        float samples_per_sec = samples/delay_secs;
        float ksamples_per_sec = (samples-userspace_samples)/delay_secs;
        float sum_ksamples = 0.0;
        struct sym_entry *syme, *n;
        struct rb_root tmp = RB_ROOT;
        struct rb_node *nd;
        int sym_width = 0, dso_width = 0, max_dso_width;
        const int win_width = winsize.ws_col - 1;

        samples = userspace_samples = 0;

        /* Sort the active symbols */
        pthread_mutex_lock(&active_symbols_lock);
        syme = list_entry(active_symbols.next, struct sym_entry, node);
        pthread_mutex_unlock(&active_symbols_lock);

        list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
                syme->snap_count = syme->count[snap];
                if (syme->snap_count != 0) {

                        if ((hide_user_symbols &&
                             syme->origin == PERF_RECORD_MISC_USER) ||
                            (hide_kernel_symbols &&
                             syme->origin == PERF_RECORD_MISC_KERNEL)) {
                                list_remove_active_sym(syme);
                                continue;
                        }
                        syme->weight = sym_weight(syme);
                        rb_insert_active_sym(&tmp, syme);
                        sum_ksamples += syme->snap_count;

                        for (j = 0; j < nr_counters; j++)
                                syme->count[j] = zero ? 0 : syme->count[j] * 7 / 8;
                } else
                        list_remove_active_sym(syme);
        }

        puts(CONSOLE_CLEAR);

        printf("%-*.*s\n", win_width, win_width, graph_dotted_line);
        printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%% [",
                samples_per_sec,
                100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)));

        if (nr_counters == 1 || !display_weighted) {
                printf("%Ld", (u64)attrs[0].sample_period);
                if (freq)
                        printf("Hz ");
                else
                        printf(" ");
        }

        if (!display_weighted)
                printf("%s", event_name(sym_counter));
        else for (counter = 0; counter < nr_counters; counter++) {
                if (counter)
                        printf("/");

                printf("%s", event_name(counter));
        }

        printf( "], ");

        if (target_pid != -1)
                printf(" (target_pid: %d", target_pid);
        else
                printf(" (all");

        if (profile_cpu != -1)
                printf(", cpu: %d)\n", profile_cpu);
        else {
                if (target_pid != -1)
                        printf(")\n");
                else
                        printf(", %d CPUs)\n", nr_cpus);
        }

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

        if (sym_filter_entry) {
                show_details(sym_filter_entry);
                return;
        }

        /*
         * Find the longest symbol name that will be displayed
         */
        for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) {
                syme = rb_entry(nd, struct sym_entry, rb_node);
                if (++printed > print_entries ||
                    (int)syme->snap_count < count_filter)
                        continue;

                if (syme->map->dso->long_name_len > dso_width)
                        dso_width = syme->map->dso->long_name_len;

                if (syme->name_len > sym_width)
                        sym_width = syme->name_len;
        }

        printed = 0;

        max_dso_width = winsize.ws_col - sym_width - 29;
        if (dso_width > max_dso_width)
                dso_width = max_dso_width;
        putchar('\n');
        if (nr_counters == 1)
                printf("             samples  pcnt");
        else
                printf("   weight    samples  pcnt");

        if (verbose)
                printf("         RIP       ");
        printf(" %-*.*s DSO\n", sym_width, sym_width, "function");
        printf("   %s    _______ _____",
               nr_counters == 1 ? "      " : "______");
        if (verbose)
                printf(" ________________");
        printf(" %-*.*s", sym_width, sym_width, graph_line);
        printf(" %-*.*s", dso_width, dso_width, graph_line);
        puts("\n");

        for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) {
                struct symbol *sym;
                double pcnt;

                syme = rb_entry(nd, struct sym_entry, rb_node);
                sym = sym_entry__symbol(syme);

                if (++printed > print_entries || (int)syme->snap_count < count_filter)
                        continue;

                pcnt = 100.0 - (100.0 * ((sum_ksamples - syme->snap_count) /
                                         sum_ksamples));

                if (nr_counters == 1 || !display_weighted)
                        printf("%20.2f ", syme->weight);
                else
                        printf("%9.1f %10ld ", syme->weight, syme->snap_count);

                percent_color_fprintf(stdout, "%4.1f%%", pcnt);
                if (verbose)
                        printf(" %016llx", sym->start);
                printf(" %-*.*s", sym_width, sym_width, sym->name);
                printf(" %-*.*s\n", dso_width, dso_width,
                       dso_width >= syme->map->dso->long_name_len ?
                                        syme->map->dso->long_name :
                                        syme->map->dso->short_name);
        }
}

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 prompt_symbol(struct sym_entry **target, const char *msg)
{
        char *buf = malloc(0), *p;
        struct sym_entry *syme = *target, *n, *found = NULL;
        size_t dummy = 0;

        /* zero counters of active symbol */
        if (syme) {
                pthread_mutex_lock(&syme->src->lock);
                __zero_source_counters(syme);
                *target = NULL;
                pthread_mutex_unlock(&syme->src->lock);
        }

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

        p = strchr(buf, '\n');
        if (p)
                *p = 0;

        pthread_mutex_lock(&active_symbols_lock);
        syme = list_entry(active_symbols.next, struct sym_entry, node);
        pthread_mutex_unlock(&active_symbols_lock);

        list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
                struct symbol *sym = sym_entry__symbol(syme);

                if (!strcmp(buf, sym->name)) {
                        found = syme;
                        break;
                }
        }

        if (!found) {
                fprintf(stderr, "Sorry, %s is not active.\n", sym_filter);
                sleep(1);
                return;
        } else
                parse_source(found);

out_free:
        free(buf);
}

static void print_mapped_keys(void)
{
        char *name = NULL;

        if (sym_filter_entry) {
                struct symbol *sym = sym_entry__symbol(sym_filter_entry);
                name = sym->name;
        }

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

        if (nr_counters > 1)
                fprintf(stdout, "\t[E]     active event counter.              \t(%s)\n", event_name(sym_counter));

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

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

        if (nr_counters > 1)
                fprintf(stdout, "\t[w]     toggle display weighted/count[E]r. \t(%d)\n", display_weighted ? 1 : 0);

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

static int key_mapped(int c)
{
        switch (c) {
                case 'd':
                case 'e':
                case 'f':
                case 'z':
                case 'q':
                case 'Q':
                case 'K':
                case 'U':
                        return 1;
                case 'E':
                case 'w':
                        return nr_counters > 1 ? 1 : 0;
                case 'F':
                case 's':
                case 'S':
                        return symbol_conf.vmlinux_name ? 1 : 0;
                default:
                        break;
        }

        return 0;
}

static void handle_keypress(int c)
{
        if (!key_mapped(c)) {
                struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
                struct termios tc, save;

                print_mapped_keys();
                fprintf(stdout, "\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 (!key_mapped(c))
                        return;
        }

        switch (c) {
                case 'd':
                        prompt_integer(&delay_secs, "Enter display delay");
                        if (delay_secs < 1)
                                delay_secs = 1;
                        break;
                case 'e':
                        prompt_integer(&print_entries, "Enter display entries (lines)");
                        if (print_entries == 0) {
                                sig_winch_handler(SIGWINCH);
                                signal(SIGWINCH, sig_winch_handler);
                        } else
                                signal(SIGWINCH, SIG_DFL);
                        break;
                case 'E':
                        if (nr_counters > 1) {
                                int i;

                                fprintf(stderr, "\nAvailable events:");
                                for (i = 0; i < nr_counters; i++)
                                        fprintf(stderr, "\n\t%d %s", i, event_name(i));

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

                                if (sym_counter >= nr_counters) {
                                        fprintf(stderr, "Sorry, no such event, using %s.\n", event_name(0));
                                        sym_counter = 0;
                                        sleep(1);
                                }
                        } else sym_counter = 0;
                        break;
                case 'f':
                        prompt_integer(&count_filter, "Enter display event count filter");
                        break;
                case 'F':
                        prompt_percent(&sym_pcnt_filter, "Enter details display event filter (percent)");
                        break;
                case 'K':
                        hide_kernel_symbols = !hide_kernel_symbols;
                        break;
                case 'q':
                case 'Q':
                        printf("exiting.\n");
                        if (dump_symtab)
                                dsos__fprintf(stderr);
                        exit(0);
                case 's':
                        prompt_symbol(&sym_filter_entry, "Enter details symbol");
                        break;
                case 'S':
                        if (!sym_filter_entry)
                                break;
                        else {
                                struct sym_entry *syme = sym_filter_entry;

                                pthread_mutex_lock(&syme->src->lock);
                                sym_filter_entry = NULL;
                                __zero_source_counters(syme);
                                pthread_mutex_unlock(&syme->src->lock);
                        }
                        break;
                case 'U':
                        hide_user_symbols = !hide_user_symbols;
                        break;
                case 'w':
                        display_weighted = ~display_weighted;
                        break;
                case 'z':
                        zero = ~zero;
                        break;
                default:
                        break;
        }
}

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

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

repeat:
        delay_msecs = delay_secs * 1000;
        tcsetattr(0, TCSANOW, &tc);
        /* trash return*/
        getc(stdin);

        do {
                print_sym_table();
        } while (!poll(&stdin_poll, 1, delay_msecs) == 1);

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

        handle_keypress(c);
        goto repeat;

        return NULL;
}

/* Tag samples to be skipped. */
static const char *skip_symbols[] = {
        "default_idle",
        "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, struct symbol *sym)
{
        struct sym_entry *syme;
        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;

        syme = symbol__priv(sym);
        syme->map = map;
        syme->src = NULL;
        if (!sym_filter_entry && sym_filter && !strcmp(name, sym_filter))
                sym_filter_entry = syme;

        for (i = 0; skip_symbols[i]; i++) {
                if (!strcmp(skip_symbols[i], name)) {
                        syme->skip = 1;
                        break;
                }
        }

        if (!syme->skip)
                syme->name_len = strlen(sym->name);

        return 0;
}

static void event__process_sample(const event_t *self,
                                 struct perf_session *session, int counter)
{
        u64 ip = self->ip.ip;
        struct sym_entry *syme;
        struct addr_location al;
        u8 origin = self->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

        switch (origin) {
        case PERF_RECORD_MISC_USER:
                if (hide_user_symbols)
                        return;
                break;
        case PERF_RECORD_MISC_KERNEL:
                if (hide_kernel_symbols)
                        return;
                break;
        default:
                return;
        }

        if (event__preprocess_sample(self, session, &al, symbol_filter) < 0 ||
            al.sym == NULL || al.filtered)
                return;

        syme = symbol__priv(al.sym);
        if (!syme->skip) {
                syme->count[counter]++;
                syme->origin = origin;
                record_precise_ip(syme, counter, ip);
                pthread_mutex_lock(&active_symbols_lock);
                if (list_empty(&syme->node) || !syme->node.next)
                        __list_insert_active_sym(syme);
                pthread_mutex_unlock(&active_symbols_lock);
                if (origin == PERF_RECORD_MISC_USER)
                        ++userspace_samples;
                ++samples;
        }
}

static int event__process(event_t *event, struct perf_session *session)
{
        switch (event->header.type) {
        case PERF_RECORD_COMM:
                event__process_comm(event, session);
                break;
        case PERF_RECORD_MMAP:
                event__process_mmap(event, session);
                break;
        default:
                break;
        }

        return 0;
}

struct mmap_data {
        int                     counter;
        void                    *base;
        int                     mask;
        unsigned int            prev;
};

static unsigned int mmap_read_head(struct mmap_data *md)
{
        struct perf_event_mmap_page *pc = md->base;
        int head;

        head = pc->data_head;
        rmb();

        return head;
}

static void perf_session__mmap_read_counter(struct perf_session *self,
                                            struct mmap_data *md)
{
        unsigned int head = mmap_read_head(md);
        unsigned int old = md->prev;
        unsigned char *data = md->base + page_size;
        int diff;

        /*
         * If we're further behind than half the buffer, there's a chance
         * the writer will bite our tail and mess up the samples under us.
         *
         * If we somehow ended up ahead of the head, we got messed up.
         *
         * In either case, truncate and restart at head.
         */
        diff = head - old;
        if (diff > md->mask / 2 || diff < 0) {
                fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");

                /*
                 * head points to a known good entry, start there.
                 */
                old = head;
        }

        for (; old != head;) {
                event_t *event = (event_t *)&data[old & md->mask];

                event_t event_copy;

                size_t size = event->header.size;

                /*
                 * Event straddles the mmap boundary -- header should always
                 * be inside due to u64 alignment of output.
                 */
                if ((old & md->mask) + size != ((old + size) & md->mask)) {
                        unsigned int offset = old;
                        unsigned int len = min(sizeof(*event), size), cpy;
                        void *dst = &event_copy;

                        do {
                                cpy = min(md->mask + 1 - (offset & md->mask), len);
                                memcpy(dst, &data[offset & md->mask], cpy);
                                offset += cpy;
                                dst += cpy;
                                len -= cpy;
                        } while (len);

                        event = &event_copy;
                }

                if (event->header.type == PERF_RECORD_SAMPLE)
                        event__process_sample(event, self, md->counter);
                else
                        event__process(event, self);
                old += size;
        }

        md->prev = old;
}

static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];

static void perf_session__mmap_read(struct perf_session *self)
{
        int i, counter;

        for (i = 0; i < nr_cpus; i++) {
                for (counter = 0; counter < nr_counters; counter++)
                        perf_session__mmap_read_counter(self, &mmap_array[i][counter]);
        }
}

int nr_poll;
int group_fd;

static void start_counter(int i, int counter)
{
        struct perf_event_attr *attr;
        int cpu;

        cpu = profile_cpu;
        if (target_pid == -1 && profile_cpu == -1)
                cpu = i;

        attr = attrs + counter;

        attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;

        if (freq) {
                attr->sample_type       |= PERF_SAMPLE_PERIOD;
                attr->freq              = 1;
                attr->sample_freq       = freq;
        }

        attr->inherit           = (cpu < 0) && inherit;
        attr->mmap              = 1;

try_again:
        fd[i][counter] = sys_perf_event_open(attr, target_pid, cpu, group_fd, 0);

        if (fd[i][counter] < 0) {
                int err = errno;

                if (err == EPERM || err == EACCES)
                        die("No permission - are you root?\n");
                /*
                 * 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)
                                warning(" ... trying to fall back to cpu-clock-ticks\n");

                        attr->type = PERF_TYPE_SOFTWARE;
                        attr->config = PERF_COUNT_SW_CPU_CLOCK;
                        goto try_again;
                }
                printf("\n");
                error("perfcounter syscall returned with %d (%s)\n",
                        fd[i][counter], strerror(err));
                die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
                exit(-1);
        }
        assert(fd[i][counter] >= 0);
        fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);

        /*
         * First counter acts as the group leader:
         */
        if (group && group_fd == -1)
                group_fd = fd[i][counter];

        event_array[nr_poll].fd = fd[i][counter];
        event_array[nr_poll].events = POLLIN;
        nr_poll++;

        mmap_array[i][counter].counter = counter;
        mmap_array[i][counter].prev = 0;
        mmap_array[i][counter].mask = mmap_pages*page_size - 1;
        mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
                        PROT_READ, MAP_SHARED, fd[i][counter], 0);
        if (mmap_array[i][counter].base == MAP_FAILED)
                die("failed to mmap with %d (%s)\n", errno, strerror(errno));
}

static int __cmd_top(void)
{
        pthread_t thread;
        int i, counter;
        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.
         */
        struct perf_session *session = perf_session__new(NULL, O_WRONLY, false);
        if (session == NULL)
                return -ENOMEM;

        if (target_pid != -1)
                event__synthesize_thread(target_pid, event__process, session);
        else
                event__synthesize_threads(event__process, session);

        for (i = 0; i < nr_cpus; i++) {
                group_fd = -1;
                for (counter = 0; counter < nr_counters; counter++)
                        start_counter(i, counter);
        }

        /* Wait for a minimal set of events before starting the snapshot */
        poll(event_array, nr_poll, 100);

        perf_session__mmap_read(session);

        if (pthread_create(&thread, NULL, display_thread, NULL)) {
                printf("Could not create display thread.\n");
                exit(-1);
        }

        if (realtime_prio) {
                struct sched_param param;

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

        while (1) {
                int hits = samples;

                perf_session__mmap_read(session);

                if (hits == samples)
                        ret = poll(event_array, nr_poll, 100);
        }

        return 0;
}

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

static const struct option options[] = {
        OPT_CALLBACK('e', "event", NULL, "event",
                     "event selector. use 'perf list' to list available events",
                     parse_events),
        OPT_INTEGER('c', "count", &default_interval,
                    "event period to sample"),
        OPT_INTEGER('p', "pid", &target_pid,
                    "profile events on existing pid"),
        OPT_BOOLEAN('a', "all-cpus", &system_wide,
                            "system-wide collection from all CPUs"),
        OPT_INTEGER('C', "CPU", &profile_cpu,
                    "CPU to profile on"),
        OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
                   "file", "vmlinux pathname"),
        OPT_BOOLEAN('K', "hide_kernel_symbols", &hide_kernel_symbols,
                    "hide kernel symbols"),
        OPT_INTEGER('m', "mmap-pages", &mmap_pages,
                    "number of mmap data pages"),
        OPT_INTEGER('r', "realtime", &realtime_prio,
                    "collect data with this RT SCHED_FIFO priority"),
        OPT_INTEGER('d', "delay", &delay_secs,
                    "number of seconds to delay between refreshes"),
        OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
                            "dump the symbol table used for profiling"),
        OPT_INTEGER('f', "count-filter", &count_filter,
                    "only display functions with more events than this"),
        OPT_BOOLEAN('g', "group", &group,
                            "put the counters into a counter group"),
        OPT_BOOLEAN('i', "inherit", &inherit,
                    "child tasks inherit counters"),
        OPT_STRING('s', "sym-annotate", &sym_filter, "symbol name",
                    "symbol to annotate - requires -k option"),
        OPT_BOOLEAN('z', "zero", &zero,
                    "zero history across updates"),
        OPT_INTEGER('F', "freq", &freq,
                    "profile at this frequency"),
        OPT_INTEGER('E', "entries", &print_entries,
                    "display this many functions"),
        OPT_BOOLEAN('U', "hide_user_symbols", &hide_user_symbols,
                    "hide user symbols"),
        OPT_BOOLEAN('v', "verbose", &verbose,
                    "be more verbose (show counter open errors, etc)"),
        OPT_END()
};

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

        page_size = sysconf(_SC_PAGE_SIZE);

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

        /* CPU and PID are mutually exclusive */
        if (target_pid != -1 && profile_cpu != -1) {
                printf("WARNING: PID switch overriding CPU\n");
                sleep(1);
                profile_cpu = -1;
        }

        if (!nr_counters)
                nr_counters = 1;

        symbol_conf.priv_size = (sizeof(struct sym_entry) +
                                 (nr_counters + 1) * sizeof(unsigned long));
        if (symbol_conf.vmlinux_name == NULL)
                symbol_conf.try_vmlinux_path = true;
        if (symbol__init() < 0)
                return -1;

        if (delay_secs < 1)
                delay_secs = 1;

        parse_source(sym_filter_entry);

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

        /*
         * Fill in the ones not specifically initialized via -c:
         */
        for (counter = 0; counter < nr_counters; counter++) {
                if (attrs[counter].sample_period)
                        continue;

                attrs[counter].sample_period = default_interval;
        }

        nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
        assert(nr_cpus <= MAX_NR_CPUS);
        assert(nr_cpus >= 0);

        if (target_pid != -1 || profile_cpu != -1)
                nr_cpus = 1;

        get_term_dimensions(&winsize);
        if (print_entries == 0) {
                update_print_entries(&winsize);
                signal(SIGWINCH, sig_winch_handler);
        }

        return __cmd_top();
}