/*
* kerneltop.c: show top kernel functions - performance counters showcase
Build with:
make -C Documentation/perf_counter/
Sample output:
------------------------------------------------------------------------------
KernelTop: 2669 irqs/sec [NMI, 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 "util/util.h"
#include <getopt.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 int nr_counters = 0;
static __u64 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 tid = -1;
static int profile_cpu = -1;
static int nr_cpus = 0;
static int nmi = 1;
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 *vmlinux;
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 int scale;
struct source_line {
uint64_t EIP;
unsigned long count;
char *line;
struct source_line *next;
};
static struct source_line *lines;
static struct source_line **lines_tail;
static const unsigned int default_count[] = {
1000000,
1000000,
10000,
10000,
1000000,
10000,
};
static char *hw_event_names[] = {
"CPU cycles",
"instructions",
"cache references",
"cache misses",
"branches",
"branch misses",
"bus cycles",
};
static char *sw_event_names[] = {
"cpu clock ticks",
"task clock ticks",
"pagefaults",
"context switches",
"CPU migrations",
"minor faults",
"major faults",
};
struct event_symbol {
__u64 event;
char *symbol;
};
static struct event_symbol event_symbols[] = {
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES), "cpu-cycles", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES), "cycles", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_INSTRUCTIONS), "instructions", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_REFERENCES), "cache-references", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_MISSES), "cache-misses", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_BRANCH_INSTRUCTIONS), "branch-instructions", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_BRANCH_INSTRUCTIONS), "branches", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_BRANCH_MISSES), "branch-misses", },
{EID(PERF_TYPE_HARDWARE, PERF_COUNT_BUS_CYCLES), "bus-cycles", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_CLOCK), "cpu-clock", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK), "task-clock", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS), "page-faults", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS), "faults", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS_MIN), "minor-faults", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS_MAJ), "major-faults", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES), "context-switches", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES), "cs", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS), "cpu-migrations", },
{EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS), "migrations", },
};
#define __PERF_COUNTER_FIELD(config, name) \
((config & PERF_COUNTER_##name##_MASK) >> PERF_COUNTER_##name##_SHIFT)
#define PERF_COUNTER_RAW(config) __PERF_COUNTER_FIELD(config, RAW)
#define PERF_COUNTER_CONFIG(config) __PERF_COUNTER_FIELD(config, CONFIG)
#define PERF_COUNTER_TYPE(config) __PERF_COUNTER_FIELD(config, TYPE)
#define PERF_COUNTER_ID(config) __PERF_COUNTER_FIELD(config, EVENT)
static void display_events_help(void)
{
unsigned int i;
__u64 e;
printf(
" -e EVENT --event=EVENT # symbolic-name abbreviations");
for (i = 0; i < ARRAY_SIZE(event_symbols); i++) {
int type, id;
e = event_symbols[i].event;
type = PERF_COUNTER_TYPE(e);
id = PERF_COUNTER_ID(e);
printf("\n %d:%d: %-20s",
type, id, event_symbols[i].symbol);
}
printf("\n"
" rNNN: raw PMU events (eventsel+umask)\n\n");
}
static void display_help(void)
{
printf(
"Usage: kerneltop [<options>]\n"
" Or: kerneltop -S [<options>] COMMAND [ARGS]\n\n"
"KernelTop Options (up to %d event types can be specified at once):\n\n",
MAX_COUNTERS);
display_events_help();
printf(
" -c CNT --count=CNT # event period to sample\n\n"
" -C CPU --cpu=CPU # CPU (-1 for all) [default: -1]\n"
" -p PID --pid=PID # PID of sampled task (-1 for all) [default: -1]\n\n"
" -l # show scale factor for RR events\n"
" -d delay --delay=<seconds> # sampling/display delay [default: 2]\n"
" -f CNT --filter=CNT # min-event-count filter [default: 100]\n\n"
" -r prio --realtime=<prio> # event acquisition runs with SCHED_FIFO policy\n"
" -s symbol --symbol=<symbol> # function to be showed annotated one-shot\n"
" -x path --vmlinux=<path> # the vmlinux binary, required for -s use\n"
" -z --zero # zero counts after display\n"
" -D --dump_symtab # dump symbol table to stderr on startup\n"
" -m pages --mmap_pages=<pages> # number of mmap data pages\n"
" -M --mmap_info # print mmap info stream\n"
" -U --munmap_info # print munmap info stream\n"
);
exit(0);
}
static char *event_name(int ctr)
{
__u64 config = event_id[ctr];
int type = PERF_COUNTER_TYPE(config);
int id = PERF_COUNTER_ID(config);
static char buf[32];
if (PERF_COUNTER_RAW(config)) {
sprintf(buf, "raw 0x%llx", PERF_COUNTER_CONFIG(config));
return buf;
}
switch (type) {
case PERF_TYPE_HARDWARE:
if (id < PERF_HW_EVENTS_MAX)
return hw_event_names[id];
return "unknown-hardware";
case PERF_TYPE_SOFTWARE:
if (id < PERF_SW_EVENTS_MAX)
return sw_event_names[id];
return "unknown-software";
default:
break;
}
return "unknown";
}
/*
* Each event can have multiple symbolic names.
* Symbolic names are (almost) exactly matched.
*/
static __u64 match_event_symbols(char *str)
{
__u64 config, id;
int type;
unsigned int i;
if (sscanf(str, "r%llx", &config) == 1)
return config | PERF_COUNTER_RAW_MASK;
if (sscanf(str, "%d:%llu", &type, &id) == 2)
return EID(type, id);
for (i = 0; i < ARRAY_SIZE(event_symbols); i++) {
if (!strncmp(str, event_symbols[i].symbol,
strlen(event_symbols[i].symbol)))
return event_symbols[i].event;
}
return ~0ULL;
}
static int parse_events(char *str)
{
__u64 config;
again:
if (nr_counters == MAX_COUNTERS)
return -1;
config = match_event_symbols(str);
if (config == ~0ULL)
return -1;
event_id[nr_counters] = config;
nr_counters++;
str = strstr(str, ",");
if (str) {
str++;
goto again;
}
return 0;
}
/*
* 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;
struct source_line *source;
};
#define MAX_SYMS 100000
static int sym_table_count;
struct sym_entry *sym_filter_entry;
static struct sym_entry sym_table[MAX_SYMS];
static void show_details(struct sym_entry *sym);
/*
* 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%% [%s, ",
events_per_sec,
100.0 - (100.0*((events_per_sec-kevents_per_sec)/events_per_sec)),
nmi ? "NMI" : "IRQ");
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 (tid != -1)
printf(" (tid: %d", tid);
else
printf(" (all");
if (profile_cpu != -1)
printf(", cpu: %d)\n", profile_cpu);
else {
if (tid != -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);
}
if (sym_filter_entry)
show_details(sym_filter_entry);
{
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);
}
}
/*
* Source lines
*/
static void parse_vmlinux(char *filename)
{
FILE *file;
char command[PATH_MAX*2];
if (!filename)
return;
sprintf(command, "objdump --start-address=0x%016lx --stop-address=0x%016lx -dS %s", filter_start, filter_end, filename);
file = popen(command, "r");
if (!file)
return;
lines_tail = &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;
*lines_tail = src;
lines_tail = &src->next;
if (strlen(src->line)>8 && src->line[8] == ':')
src->EIP = strtoull(src->line, NULL, 16);
if (strlen(src->line)>8 && src->line[16] == ':')
src->EIP = strtoull(src->line, NULL, 16);
}
pclose(file);
}
static void record_precise_ip(uint64_t ip)
{
struct source_line *line;
for (line = lines; line; line = line->next) {
if (line->EIP == ip)
line->count++;
if (line->EIP > ip)
break;
}
}
static void lookup_sym_in_vmlinux(struct sym_entry *sym)
{
struct source_line *line;
char pattern[PATH_MAX];
sprintf(pattern, "<%s>:", sym->sym);
for (line = lines; line; line = line->next) {
if (strstr(line->line, pattern)) {
sym->source = line;
break;
}
}
}
static void show_lines(struct source_line *line_queue, int line_queue_count)
{
int i;
struct source_line *line;
line = line_queue;
for (i = 0; i < line_queue_count; i++) {
printf("%8li\t%s\n", line->count, line->line);
line = line->next;
}
}
#define TRACE_COUNT 3
static void show_details(struct sym_entry *sym)
{
struct source_line *line;
struct source_line *line_queue = NULL;
int displayed = 0;
int line_queue_count = 0;
if (!sym->source)
lookup_sym_in_vmlinux(sym);
if (!sym->source)
return;
printf("Showing details for %s\n", sym->sym);
line = sym->source;
while (line) {
if (displayed && strstr(line->line, ">:"))
break;
if (!line_queue_count)
line_queue = line;
line_queue_count ++;
if (line->count >= count_filter) {
show_lines(line_queue, 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 = 0;
displayed++;
if (displayed > 300)
break;
line = line->next;
}
}
/*
* 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;
record_precise_ip(ip);
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);
}
static void process_options(int argc, char **argv)
{
int error = 0, counter;
for (;;) {
int option_index = 0;
/** Options for getopt */
static struct option long_options[] = {
{"count", required_argument, NULL, 'c'},
{"cpu", required_argument, NULL, 'C'},
{"delay", required_argument, NULL, 'd'},
{"dump_symtab", no_argument, NULL, 'D'},
{"event", required_argument, NULL, 'e'},
{"filter", required_argument, NULL, 'f'},
{"group", required_argument, NULL, 'g'},
{"help", no_argument, NULL, 'h'},
{"nmi", required_argument, NULL, 'n'},
{"mmap_info", no_argument, NULL, 'M'},
{"mmap_pages", required_argument, NULL, 'm'},
{"munmap_info", no_argument, NULL, 'U'},
{"pid", required_argument, NULL, 'p'},
{"realtime", required_argument, NULL, 'r'},
{"scale", no_argument, NULL, 'l'},
{"symbol", required_argument, NULL, 's'},
{"stat", no_argument, NULL, 'S'},
{"vmlinux", required_argument, NULL, 'x'},
{"zero", no_argument, NULL, 'z'},
{"freq", required_argument, NULL, 'F'},
{NULL, 0, NULL, 0 }
};
int c = getopt_long(argc, argv, "+:ac:C:d:De:f:g:hln:m:p:r:s:Sx:zMUF:",
long_options, &option_index);
if (c == -1)
break;
switch (c) {
case 'a': system_wide = 1; break;
case 'c': default_interval = atoi(optarg); break;
case 'C':
/* CPU and PID are mutually exclusive */
if (tid != -1) {
printf("WARNING: CPU switch overriding PID\n");
sleep(1);
tid = -1;
}
profile_cpu = atoi(optarg); break;
case 'd': delay_secs = atoi(optarg); break;
case 'D': dump_symtab = 1; break;
case 'e': error = parse_events(optarg); break;
case 'f': count_filter = atoi(optarg); break;
case 'g': group = atoi(optarg); break;
case 'h': display_help(); break;
case 'l': scale = 1; break;
case 'n': nmi = atoi(optarg); break;
case 'p':
/* CPU and PID are mutually exclusive */
if (profile_cpu != -1) {
printf("WARNING: PID switch overriding CPU\n");
sleep(1);
profile_cpu = -1;
}
tid = atoi(optarg); break;
case 'r': realtime_prio = atoi(optarg); break;
case 's': sym_filter = strdup(optarg); break;
case 'x': vmlinux = strdup(optarg); break;
case 'z': zero = 1; break;
case 'm': mmap_pages = atoi(optarg); break;
case 'M': use_mmap = 1; break;
case 'U': use_munmap = 1; break;
case 'F': freq = 1; default_interval = atoi(optarg); break;
default: error = 1; break;
}
}
if (error)
display_help();
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;
}
}
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, tid;
};
struct mmap_event {
struct perf_event_header header;
__u32 pid, tid;
__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];
int cmd_top(int argc, char **argv, const char *prefix)
{
struct perf_counter_hw_event hw_event;
pthread_t thread;
int i, counter, group_fd, nr_poll = 0;
unsigned int cpu;
int ret;
page_size = sysconf(_SC_PAGE_SIZE);
process_options(argc, argv);
nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
assert(nr_cpus <= MAX_NR_CPUS);
assert(nr_cpus >= 0);
if (tid != -1 || profile_cpu != -1)
nr_cpus = 1;
parse_symbols();
if (vmlinux && sym_filter_entry)
parse_vmlinux(vmlinux);
for (i = 0; i < nr_cpus; i++) {
group_fd = -1;
for (counter = 0; counter < nr_counters; counter++) {
cpu = profile_cpu;
if (tid == -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 = nmi;
hw_event.mmap = use_mmap;
hw_event.munmap = use_munmap;
hw_event.freq = freq;
fd[i][counter] = sys_perf_counter_open(&hw_event, tid, 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;
}
