linux/tools/perf/builtin-record.c

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/*
* builtin-record.c
*
* Builtin record command: Record the profile of a workload
* (or a CPU, or a PID) into the perf.data output file - for
* later analysis via perf report.
*/
#include "builtin.h"
#include "perf.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/string.h"
#include "util/header.h"
#include <unistd.h>
#include <sched.h>
#define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a)-1)
#define __ALIGN_MASK(x, mask) (((x)+(mask))&~(mask))
static int fd[MAX_NR_CPUS][MAX_COUNTERS];
static long default_interval = 100000;
static int nr_cpus = 0;
static unsigned int page_size;
static unsigned int mmap_pages = 128;
static int freq = 0;
static int output;
static const char *output_name = "perf.data";
static int group = 0;
static unsigned int realtime_prio = 0;
static int system_wide = 0;
static pid_t target_pid = -1;
static int inherit = 1;
static int force = 0;
static int append_file = 0;
static int call_graph = 0;
static int verbose = 0;
static int inherit_stat = 0;
static int no_samples = 0;
static int sample_address = 0;
static long samples;
static struct timeval last_read;
static struct timeval this_read;
static u64 bytes_written;
static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
static int nr_poll;
static int nr_cpu;
static int file_new = 1;
struct perf_header *header;
struct mmap_event {
struct perf_event_header header;
u32 pid;
u32 tid;
u64 start;
u64 len;
u64 pgoff;
char filename[PATH_MAX];
};
struct comm_event {
struct perf_event_header header;
u32 pid;
u32 tid;
char comm[16];
};
struct mmap_data {
int counter;
void *base;
unsigned int mask;
unsigned int prev;
};
static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
static unsigned long mmap_read_head(struct mmap_data *md)
{
struct perf_counter_mmap_page *pc = md->base;
long head;
head = pc->data_head;
rmb();
return head;
}
static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
{
struct perf_counter_mmap_page *pc = md->base;
/*
* ensure all reads are done before we write the tail out.
*/
/* mb(); */
pc->data_tail = tail;
}
static void write_output(void *buf, size_t size)
{
while (size) {
int ret = write(output, buf, size);
if (ret < 0)
die("failed to write");
size -= ret;
buf += ret;
bytes_written += ret;
}
}
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;
unsigned long size;
void *buf;
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 < 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;
if (old != head)
samples++;
size = head - old;
if ((old & md->mask) + size != (head & md->mask)) {
buf = &data[old & md->mask];
size = md->mask + 1 - (old & md->mask);
old += size;
write_output(buf, size);
}
buf = &data[old & md->mask];
size = head - old;
old += size;
write_output(buf, size);
md->prev = old;
mmap_write_tail(md, old);
}
static volatile int done = 0;
static volatile int signr = -1;
static void sig_handler(int sig)
{
done = 1;
signr = sig;
}
static void sig_atexit(void)
{
if (signr == -1)
return;
signal(signr, SIG_DFL);
kill(getpid(), signr);
}
static void pid_synthesize_comm_event(pid_t pid, int full)
{
struct comm_event comm_ev;
char filename[PATH_MAX];
char bf[BUFSIZ];
int fd;
size_t size;
char *field, *sep;
DIR *tasks;
struct dirent dirent, *next;
snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
fd = open(filename, O_RDONLY);
if (fd < 0) {
/*
* We raced with a task exiting - just return:
*/
if (verbose)
fprintf(stderr, "couldn't open %s\n", filename);
return;
}
if (read(fd, bf, sizeof(bf)) < 0) {
fprintf(stderr, "couldn't read %s\n", filename);
exit(EXIT_FAILURE);
}
close(fd);
/* 9027 (cat) R 6747 9027 6747 34816 9027 ... */
memset(&comm_ev, 0, sizeof(comm_ev));
field = strchr(bf, '(');
if (field == NULL)
goto out_failure;
sep = strchr(++field, ')');
if (sep == NULL)
goto out_failure;
size = sep - field;
memcpy(comm_ev.comm, field, size++);
comm_ev.pid = pid;
comm_ev.header.type = PERF_EVENT_COMM;
size = ALIGN(size, sizeof(u64));
comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
if (!full) {
comm_ev.tid = pid;
write_output(&comm_ev, comm_ev.header.size);
return;
}
snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
tasks = opendir(filename);
while (!readdir_r(tasks, &dirent, &next) && next) {
char *end;
pid = strtol(dirent.d_name, &end, 10);
if (*end)
continue;
comm_ev.tid = pid;
write_output(&comm_ev, comm_ev.header.size);
}
closedir(tasks);
return;
out_failure:
fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
filename);
exit(EXIT_FAILURE);
}
static void pid_synthesize_mmap_samples(pid_t pid)
{
char filename[PATH_MAX];
FILE *fp;
snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
fp = fopen(filename, "r");
if (fp == NULL) {
/*
* We raced with a task exiting - just return:
*/
if (verbose)
fprintf(stderr, "couldn't open %s\n", filename);
return;
}
while (1) {
char bf[BUFSIZ], *pbf = bf;
struct mmap_event mmap_ev = {
.header = { .type = PERF_EVENT_MMAP },
};
int n;
size_t size;
if (fgets(bf, sizeof(bf), fp) == NULL)
break;
/* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */
n = hex2u64(pbf, &mmap_ev.start);
if (n < 0)
continue;
pbf += n + 1;
n = hex2u64(pbf, &mmap_ev.len);
if (n < 0)
continue;
pbf += n + 3;
if (*pbf == 'x') { /* vm_exec */
char *execname = strchr(bf, '/');
/* Catch VDSO */
if (execname == NULL)
execname = strstr(bf, "[vdso]");
if (execname == NULL)
continue;
size = strlen(execname);
execname[size - 1] = '\0'; /* Remove \n */
memcpy(mmap_ev.filename, execname, size);
size = ALIGN(size, sizeof(u64));
mmap_ev.len -= mmap_ev.start;
mmap_ev.header.size = (sizeof(mmap_ev) -
(sizeof(mmap_ev.filename) - size));
mmap_ev.pid = pid;
mmap_ev.tid = pid;
write_output(&mmap_ev, mmap_ev.header.size);
}
}
fclose(fp);
}
static void synthesize_all(void)
{
DIR *proc;
struct dirent dirent, *next;
proc = opendir("/proc");
while (!readdir_r(proc, &dirent, &next) && next) {
char *end;
pid_t pid;
pid = strtol(dirent.d_name, &end, 10);
if (*end) /* only interested in proper numerical dirents */
continue;
pid_synthesize_comm_event(pid, 1);
pid_synthesize_mmap_samples(pid);
}
closedir(proc);
}
static int group_fd;
static struct perf_header_attr *get_header_attr(struct perf_counter_attr *a, int nr)
{
struct perf_header_attr *h_attr;
if (nr < header->attrs) {
h_attr = header->attr[nr];
} else {
h_attr = perf_header_attr__new(a);
perf_header__add_attr(header, h_attr);
}
return h_attr;
}
static void create_counter(int counter, int cpu, pid_t pid)
{
struct perf_counter_attr *attr = attrs + counter;
struct perf_header_attr *h_attr;
int track = !counter; /* only the first counter needs these */
struct {
u64 count;
u64 time_enabled;
u64 time_running;
u64 id;
} read_data;
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
PERF_FORMAT_TOTAL_TIME_RUNNING |
PERF_FORMAT_ID;
attr->sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
if (freq) {
attr->sample_type |= PERF_SAMPLE_PERIOD;
attr->freq = 1;
attr->sample_freq = freq;
}
if (no_samples)
attr->sample_freq = 0;
if (inherit_stat)
attr->inherit_stat = 1;
if (sample_address)
attr->sample_type |= PERF_SAMPLE_ADDR;
if (call_graph)
attr->sample_type |= PERF_SAMPLE_CALLCHAIN;
perf_counter: Fix/complete ftrace event records sampling This patch implements the kernel side support for ftrace event record sampling. A new counter sampling attribute is added: PERF_SAMPLE_TP_RECORD which requests ftrace events record sampling. In this case if a PERF_TYPE_TRACEPOINT counter is active and a tracepoint fires, we emit the tracepoint binary record to the perfcounter event buffer, as a sample. Result, after setting PERF_SAMPLE_TP_RECORD attribute from perf record: perf record -f -F 1 -a -e workqueue:workqueue_execution perf report -D 0x21e18 [0x48]: event: 9 . . ... raw event: size 72 bytes . 0000: 09 00 00 00 01 00 48 00 d0 c7 00 81 ff ff ff ff ......H........ . 0010: 0a 00 00 00 0a 00 00 00 21 00 00 00 00 00 00 00 ........!...... . 0020: 2b 00 01 02 0a 00 00 00 0a 00 00 00 65 76 65 6e +...........eve . 0030: 74 73 2f 31 00 00 00 00 00 00 00 00 0a 00 00 00 ts/1........... . 0040: e0 b1 31 81 ff ff ff ff ....... . 0x21e18 [0x48]: PERF_EVENT_SAMPLE (IP, 1): 10: 0xffffffff8100c7d0 period: 33 The raw ftrace binary record starts at offset 0020. Translation: struct trace_entry { type = 0x2b = 43; flags = 1; preempt_count = 2; pid = 0xa = 10; tgid = 0xa = 10; } thread_comm = "events/1" thread_pid = 0xa = 10; func = 0xffffffff8131b1e0 = flush_to_ldisc() What will come next? - Userspace support ('perf trace'), 'flight data recorder' mode for perf trace, etc. - The unconditional copy from the profiling callback brings some costs however if someone wants no such sampling to occur, and needs to be fixed in the future. For that we need to have an instant access to the perf counter attribute. This is a matter of a flag to add in the struct ftrace_event. - Take care of the events recursivity! Don't ever try to record a lock event for example, it seems some locking is used in the profiling fast path and lead to a tracing recursivity. That will be fixed using raw spinlock or recursivity protection. - [...] - Profit! :-) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-06 23:25:54 +00:00
attr->mmap = track;
attr->comm = track;
attr->inherit = (cpu < 0) && inherit;
attr->disabled = 1;
try_again:
fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
if (fd[nr_cpu][counter] < 0) {
int err = errno;
if (err == EPERM)
die("Permission error - 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[nr_cpu][counter], strerror(err));
die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
exit(-1);
}
h_attr = get_header_attr(attr, counter);
if (!file_new) {
if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
fprintf(stderr, "incompatible append\n");
exit(-1);
}
}
if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
perror("Unable to read perf file descriptor\n");
exit(-1);
}
perf_header_attr__add_id(h_attr, read_data.id);
assert(fd[nr_cpu][counter] >= 0);
fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
/*
* First counter acts as the group leader:
*/
if (group && group_fd == -1)
group_fd = fd[nr_cpu][counter];
event_array[nr_poll].fd = fd[nr_cpu][counter];
event_array[nr_poll].events = POLLIN;
nr_poll++;
mmap_array[nr_cpu][counter].counter = counter;
mmap_array[nr_cpu][counter].prev = 0;
mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
error("failed to mmap with %d (%s)\n", errno, strerror(errno));
exit(-1);
}
ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
}
static void open_counters(int cpu, pid_t pid)
{
int counter;
group_fd = -1;
for (counter = 0; counter < nr_counters; counter++)
create_counter(counter, cpu, pid);
nr_cpu++;
}
static void atexit_header(void)
{
header->data_size += bytes_written;
perf_header__write(header, output);
}
static int __cmd_record(int argc, const char **argv)
{
int i, counter;
struct stat st;
pid_t pid = 0;
int flags;
int ret;
page_size = sysconf(_SC_PAGE_SIZE);
nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
assert(nr_cpus <= MAX_NR_CPUS);
assert(nr_cpus >= 0);
atexit(sig_atexit);
signal(SIGCHLD, sig_handler);
signal(SIGINT, sig_handler);
if (!stat(output_name, &st) && st.st_size) {
if (!force && !append_file) {
fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
output_name);
exit(-1);
}
} else {
append_file = 0;
}
flags = O_CREAT|O_RDWR;
if (append_file)
file_new = 0;
else
flags |= O_TRUNC;
output = open(output_name, flags, S_IRUSR|S_IWUSR);
if (output < 0) {
perror("failed to create output file");
exit(-1);
}
if (!file_new)
header = perf_header__read(output);
else
header = perf_header__new();
atexit(atexit_header);
if (!system_wide) {
pid = target_pid;
if (pid == -1)
pid = getpid();
open_counters(-1, pid);
} else for (i = 0; i < nr_cpus; i++)
open_counters(i, target_pid);
if (file_new)
perf_header__write(header, output);
if (!system_wide) {
pid_synthesize_comm_event(pid, 0);
pid_synthesize_mmap_samples(pid);
} else
synthesize_all();
if (target_pid == -1 && argc) {
pid = fork();
if (pid < 0)
perror("failed to fork");
if (!pid) {
if (execvp(argv[0], (char **)argv)) {
perror(argv[0]);
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);
}
}
for (;;) {
int hits = samples;
for (i = 0; i < nr_cpu; i++) {
for (counter = 0; counter < nr_counters; counter++)
mmap_read(&mmap_array[i][counter]);
}
if (hits == samples) {
if (done)
break;
ret = poll(event_array, nr_poll, 100);
}
}
/*
* Approximate RIP event size: 24 bytes.
*/
fprintf(stderr,
"[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
(double)bytes_written / 1024.0 / 1024.0,
output_name,
bytes_written / 24);
return 0;
}
static const char * const record_usage[] = {
"perf record [<options>] [<command>]",
"perf record [<options>] -- <command> [<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('p', "pid", &target_pid,
"record events on existing pid"),
OPT_INTEGER('r', "realtime", &realtime_prio,
"collect data with this RT SCHED_FIFO priority"),
OPT_BOOLEAN('a', "all-cpus", &system_wide,
"system-wide collection from all CPUs"),
OPT_BOOLEAN('A', "append", &append_file,
"append to the output file to do incremental profiling"),
OPT_BOOLEAN('f', "force", &force,
"overwrite existing data file"),
OPT_LONG('c', "count", &default_interval,
"event period to sample"),
OPT_STRING('o', "output", &output_name, "file",
"output file name"),
OPT_BOOLEAN('i', "inherit", &inherit,
"child tasks inherit counters"),
OPT_INTEGER('F', "freq", &freq,
"profile at this frequency"),
OPT_INTEGER('m', "mmap-pages", &mmap_pages,
"number of mmap data pages"),
OPT_BOOLEAN('g', "call-graph", &call_graph,
"do call-graph (stack chain/backtrace) recording"),
OPT_BOOLEAN('v', "verbose", &verbose,
"be more verbose (show counter open errors, etc)"),
OPT_BOOLEAN('s', "stat", &inherit_stat,
"per thread counts"),
OPT_BOOLEAN('d', "data", &sample_address,
"Sample addresses"),
OPT_BOOLEAN('n', "no-samples", &no_samples,
"don't sample"),
OPT_END()
};
int cmd_record(int argc, const char **argv, const char *prefix __used)
{
int counter;
argc = parse_options(argc, argv, options, record_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (!argc && target_pid == -1 && !system_wide)
usage_with_options(record_usage, options);
if (!nr_counters) {
nr_counters = 1;
attrs[0].type = PERF_TYPE_HARDWARE;
attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
}
for (counter = 0; counter < nr_counters; counter++) {
if (attrs[counter].sample_period)
continue;
attrs[counter].sample_period = default_interval;
}
return __cmd_record(argc, argv);
}