4 * Builtin record command: Record the profile of a workload
5 * (or a CPU, or a PID) into the perf.data output file - for
6 * later analysis via perf report.
8 #define _FILE_OFFSET_BITS 64
14 #include "util/build-id.h"
15 #include "util/util.h"
16 #include "util/parse-options.h"
17 #include "util/parse-events.h"
19 #include "util/header.h"
20 #include "util/event.h"
21 #include "util/debug.h"
22 #include "util/session.h"
23 #include "util/symbol.h"
24 #include "util/cpumap.h"
29 static int *fd
[MAX_NR_CPUS
][MAX_COUNTERS
];
31 static long default_interval
= 0;
33 static int nr_cpus
= 0;
34 static unsigned int page_size
;
35 static unsigned int mmap_pages
= 128;
36 static int freq
= 1000;
38 static int pipe_output
= 0;
39 static const char *output_name
= "perf.data";
41 static unsigned int realtime_prio
= 0;
42 static bool raw_samples
= false;
43 static bool system_wide
= false;
44 static int profile_cpu
= -1;
45 static pid_t target_pid
= -1;
46 static pid_t target_tid
= -1;
47 static pid_t
*all_tids
= NULL
;
48 static int thread_num
= 0;
49 static pid_t child_pid
= -1;
50 static bool inherit
= true;
51 static bool force
= false;
52 static bool append_file
= false;
53 static bool call_graph
= false;
54 static bool inherit_stat
= false;
55 static bool no_samples
= false;
56 static bool sample_address
= false;
57 static bool multiplex
= false;
58 static int multiplex_fd
= -1;
60 static long samples
= 0;
61 static struct timeval last_read
;
62 static struct timeval this_read
;
64 static u64 bytes_written
= 0;
66 static struct pollfd
*event_array
;
68 static int nr_poll
= 0;
69 static int nr_cpu
= 0;
71 static int file_new
= 1;
72 static off_t post_processing_offset
;
74 static struct perf_session
*session
;
83 static struct mmap_data
*mmap_array
[MAX_NR_CPUS
][MAX_COUNTERS
];
85 static unsigned long mmap_read_head(struct mmap_data
*md
)
87 struct perf_event_mmap_page
*pc
= md
->base
;
96 static void mmap_write_tail(struct mmap_data
*md
, unsigned long tail
)
98 struct perf_event_mmap_page
*pc
= md
->base
;
101 * ensure all reads are done before we write the tail out.
104 pc
->data_tail
= tail
;
107 static void write_output(void *buf
, size_t size
)
110 int ret
= write(output
, buf
, size
);
113 die("failed to write");
118 bytes_written
+= ret
;
122 static int process_synthesized_event(event_t
*event
,
123 struct perf_session
*self __used
)
125 write_output(event
, event
->header
.size
);
129 static void mmap_read(struct mmap_data
*md
)
131 unsigned int head
= mmap_read_head(md
);
132 unsigned int old
= md
->prev
;
133 unsigned char *data
= md
->base
+ page_size
;
138 gettimeofday(&this_read
, NULL
);
141 * If we're further behind than half the buffer, there's a chance
142 * the writer will bite our tail and mess up the samples under us.
144 * If we somehow ended up ahead of the head, we got messed up.
146 * In either case, truncate and restart at head.
153 timersub(&this_read
, &last_read
, &iv
);
154 msecs
= iv
.tv_sec
*1000 + iv
.tv_usec
/1000;
156 fprintf(stderr
, "WARNING: failed to keep up with mmap data."
157 " Last read %lu msecs ago.\n", msecs
);
160 * head points to a known good entry, start there.
165 last_read
= this_read
;
172 if ((old
& md
->mask
) + size
!= (head
& md
->mask
)) {
173 buf
= &data
[old
& md
->mask
];
174 size
= md
->mask
+ 1 - (old
& md
->mask
);
177 write_output(buf
, size
);
180 buf
= &data
[old
& md
->mask
];
184 write_output(buf
, size
);
187 mmap_write_tail(md
, old
);
190 static volatile int done
= 0;
191 static volatile int signr
= -1;
193 static void sig_handler(int sig
)
199 static void sig_atexit(void)
202 kill(child_pid
, SIGTERM
);
207 signal(signr
, SIG_DFL
);
208 kill(getpid(), signr
);
213 static struct perf_header_attr
*get_header_attr(struct perf_event_attr
*a
, int nr
)
215 struct perf_header_attr
*h_attr
;
217 if (nr
< session
->header
.attrs
) {
218 h_attr
= session
->header
.attr
[nr
];
220 h_attr
= perf_header_attr__new(a
);
222 if (perf_header__add_attr(&session
->header
, h_attr
) < 0) {
223 perf_header_attr__delete(h_attr
);
231 static void create_counter(int counter
, int cpu
)
233 char *filter
= filters
[counter
];
234 struct perf_event_attr
*attr
= attrs
+ counter
;
235 struct perf_header_attr
*h_attr
;
236 int track
= !counter
; /* only the first counter needs these */
246 attr
->read_format
= PERF_FORMAT_TOTAL_TIME_ENABLED
|
247 PERF_FORMAT_TOTAL_TIME_RUNNING
|
250 attr
->sample_type
|= PERF_SAMPLE_IP
| PERF_SAMPLE_TID
;
253 attr
->sample_type
|= PERF_SAMPLE_ID
;
256 attr
->sample_type
|= PERF_SAMPLE_PERIOD
;
258 attr
->sample_freq
= freq
;
262 attr
->sample_freq
= 0;
265 attr
->inherit_stat
= 1;
268 attr
->sample_type
|= PERF_SAMPLE_ADDR
;
271 attr
->sample_type
|= PERF_SAMPLE_CALLCHAIN
;
274 attr
->sample_type
|= PERF_SAMPLE_TIME
;
275 attr
->sample_type
|= PERF_SAMPLE_RAW
;
276 attr
->sample_type
|= PERF_SAMPLE_CPU
;
281 attr
->inherit
= inherit
;
282 if (target_pid
== -1 && !system_wide
) {
284 attr
->enable_on_exec
= 1;
287 for (thread_index
= 0; thread_index
< thread_num
; thread_index
++) {
289 fd
[nr_cpu
][counter
][thread_index
] = sys_perf_event_open(attr
,
290 all_tids
[thread_index
], cpu
, group_fd
, 0);
292 if (fd
[nr_cpu
][counter
][thread_index
] < 0) {
295 if (err
== EPERM
|| err
== EACCES
)
296 die("Permission error - are you root?\n"
297 "\t Consider tweaking"
298 " /proc/sys/kernel/perf_event_paranoid.\n");
299 else if (err
== ENODEV
&& profile_cpu
!= -1) {
300 die("No such device - did you specify"
301 " an out-of-range profile CPU?\n");
305 * If it's cycles then fall back to hrtimer
306 * based cpu-clock-tick sw counter, which
307 * is always available even if no PMU support:
309 if (attr
->type
== PERF_TYPE_HARDWARE
310 && attr
->config
== PERF_COUNT_HW_CPU_CYCLES
) {
313 warning(" ... trying to fall back to cpu-clock-ticks\n");
314 attr
->type
= PERF_TYPE_SOFTWARE
;
315 attr
->config
= PERF_COUNT_SW_CPU_CLOCK
;
319 error("perfcounter syscall returned with %d (%s)\n",
320 fd
[nr_cpu
][counter
][thread_index
], strerror(err
));
322 #if defined(__i386__) || defined(__x86_64__)
323 if (attr
->type
== PERF_TYPE_HARDWARE
&& err
== EOPNOTSUPP
)
324 die("No hardware sampling interrupt available."
325 " No APIC? If so then you can boot the kernel"
326 " with the \"lapic\" boot parameter to"
327 " force-enable it.\n");
330 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
334 h_attr
= get_header_attr(attr
, counter
);
339 if (memcmp(&h_attr
->attr
, attr
, sizeof(*attr
))) {
340 fprintf(stderr
, "incompatible append\n");
345 if (read(fd
[nr_cpu
][counter
][thread_index
], &read_data
, sizeof(read_data
)) == -1) {
346 perror("Unable to read perf file descriptor\n");
350 if (perf_header_attr__add_id(h_attr
, read_data
.id
) < 0) {
351 pr_warning("Not enough memory to add id\n");
355 assert(fd
[nr_cpu
][counter
][thread_index
] >= 0);
356 fcntl(fd
[nr_cpu
][counter
][thread_index
], F_SETFL
, O_NONBLOCK
);
359 * First counter acts as the group leader:
361 if (group
&& group_fd
== -1)
362 group_fd
= fd
[nr_cpu
][counter
][thread_index
];
363 if (multiplex
&& multiplex_fd
== -1)
364 multiplex_fd
= fd
[nr_cpu
][counter
][thread_index
];
366 if (multiplex
&& fd
[nr_cpu
][counter
][thread_index
] != multiplex_fd
) {
368 ret
= ioctl(fd
[nr_cpu
][counter
][thread_index
], PERF_EVENT_IOC_SET_OUTPUT
, multiplex_fd
);
371 event_array
[nr_poll
].fd
= fd
[nr_cpu
][counter
][thread_index
];
372 event_array
[nr_poll
].events
= POLLIN
;
375 mmap_array
[nr_cpu
][counter
][thread_index
].counter
= counter
;
376 mmap_array
[nr_cpu
][counter
][thread_index
].prev
= 0;
377 mmap_array
[nr_cpu
][counter
][thread_index
].mask
= mmap_pages
*page_size
- 1;
378 mmap_array
[nr_cpu
][counter
][thread_index
].base
= mmap(NULL
, (mmap_pages
+1)*page_size
,
379 PROT_READ
|PROT_WRITE
, MAP_SHARED
, fd
[nr_cpu
][counter
][thread_index
], 0);
380 if (mmap_array
[nr_cpu
][counter
][thread_index
].base
== MAP_FAILED
) {
381 error("failed to mmap with %d (%s)\n", errno
, strerror(errno
));
386 if (filter
!= NULL
) {
387 ret
= ioctl(fd
[nr_cpu
][counter
][thread_index
],
388 PERF_EVENT_IOC_SET_FILTER
, filter
);
390 error("failed to set filter with %d (%s)\n", errno
,
398 static void open_counters(int cpu
)
403 for (counter
= 0; counter
< nr_counters
; counter
++)
404 create_counter(counter
, cpu
);
409 static int process_buildids(void)
411 u64 size
= lseek(output
, 0, SEEK_CUR
);
416 session
->fd
= output
;
417 return __perf_session__process_events(session
, post_processing_offset
,
418 size
- post_processing_offset
,
419 size
, &build_id__mark_dso_hit_ops
);
422 static void atexit_header(void)
424 session
->header
.data_size
+= bytes_written
;
427 perf_header__write(&session
->header
, output
, true);
430 static int __cmd_record(int argc
, const char **argv
)
437 unsigned long waking
= 0;
438 int child_ready_pipe
[2], go_pipe
[2];
439 const bool forks
= argc
> 0;
442 page_size
= sysconf(_SC_PAGE_SIZE
);
445 signal(SIGCHLD
, sig_handler
);
446 signal(SIGINT
, sig_handler
);
448 if (forks
&& (pipe(child_ready_pipe
) < 0 || pipe(go_pipe
) < 0)) {
449 perror("failed to create pipes");
453 if (!strcmp(output_name
, "-"))
455 else if (!stat(output_name
, &st
) && st
.st_size
) {
458 pr_err("Error, output file %s exists, use -A "
459 "to append or -f to overwrite.\n",
464 char oldname
[PATH_MAX
];
465 snprintf(oldname
, sizeof(oldname
), "%s.old",
468 rename(output_name
, oldname
);
474 flags
= O_CREAT
|O_RDWR
;
481 output
= STDOUT_FILENO
;
483 output
= open(output_name
, flags
, S_IRUSR
| S_IWUSR
);
485 perror("failed to create output file");
489 session
= perf_session__new(output_name
, O_WRONLY
, force
);
490 if (session
== NULL
) {
491 pr_err("Not enough memory for reading perf file header\n");
496 err
= perf_header__read(session
, output
);
502 perf_header__set_feat(&session
->header
, HEADER_TRACE_INFO
);
504 for (i
= 0; i
< nr_counters
; i
++) {
505 if (attrs
[i
].sample_type
& PERF_SAMPLE_RAW
) {
506 perf_header__set_feat(&session
->header
, HEADER_TRACE_INFO
);
512 atexit(atexit_header
);
517 perror("failed to fork");
524 close(child_ready_pipe
[0]);
526 fcntl(go_pipe
[0], F_SETFD
, FD_CLOEXEC
);
529 * Do a dummy execvp to get the PLT entry resolved,
530 * so we avoid the resolver overhead on the real
533 execvp("", (char **)argv
);
536 * Tell the parent we're ready to go
538 close(child_ready_pipe
[1]);
541 * Wait until the parent tells us to go.
543 if (read(go_pipe
[0], &buf
, 1) == -1)
544 perror("unable to read pipe");
546 execvp(argv
[0], (char **)argv
);
552 if (!system_wide
&& target_tid
== -1 && target_pid
== -1)
553 all_tids
[0] = child_pid
;
555 close(child_ready_pipe
[1]);
558 * wait for child to settle
560 if (read(child_ready_pipe
[0], &buf
, 1) == -1) {
561 perror("unable to read pipe");
564 close(child_ready_pipe
[0]);
567 if ((!system_wide
&& !inherit
) || profile_cpu
!= -1) {
568 open_counters(profile_cpu
);
570 nr_cpus
= read_cpu_map();
571 for (i
= 0; i
< nr_cpus
; i
++)
572 open_counters(cpumap
[i
]);
576 err
= perf_header__write_pipe(output
);
579 } else if (file_new
) {
580 err
= perf_header__write(&session
->header
, output
, false);
585 post_processing_offset
= lseek(output
, 0, SEEK_CUR
);
588 err
= event__synthesize_attrs(&session
->header
,
589 process_synthesized_event
,
592 pr_err("Couldn't synthesize attrs.\n");
597 err
= event__synthesize_kernel_mmap(process_synthesized_event
,
600 err
= event__synthesize_kernel_mmap(process_synthesized_event
,
603 pr_err("Couldn't record kernel reference relocation symbol.\n");
607 err
= event__synthesize_modules(process_synthesized_event
, session
);
609 pr_err("Couldn't record kernel reference relocation symbol.\n");
613 if (!system_wide
&& profile_cpu
== -1)
614 event__synthesize_thread(target_tid
, process_synthesized_event
,
617 event__synthesize_threads(process_synthesized_event
, session
);
620 struct sched_param param
;
622 param
.sched_priority
= realtime_prio
;
623 if (sched_setscheduler(0, SCHED_FIFO
, ¶m
)) {
624 pr_err("Could not set realtime priority.\n");
639 for (i
= 0; i
< nr_cpu
; i
++) {
640 for (counter
= 0; counter
< nr_counters
; counter
++) {
642 thread
< thread_num
; thread
++) {
643 if (mmap_array
[i
][counter
][thread
].base
)
644 mmap_read(&mmap_array
[i
][counter
][thread
]);
650 if (hits
== samples
) {
653 err
= poll(event_array
, nr_poll
, -1);
658 for (i
= 0; i
< nr_cpu
; i
++) {
660 counter
< nr_counters
;
665 ioctl(fd
[i
][counter
][thread
],
666 PERF_EVENT_IOC_DISABLE
);
672 fprintf(stderr
, "[ perf record: Woken up %ld times to write data ]\n", waking
);
675 * Approximate RIP event size: 24 bytes.
678 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
679 (double)bytes_written
/ 1024.0 / 1024.0,
686 static const char * const record_usage
[] = {
687 "perf record [<options>] [<command>]",
688 "perf record [<options>] -- <command> [<options>]",
692 static const struct option options
[] = {
693 OPT_CALLBACK('e', "event", NULL
, "event",
694 "event selector. use 'perf list' to list available events",
696 OPT_CALLBACK(0, "filter", NULL
, "filter",
697 "event filter", parse_filter
),
698 OPT_INTEGER('p', "pid", &target_pid
,
699 "record events on existing process id"),
700 OPT_INTEGER('t', "tid", &target_tid
,
701 "record events on existing thread id"),
702 OPT_INTEGER('r', "realtime", &realtime_prio
,
703 "collect data with this RT SCHED_FIFO priority"),
704 OPT_BOOLEAN('R', "raw-samples", &raw_samples
,
705 "collect raw sample records from all opened counters"),
706 OPT_BOOLEAN('a', "all-cpus", &system_wide
,
707 "system-wide collection from all CPUs"),
708 OPT_BOOLEAN('A', "append", &append_file
,
709 "append to the output file to do incremental profiling"),
710 OPT_INTEGER('C', "profile_cpu", &profile_cpu
,
711 "CPU to profile on"),
712 OPT_BOOLEAN('f', "force", &force
,
713 "overwrite existing data file"),
714 OPT_LONG('c', "count", &default_interval
,
715 "event period to sample"),
716 OPT_STRING('o', "output", &output_name
, "file",
718 OPT_BOOLEAN('i', "inherit", &inherit
,
719 "child tasks inherit counters"),
720 OPT_INTEGER('F', "freq", &freq
,
721 "profile at this frequency"),
722 OPT_INTEGER('m', "mmap-pages", &mmap_pages
,
723 "number of mmap data pages"),
724 OPT_BOOLEAN('g', "call-graph", &call_graph
,
725 "do call-graph (stack chain/backtrace) recording"),
726 OPT_INCR('v', "verbose", &verbose
,
727 "be more verbose (show counter open errors, etc)"),
728 OPT_BOOLEAN('s', "stat", &inherit_stat
,
729 "per thread counts"),
730 OPT_BOOLEAN('d', "data", &sample_address
,
732 OPT_BOOLEAN('n', "no-samples", &no_samples
,
734 OPT_BOOLEAN('M', "multiplex", &multiplex
,
735 "multiplex counter output in a single channel"),
739 int cmd_record(int argc
, const char **argv
, const char *prefix __used
)
744 argc
= parse_options(argc
, argv
, options
, record_usage
,
745 PARSE_OPT_STOP_AT_NON_OPTION
);
746 if (!argc
&& target_pid
== -1 && target_tid
== -1 &&
747 !system_wide
&& profile_cpu
== -1)
748 usage_with_options(record_usage
, options
);
754 attrs
[0].type
= PERF_TYPE_HARDWARE
;
755 attrs
[0].config
= PERF_COUNT_HW_CPU_CYCLES
;
758 if (target_pid
!= -1) {
759 target_tid
= target_pid
;
760 thread_num
= find_all_tid(target_pid
, &all_tids
);
761 if (thread_num
<= 0) {
762 fprintf(stderr
, "Can't find all threads of pid %d\n",
764 usage_with_options(record_usage
, options
);
767 all_tids
=malloc(sizeof(pid_t
));
771 all_tids
[0] = target_tid
;
775 for (i
= 0; i
< MAX_NR_CPUS
; i
++) {
776 for (j
= 0; j
< MAX_COUNTERS
; j
++) {
777 fd
[i
][j
] = malloc(sizeof(int)*thread_num
);
778 mmap_array
[i
][j
] = zalloc(
779 sizeof(struct mmap_data
)*thread_num
);
780 if (!fd
[i
][j
] || !mmap_array
[i
][j
])
784 event_array
= malloc(
785 sizeof(struct pollfd
)*MAX_NR_CPUS
*MAX_COUNTERS
*thread_num
);
790 * User specified count overrides default frequency.
792 if (default_interval
)
795 default_interval
= freq
;
797 fprintf(stderr
, "frequency and count are zero, aborting\n");
801 for (counter
= 0; counter
< nr_counters
; counter
++) {
802 if (attrs
[counter
].sample_period
)
805 attrs
[counter
].sample_period
= default_interval
;
808 return __cmd_record(argc
, argv
);