linux/tools/perf/builtin-top.c
Tim Blechmann dc79959aaf perf top: Fix --delay_secs 0 division by zero
Add delay_secs sanity check to handle_keypress,
this fixes a division by zero crash.

Signed-off-by: Tim Blechmann <tim@klingt.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4AD9EBFD.106@klingt.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-19 09:52:39 +02:00

1216 lines
27 KiB
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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>
*
* 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/symbol.h"
#include "util/color.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 = 100000;
static int count_filter = 5;
static int print_entries = 15;
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 = 0;
static int delay_secs = 2;
static int zero;
static int dump_symtab;
/*
* 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
*/
static u64 min_ip;
static u64 max_ip = -1ll;
struct sym_entry {
struct rb_node rb_node;
struct list_head node;
unsigned long count[MAX_COUNTERS];
unsigned long snap_count;
double weight;
int skip;
struct source_line *source;
struct source_line *lines;
struct source_line **lines_tail;
pthread_mutex_t source_lock;
};
/*
* Source functions
*/
static void parse_source(struct sym_entry *syme)
{
struct symbol *sym;
struct module *module;
struct section *section = NULL;
FILE *file;
char command[PATH_MAX*2];
const char *path = vmlinux_name;
u64 start, end, len;
if (!syme)
return;
if (syme->lines) {
pthread_mutex_lock(&syme->source_lock);
goto out_assign;
}
sym = (struct symbol *)(syme + 1);
module = sym->module;
if (module)
path = module->path;
if (!path)
return;
start = sym->obj_start;
if (!start)
start = sym->start;
if (module) {
section = module->sections->find_section(module->sections, ".text");
if (section)
start -= section->vma;
}
end = start + sym->end - sym->start + 1;
len = sym->end - sym->start;
sprintf(command, "objdump --start-address=0x%016Lx --stop-address=0x%016Lx -dS %s", start, end, path);
file = popen(command, "r");
if (!file)
return;
pthread_mutex_lock(&syme->source_lock);
syme->lines_tail = &syme->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;
*syme->lines_tail = src;
syme->lines_tail = &src->next;
if (strlen(src->line)>8 && src->line[8] == ':') {
src->eip = strtoull(src->line, NULL, 16);
if (section)
src->eip += section->vma;
}
if (strlen(src->line)>8 && src->line[16] == ':') {
src->eip = strtoull(src->line, NULL, 16);
if (section)
src->eip += section->vma;
}
}
pclose(file);
out_assign:
sym_filter_entry = syme;
pthread_mutex_unlock(&syme->source_lock);
}
static void __zero_source_counters(struct sym_entry *syme)
{
int i;
struct source_line *line;
line = syme->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->source_lock))
return;
if (!syme->source)
goto out_unlock;
for (line = syme->lines; line; line = line->next) {
if (line->eip == ip) {
line->count[counter]++;
break;
}
if (line->eip > ip)
break;
}
out_unlock:
pthread_mutex_unlock(&syme->source_lock);
}
static void lookup_sym_source(struct sym_entry *syme)
{
struct symbol *symbol = (struct symbol *)(syme + 1);
struct source_line *line;
char pattern[PATH_MAX];
char *idx;
sprintf(pattern, "<%s>:", symbol->name);
if (symbol->module) {
idx = strstr(pattern, "\t");
if (idx)
*idx = 0;
}
pthread_mutex_lock(&syme->source_lock);
for (line = syme->lines; line; line = line->next) {
if (strstr(line->line, pattern)) {
syme->source = line;
break;
}
}
pthread_mutex_unlock(&syme->source_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->source)
lookup_sym_source(syme);
if (!syme->source)
return;
symbol = (struct symbol *)(syme + 1);
printf("Showing %s for %s\n", event_name(sym_counter), symbol->name);
printf(" Events Pcnt (>=%d%%)\n", sym_pcnt_filter);
pthread_mutex_lock(&syme->source_lock);
line = syme->source;
while (line) {
total += line->count[sym_counter];
line = line->next;
}
line = syme->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->source_lock);
if (more)
printf("%d lines not displayed, maybe increase display entries [e]\n", more);
}
/*
* Symbols will be added here in record_ip 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[] = "";
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;
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) {
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(
"------------------------------------------------------------------------------\n");
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("------------------------------------------------------------------------------\n\n");
if (sym_filter_entry) {
show_details(sym_filter_entry);
return;
}
if (nr_counters == 1)
printf(" samples pcnt");
else
printf(" weight samples pcnt");
if (verbose)
printf(" RIP ");
printf(" kernel function\n");
printf(" %s _______ _____",
nr_counters == 1 ? " " : "______");
if (verbose)
printf(" ________________");
printf(" _______________\n\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 = (struct symbol *)(syme + 1);
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->name);
if (sym->module)
printf("\t[%s]", sym->module->name);
printf("\n");
}
}
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->source_lock);
__zero_source_counters(syme);
*target = NULL;
pthread_mutex_unlock(&syme->source_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 = (struct symbol *)(syme + 1);
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 = (struct symbol *)(sym_filter_entry+1);
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 (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[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':
return 1;
case 'E':
case 'w':
return nr_counters > 1 ? 1 : 0;
case 'F':
case 's':
case 'S':
return 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)");
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 'q':
case 'Q':
printf("exiting.\n");
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->source_lock);
sym_filter_entry = NULL;
__zero_source_counters(syme);
pthread_mutex_unlock(&syme->source_lock);
}
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 dso *self, 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 = dso__sym_priv(self, sym);
pthread_mutex_init(&syme->source_lock, 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;
}
}
return 0;
}
static int parse_symbols(void)
{
struct rb_node *node;
struct symbol *sym;
int use_modules = vmlinux_name ? 1 : 0;
kernel_dso = dso__new("[kernel]", sizeof(struct sym_entry));
if (kernel_dso == NULL)
return -1;
if (dso__load_kernel(kernel_dso, vmlinux_name, symbol_filter, verbose, use_modules) <= 0)
goto out_delete_dso;
node = rb_first(&kernel_dso->syms);
sym = rb_entry(node, struct symbol, rb_node);
min_ip = sym->start;
node = rb_last(&kernel_dso->syms);
sym = rb_entry(node, struct symbol, rb_node);
max_ip = sym->end;
if (dump_symtab)
dso__fprintf(kernel_dso, stderr);
return 0;
out_delete_dso:
dso__delete(kernel_dso);
kernel_dso = NULL;
return -1;
}
/*
* Binary search in the histogram table and record the hit:
*/
static void record_ip(u64 ip, int counter)
{
struct symbol *sym = dso__find_symbol(kernel_dso, ip);
if (sym != NULL) {
struct sym_entry *syme = dso__sym_priv(kernel_dso, sym);
if (!syme->skip) {
syme->count[counter]++;
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);
return;
}
}
samples--;
}
static void process_event(u64 ip, int counter, int user)
{
samples++;
if (user) {
userspace_samples++;
return;
}
record_ip(ip, counter);
}
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;
}
struct timeval last_read, this_read;
static void mmap_read_counter(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;
gettimeofday(&this_read, NULL);
/*
* 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) {
struct timeval iv;
unsigned long msecs;
timersub(&this_read, &last_read, &iv);
msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
fprintf(stderr, "WARNING: failed to keep up with mmap data."
" Last read %lu msecs ago.\n", msecs);
/*
* head points to a known good entry, start there.
*/
old = head;
}
last_read = this_read;
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;
}
old += size;
if (event->header.type == PERF_RECORD_SAMPLE) {
int user =
(event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK) == PERF_RECORD_MISC_USER;
process_event(event->ip.ip, md->counter, user);
}
}
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 mmap_read(void)
{
int i, counter;
for (i = 0; i < nr_cpus; i++) {
for (counter = 0; counter < nr_counters; counter++)
mmap_read_counter(&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;
attr->freq = freq;
attr->inherit = (cpu < 0) && inherit;
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)
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;
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);
mmap_read();
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;
mmap_read();
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", &vmlinux_name, "file", "vmlinux pathname"),
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('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;
symbol__init();
page_size = sysconf(_SC_PAGE_SIZE);
argc = parse_options(argc, argv, options, top_usage, 0);
if (argc)
usage_with_options(top_usage, options);
if (freq) {
default_interval = freq;
freq = 1;
}
/* 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;
if (delay_secs < 1)
delay_secs = 1;
parse_symbols();
parse_source(sym_filter_entry);
/*
* 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;
return __cmd_top();
}