/*
* kerneltop.c: show top kernel functions - performance counters showcase
Build with:
make -C Documentation/perf_counter/
Sample output:
------------------------------------------------------------------------------
KernelTop: 2669 irqs/sec [cache-misses/cache-refs], (all, cpu: 2)
------------------------------------------------------------------------------
weight RIP kernel function
______ ________________ _______________
35.20 - ffffffff804ce74b : skb_copy_and_csum_dev
33.00 - ffffffff804cb740 : sock_alloc_send_skb
31.26 - ffffffff804ce808 : skb_push
22.43 - ffffffff80510004 : tcp_established_options
19.00 - ffffffff8027d250 : find_get_page
15.76 - ffffffff804e4fc9 : eth_type_trans
15.20 - ffffffff804d8baa : dst_release
14.86 - ffffffff804cf5d8 : skb_release_head_state
14.00 - ffffffff802217d5 : read_hpet
12.00 - ffffffff804ffb7f : __ip_local_out
11.97 - ffffffff804fc0c8 : ip_local_deliver_finish
8.54 - ffffffff805001a3 : ip_queue_xmit
*/
/*
* 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 "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include <assert.h>
#include <fcntl.h>
#include <stdio.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 system_wide = 0;
static __u64 default_event_id[MAX_COUNTERS] = {
EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK),
EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES),
EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS),
EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS),
EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES),
EID(PERF_TYPE_HARDWARE, PERF_COUNT_INSTRUCTIONS),
EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_REFERENCES),
EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_MISSES),
};
static int default_interval = 100000;
static int event_count[MAX_COUNTERS];
static int fd[MAX_NR_CPUS][MAX_COUNTERS];
static __u64 count_filter = 100;
static int target_pid = -1;
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 use_mmap = 0;
static int use_munmap = 0;
static int freq = 0;
static char *sym_filter;
static unsigned long filter_start;
static unsigned long filter_end;
static int delay_secs = 2;
static int zero;
static int dump_symtab;
static const unsigned int default_count[] = {
1000000,
1000000,
10000,
10000,
1000000,
10000,
};
/*
* Symbols
*/
static uint64_t min_ip;
static uint64_t max_ip = -1ll;
struct sym_entry {
unsigned long long addr;
char *sym;
unsigned long count[MAX_COUNTERS];
int skip;
};
#define MAX_SYMS 100000
static int sym_table_count;
struct sym_entry *sym_filter_entry;
static struct sym_entry sym_table[MAX_SYMS];
/*
* Ordering weight: count-1 * count-2 * ... / count-n
*/
static double sym_weight(const struct sym_entry *sym)
{
double weight;
int counter;
weight = sym->count[0];
for (counter = 1; counter < nr_counters-1; counter++)
weight *= sym->count[counter];
weight /= (sym->count[counter] + 1);
return weight;
}
static int compare(const void *__sym1, const void *__sym2)
{
const struct sym_entry *sym1 = __sym1, *sym2 = __sym2;
return sym_weight(sym1) < sym_weight(sym2);
}
static long events;
static long userspace_events;
static const char CONSOLE_CLEAR[] = "[H[2J";
static struct sym_entry tmp[MAX_SYMS];
static void print_sym_table(void)
{
int i, j, active_count, printed;
int counter;
float events_per_sec = events/delay_secs;
float kevents_per_sec = (events-userspace_events)/delay_secs;
float sum_kevents = 0.0;
events = userspace_events = 0;
/* Iterate over symbol table and copy/tally/decay active symbols. */
for (i = 0, active_count = 0; i < sym_table_count; i++) {
if (sym_table[i].count[0]) {
tmp[active_count++] = sym_table[i];
sum_kevents += sym_table[i].count[0];
for (j = 0; j < nr_counters; j++)
sym_table[i].count[j] = zero ? 0 : sym_table[i].count[j] * 7 / 8;
}
}
qsort(tmp, active_count + 1, sizeof(tmp[0]), compare);
write(1, CONSOLE_CLEAR, strlen(CONSOLE_CLEAR));
printf(
"------------------------------------------------------------------------------\n");
printf( " KernelTop:%8.0f irqs/sec kernel:%4.1f%% [",
events_per_sec,
100.0 - (100.0*((events_per_sec-kevents_per_sec)/events_per_sec)));
if (nr_counters == 1)
printf("%d ", event_count[0]);
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 (nr_counters == 1)
printf(" events pcnt");
else
printf(" weight events pcnt");
printf(" RIP kernel function\n"
" ______ ______ _____ ________________ _______________\n\n"
);
for (i = 0, printed = 0; i < active_count; i++) {
float pcnt;
if (++printed > 18 || tmp[i].count[0] < count_filter)
break;
pcnt = 100.0 - (100.0*((sum_kevents-tmp[i].count[0])/sum_kevents));
if (nr_counters == 1)
printf("%19.2f - %4.1f%% - %016llx : %s\n",
sym_weight(tmp + i),
pcnt, tmp[i].addr, tmp[i].sym);
else
printf("%8.1f %10ld - %4.1f%% - %016llx : %s\n",
sym_weight(tmp + i),
tmp[i].count[0],
pcnt, tmp[i].addr, tmp[i].sym);
}
{
struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
if (poll(&stdin_poll, 1, 0) == 1) {
printf("key pressed - exiting.\n");
exit(0);
}
}
}
static void *display_thread(void *arg)
{
printf("KernelTop refresh period: %d seconds\n", delay_secs);
while (!sleep(delay_secs))
print_sym_table();
return NULL;
}
static int read_symbol(FILE *in, struct sym_entry *s)
{
static int filter_match = 0;
char *sym, stype;
char str[500];
int rc, pos;
rc = fscanf(in, "%llx %c %499s", &s->addr, &stype, str);
if (rc == EOF)
return -1;
assert(rc == 3);
/* skip until end of line: */
pos = strlen(str);
do {
rc = fgetc(in);
if (rc == '\n' || rc == EOF || pos >= 499)
break;
str[pos] = rc;
pos++;
} while (1);
str[pos] = 0;
sym = str;
/* Filter out known duplicates and non-text symbols. */
if (!strcmp(sym, "_text"))
return 1;
if (!min_ip && !strcmp(sym, "_stext"))
return 1;
if (!strcmp(sym, "_etext") || !strcmp(sym, "_sinittext"))
return 1;
if (stype != 'T' && stype != 't')
return 1;
if (!strncmp("init_module", sym, 11) || !strncmp("cleanup_module", sym, 14))
return 1;
if (strstr(sym, "_text_start") || strstr(sym, "_text_end"))
return 1;
s->sym = malloc(strlen(str)+1);
assert(s->sym);
strcpy((char *)s->sym, str);
s->skip = 0;
/* Tag events to be skipped. */
if (!strcmp("default_idle", s->sym) || !strcmp("cpu_idle", s->sym))
s->skip = 1;
else if (!strcmp("enter_idle", s->sym) || !strcmp("exit_idle", s->sym))
s->skip = 1;
else if (!strcmp("mwait_idle", s->sym))
s->skip = 1;
if (filter_match == 1) {
filter_end = s->addr;
filter_match = -1;
if (filter_end - filter_start > 10000) {
printf("hm, too large filter symbol <%s> - skipping.\n",
sym_filter);
printf("symbol filter start: %016lx\n", filter_start);
printf(" end: %016lx\n", filter_end);
filter_end = filter_start = 0;
sym_filter = NULL;
sleep(1);
}
}
if (filter_match == 0 && sym_filter && !strcmp(s->sym, sym_filter)) {
filter_match = 1;
filter_start = s->addr;
}
return 0;
}
static int compare_addr(const void *__sym1, const void *__sym2)
{
const struct sym_entry *sym1 = __sym1, *sym2 = __sym2;
return sym1->addr > sym2->addr;
}
static void sort_symbol_table(void)
{
int i, dups;
do {
qsort(sym_table, sym_table_count, sizeof(sym_table[0]), compare_addr);
for (i = 0, dups = 0; i < sym_table_count; i++) {
if (sym_table[i].addr == sym_table[i+1].addr) {
sym_table[i+1].addr = -1ll;
dups++;
}
}
sym_table_count -= dups;
} while(dups);
}
static void parse_symbols(void)
{
struct sym_entry *last;
FILE *kallsyms = fopen("/proc/kallsyms", "r");
if (!kallsyms) {
printf("Could not open /proc/kallsyms - no CONFIG_KALLSYMS_ALL=y?\n");
exit(-1);
}
while (!feof(kallsyms)) {
if (read_symbol(kallsyms, &sym_table[sym_table_count]) == 0) {
sym_table_count++;
assert(sym_table_count <= MAX_SYMS);
}
}
sort_symbol_table();
min_ip = sym_table[0].addr;
max_ip = sym_table[sym_table_count-1].addr;
last = sym_table + sym_table_count++;
last->addr = -1ll;
last->sym = "<end>";
if (filter_end) {
int count;
for (count=0; count < sym_table_count; count ++) {
if (!strcmp(sym_table[count].sym, sym_filter)) {
sym_filter_entry = &sym_table[count];
break;
}
}
}
if (dump_symtab) {
int i;
for (i = 0; i < sym_table_count; i++)
fprintf(stderr, "%llx %s\n",
sym_table[i].addr, sym_table[i].sym);
}
}
#define TRACE_COUNT 3
/*
* Binary search in the histogram table and record the hit:
*/
static void record_ip(uint64_t ip, int counter)
{
int left_idx, middle_idx, right_idx, idx;
unsigned long left, middle, right;
left_idx = 0;
right_idx = sym_table_count-1;
assert(ip <= max_ip && ip >= min_ip);
while (left_idx + 1 < right_idx) {
middle_idx = (left_idx + right_idx) / 2;
left = sym_table[ left_idx].addr;
middle = sym_table[middle_idx].addr;
right = sym_table[ right_idx].addr;
if (!(left <= middle && middle <= right)) {
printf("%016lx...\n%016lx...\n%016lx\n", left, middle, right);
printf("%d %d %d\n", left_idx, middle_idx, right_idx);
}
assert(left <= middle && middle <= right);
if (!(left <= ip && ip <= right)) {
printf(" left: %016lx\n", left);
printf(" ip: %016lx\n", (unsigned long)ip);
printf("right: %016lx\n", right);
}
assert(left <= ip && ip <= right);
/*
* [ left .... target .... middle .... right ]
* => right := middle
*/
if (ip < middle) {
right_idx = middle_idx;
continue;
}
/*
* [ left .... middle ... target ... right ]
* => left := middle
*/
left_idx = middle_idx;
}
idx = left_idx;
if (!sym_table[idx].skip)
sym_table[idx].count[counter]++;
else events--;
}
static void process_event(uint64_t ip, int counter)
{
events++;
if (ip < min_ip || ip > max_ip) {
userspace_events++;
return;
}
record_ip(ip, counter);
}
struct mmap_data {
int counter;
void *base;
unsigned int mask;
unsigned int prev;
};
static unsigned int mmap_read_head(struct mmap_data *md)
{
struct perf_counter_mmap_page *pc = md->base;
int head;
head = pc->data_head;
rmb();
return head;
}
struct timeval last_read, this_read;
static void mmap_read(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 screw up the events 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;) {
struct ip_event {
struct perf_event_header header;
__u64 ip;
__u32 pid, target_pid;
};
struct mmap_event {
struct perf_event_header header;
__u32 pid, target_pid;
__u64 start;
__u64 len;
__u64 pgoff;
char filename[PATH_MAX];
};
typedef union event_union {
struct perf_event_header header;
struct ip_event ip;
struct mmap_event mmap;
} event_t;
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.misc & PERF_EVENT_MISC_OVERFLOW) {
if (event->header.type & PERF_RECORD_IP)
process_event(event->ip.ip, md->counter);
} else {
switch (event->header.type) {
case PERF_EVENT_MMAP:
case PERF_EVENT_MUNMAP:
printf("%s: %Lu %Lu %Lu %s\n",
event->header.type == PERF_EVENT_MMAP
? "mmap" : "munmap",
event->mmap.start,
event->mmap.len,
event->mmap.pgoff,
event->mmap.filename);
break;
}
}
}
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 int __cmd_top(void)
{
struct perf_counter_hw_event hw_event;
pthread_t thread;
int i, counter, group_fd, nr_poll = 0;
unsigned int cpu;
int ret;
for (i = 0; i < nr_cpus; i++) {
group_fd = -1;
for (counter = 0; counter < nr_counters; counter++) {
cpu = profile_cpu;
if (target_pid == -1 && profile_cpu == -1)
cpu = i;
memset(&hw_event, 0, sizeof(hw_event));
hw_event.config = event_id[counter];
hw_event.irq_period = event_count[counter];
hw_event.record_type = PERF_RECORD_IP | PERF_RECORD_TID;
hw_event.nmi = 1;
hw_event.mmap = use_mmap;
hw_event.munmap = use_munmap;
hw_event.freq = freq;
fd[i][counter] = sys_perf_counter_open(&hw_event, target_pid, cpu, group_fd, 0);
if (fd[i][counter] < 0) {
int err = errno;
printf("kerneltop error: syscall returned with %d (%s)\n",
fd[i][counter], strerror(err));
if (err == EPERM)
printf("Are you root?\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) {
printf("kerneltop error: failed to mmap with %d (%s)\n",
errno, strerror(errno));
exit(-1);
}
}
}
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, ¶m)) {
printf("Could not set realtime priority.\n");
exit(-1);
}
}
while (1) {
int hits = events;
for (i = 0; i < nr_cpus; i++) {
for (counter = 0; counter < nr_counters; counter++)
mmap_read(&mmap_array[i][counter]);
}
if (hits == events)
ret = poll(event_array, nr_poll, 100);
}
return 0;
}
static const char * const top_usage[] = {
"perf top [<options>]",
NULL
};
static char events_help_msg[EVENTS_HELP_MAX];
static const struct option options[] = {
OPT_CALLBACK('e', "event", NULL, "event",
events_help_msg, 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_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_STRING('s', "sym-filter", &sym_filter, "pattern",
"only display symbols matchig this pattern"),
OPT_BOOLEAN('z', "zero", &group,
"zero history across updates"),
OPT_BOOLEAN('M', "use-mmap", &use_mmap,
"track mmap events"),
OPT_BOOLEAN('U', "use-munmap", &use_munmap,
"track munmap events"),
OPT_INTEGER('F', "--freq", &freq,
"profile at this frequency"),
OPT_END()
};
int cmd_top(int argc, const char **argv, const char *prefix)
{
int counter;
page_size = sysconf(_SC_PAGE_SIZE);
create_events_help(events_help_msg);
memcpy(event_id, default_event_id, sizeof(default_event_id));
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;
event_id[0] = 0;
}
for (counter = 0; counter < nr_counters; counter++) {
if (event_count[counter])
continue;
event_count[counter] = 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;
parse_symbols();
return __cmd_top();
}
