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"
34 static int *fd
[MAX_NR_CPUS
][MAX_COUNTERS
];
36 static unsigned int user_interval
= UINT_MAX
;
37 static long default_interval
= 0;
39 static int nr_cpus
= 0;
40 static unsigned int page_size
;
41 static unsigned int mmap_pages
= 128;
42 static unsigned int user_freq
= UINT_MAX
;
43 static int freq
= 1000;
45 static int pipe_output
= 0;
46 static const char *output_name
= "perf.data";
48 static unsigned int realtime_prio
= 0;
49 static bool raw_samples
= false;
50 static bool system_wide
= false;
51 static int profile_cpu
= -1;
52 static pid_t target_pid
= -1;
53 static pid_t target_tid
= -1;
54 static pid_t
*all_tids
= NULL
;
55 static int thread_num
= 0;
56 static pid_t child_pid
= -1;
57 static bool inherit
= true;
58 static enum write_mode_t write_mode
= WRITE_FORCE
;
59 static bool call_graph
= false;
60 static bool inherit_stat
= false;
61 static bool no_samples
= false;
62 static bool sample_address
= false;
63 static bool multiplex
= false;
64 static int multiplex_fd
= -1;
66 static long samples
= 0;
67 static struct timeval last_read
;
68 static struct timeval this_read
;
70 static u64 bytes_written
= 0;
72 static struct pollfd
*event_array
;
74 static int nr_poll
= 0;
75 static int nr_cpu
= 0;
77 static int file_new
= 1;
78 static off_t post_processing_offset
;
80 static struct perf_session
*session
;
89 static struct mmap_data
*mmap_array
[MAX_NR_CPUS
][MAX_COUNTERS
];
91 static unsigned long mmap_read_head(struct mmap_data
*md
)
93 struct perf_event_mmap_page
*pc
= md
->base
;
102 static void mmap_write_tail(struct mmap_data
*md
, unsigned long tail
)
104 struct perf_event_mmap_page
*pc
= md
->base
;
107 * ensure all reads are done before we write the tail out.
110 pc
->data_tail
= tail
;
113 static void advance_output(size_t size
)
115 bytes_written
+= size
;
118 static void write_output(void *buf
, size_t size
)
121 int ret
= write(output
, buf
, size
);
124 die("failed to write");
129 bytes_written
+= ret
;
133 static int process_synthesized_event(event_t
*event
,
134 struct perf_session
*self __used
)
136 write_output(event
, event
->header
.size
);
140 static void mmap_read(struct mmap_data
*md
)
142 unsigned int head
= mmap_read_head(md
);
143 unsigned int old
= md
->prev
;
144 unsigned char *data
= md
->base
+ page_size
;
149 gettimeofday(&this_read
, NULL
);
152 * If we're further behind than half the buffer, there's a chance
153 * the writer will bite our tail and mess up the samples under us.
155 * If we somehow ended up ahead of the head, we got messed up.
157 * In either case, truncate and restart at head.
164 timersub(&this_read
, &last_read
, &iv
);
165 msecs
= iv
.tv_sec
*1000 + iv
.tv_usec
/1000;
167 fprintf(stderr
, "WARNING: failed to keep up with mmap data."
168 " Last read %lu msecs ago.\n", msecs
);
171 * head points to a known good entry, start there.
176 last_read
= this_read
;
183 if ((old
& md
->mask
) + size
!= (head
& md
->mask
)) {
184 buf
= &data
[old
& md
->mask
];
185 size
= md
->mask
+ 1 - (old
& md
->mask
);
188 write_output(buf
, size
);
191 buf
= &data
[old
& md
->mask
];
195 write_output(buf
, size
);
198 mmap_write_tail(md
, old
);
201 static volatile int done
= 0;
202 static volatile int signr
= -1;
204 static void sig_handler(int sig
)
210 static void sig_atexit(void)
213 kill(child_pid
, SIGTERM
);
218 signal(signr
, SIG_DFL
);
219 kill(getpid(), signr
);
224 static struct perf_header_attr
*get_header_attr(struct perf_event_attr
*a
, int nr
)
226 struct perf_header_attr
*h_attr
;
228 if (nr
< session
->header
.attrs
) {
229 h_attr
= session
->header
.attr
[nr
];
231 h_attr
= perf_header_attr__new(a
);
233 if (perf_header__add_attr(&session
->header
, h_attr
) < 0) {
234 perf_header_attr__delete(h_attr
);
242 static void create_counter(int counter
, int cpu
)
244 char *filter
= filters
[counter
];
245 struct perf_event_attr
*attr
= attrs
+ counter
;
246 struct perf_header_attr
*h_attr
;
247 int track
= !counter
; /* only the first counter needs these */
257 attr
->read_format
= PERF_FORMAT_TOTAL_TIME_ENABLED
|
258 PERF_FORMAT_TOTAL_TIME_RUNNING
|
261 attr
->sample_type
|= PERF_SAMPLE_IP
| PERF_SAMPLE_TID
;
264 attr
->sample_type
|= PERF_SAMPLE_ID
;
267 * We default some events to a 1 default interval. But keep
268 * it a weak assumption overridable by the user.
270 if (!attr
->sample_period
|| (user_freq
!= UINT_MAX
&&
271 user_interval
!= UINT_MAX
)) {
273 attr
->sample_type
|= PERF_SAMPLE_PERIOD
;
275 attr
->sample_freq
= freq
;
277 attr
->sample_period
= default_interval
;
282 attr
->sample_freq
= 0;
285 attr
->inherit_stat
= 1;
288 attr
->sample_type
|= PERF_SAMPLE_ADDR
;
291 attr
->sample_type
|= PERF_SAMPLE_CALLCHAIN
;
294 attr
->sample_type
|= PERF_SAMPLE_TIME
;
295 attr
->sample_type
|= PERF_SAMPLE_RAW
;
296 attr
->sample_type
|= PERF_SAMPLE_CPU
;
301 attr
->inherit
= inherit
;
302 if (target_pid
== -1 && !system_wide
) {
304 attr
->enable_on_exec
= 1;
307 for (thread_index
= 0; thread_index
< thread_num
; thread_index
++) {
309 fd
[nr_cpu
][counter
][thread_index
] = sys_perf_event_open(attr
,
310 all_tids
[thread_index
], cpu
, group_fd
, 0);
312 if (fd
[nr_cpu
][counter
][thread_index
] < 0) {
315 if (err
== EPERM
|| err
== EACCES
)
316 die("Permission error - are you root?\n"
317 "\t Consider tweaking"
318 " /proc/sys/kernel/perf_event_paranoid.\n");
319 else if (err
== ENODEV
&& profile_cpu
!= -1) {
320 die("No such device - did you specify"
321 " an out-of-range profile CPU?\n");
325 * If it's cycles then fall back to hrtimer
326 * based cpu-clock-tick sw counter, which
327 * is always available even if no PMU support:
329 if (attr
->type
== PERF_TYPE_HARDWARE
330 && attr
->config
== PERF_COUNT_HW_CPU_CYCLES
) {
333 warning(" ... trying to fall back to cpu-clock-ticks\n");
334 attr
->type
= PERF_TYPE_SOFTWARE
;
335 attr
->config
= PERF_COUNT_SW_CPU_CLOCK
;
339 error("perfcounter syscall returned with %d (%s)\n",
340 fd
[nr_cpu
][counter
][thread_index
], strerror(err
));
342 #if defined(__i386__) || defined(__x86_64__)
343 if (attr
->type
== PERF_TYPE_HARDWARE
&& err
== EOPNOTSUPP
)
344 die("No hardware sampling interrupt available."
345 " No APIC? If so then you can boot the kernel"
346 " with the \"lapic\" boot parameter to"
347 " force-enable it.\n");
350 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
354 h_attr
= get_header_attr(attr
, counter
);
359 if (memcmp(&h_attr
->attr
, attr
, sizeof(*attr
))) {
360 fprintf(stderr
, "incompatible append\n");
365 if (read(fd
[nr_cpu
][counter
][thread_index
], &read_data
, sizeof(read_data
)) == -1) {
366 perror("Unable to read perf file descriptor\n");
370 if (perf_header_attr__add_id(h_attr
, read_data
.id
) < 0) {
371 pr_warning("Not enough memory to add id\n");
375 assert(fd
[nr_cpu
][counter
][thread_index
] >= 0);
376 fcntl(fd
[nr_cpu
][counter
][thread_index
], F_SETFL
, O_NONBLOCK
);
379 * First counter acts as the group leader:
381 if (group
&& group_fd
== -1)
382 group_fd
= fd
[nr_cpu
][counter
][thread_index
];
383 if (multiplex
&& multiplex_fd
== -1)
384 multiplex_fd
= fd
[nr_cpu
][counter
][thread_index
];
386 if (multiplex
&& fd
[nr_cpu
][counter
][thread_index
] != multiplex_fd
) {
388 ret
= ioctl(fd
[nr_cpu
][counter
][thread_index
], PERF_EVENT_IOC_SET_OUTPUT
, multiplex_fd
);
391 event_array
[nr_poll
].fd
= fd
[nr_cpu
][counter
][thread_index
];
392 event_array
[nr_poll
].events
= POLLIN
;
395 mmap_array
[nr_cpu
][counter
][thread_index
].counter
= counter
;
396 mmap_array
[nr_cpu
][counter
][thread_index
].prev
= 0;
397 mmap_array
[nr_cpu
][counter
][thread_index
].mask
= mmap_pages
*page_size
- 1;
398 mmap_array
[nr_cpu
][counter
][thread_index
].base
= mmap(NULL
, (mmap_pages
+1)*page_size
,
399 PROT_READ
|PROT_WRITE
, MAP_SHARED
, fd
[nr_cpu
][counter
][thread_index
], 0);
400 if (mmap_array
[nr_cpu
][counter
][thread_index
].base
== MAP_FAILED
) {
401 error("failed to mmap with %d (%s)\n", errno
, strerror(errno
));
406 if (filter
!= NULL
) {
407 ret
= ioctl(fd
[nr_cpu
][counter
][thread_index
],
408 PERF_EVENT_IOC_SET_FILTER
, filter
);
410 error("failed to set filter with %d (%s)\n", errno
,
418 static void open_counters(int cpu
)
423 for (counter
= 0; counter
< nr_counters
; counter
++)
424 create_counter(counter
, cpu
);
429 static int process_buildids(void)
431 u64 size
= lseek(output
, 0, SEEK_CUR
);
436 session
->fd
= output
;
437 return __perf_session__process_events(session
, post_processing_offset
,
438 size
- post_processing_offset
,
439 size
, &build_id__mark_dso_hit_ops
);
442 static void atexit_header(void)
445 session
->header
.data_size
+= bytes_written
;
448 perf_header__write(&session
->header
, output
, true);
452 err
= event__synthesize_build_ids(process_synthesized_event
,
455 pr_err("Couldn't synthesize build ids.\n");
459 static int __cmd_record(int argc
, const char **argv
)
466 unsigned long waking
= 0;
467 int child_ready_pipe
[2], go_pipe
[2];
468 const bool forks
= argc
> 0;
471 page_size
= sysconf(_SC_PAGE_SIZE
);
474 signal(SIGCHLD
, sig_handler
);
475 signal(SIGINT
, sig_handler
);
477 if (forks
&& (pipe(child_ready_pipe
) < 0 || pipe(go_pipe
) < 0)) {
478 perror("failed to create pipes");
482 if (!strcmp(output_name
, "-"))
484 else if (!stat(output_name
, &st
) && st
.st_size
) {
485 if (write_mode
== WRITE_FORCE
) {
486 char oldname
[PATH_MAX
];
487 snprintf(oldname
, sizeof(oldname
), "%s.old",
490 rename(output_name
, oldname
);
492 } else if (write_mode
== WRITE_APPEND
) {
493 write_mode
= WRITE_FORCE
;
496 flags
= O_CREAT
|O_RDWR
;
497 if (write_mode
== WRITE_APPEND
)
503 output
= STDOUT_FILENO
;
505 output
= open(output_name
, flags
, S_IRUSR
| S_IWUSR
);
507 perror("failed to create output file");
511 session
= perf_session__new(output_name
, O_WRONLY
,
512 write_mode
== WRITE_FORCE
);
513 if (session
== NULL
) {
514 pr_err("Not enough memory for reading perf file header\n");
519 err
= perf_header__read(session
, output
);
525 perf_header__set_feat(&session
->header
, HEADER_TRACE_INFO
);
527 for (i
= 0; i
< nr_counters
; i
++) {
528 if (attrs
[i
].sample_type
& PERF_SAMPLE_RAW
) {
529 perf_header__set_feat(&session
->header
, HEADER_TRACE_INFO
);
535 atexit(atexit_header
);
540 perror("failed to fork");
547 close(child_ready_pipe
[0]);
549 fcntl(go_pipe
[0], F_SETFD
, FD_CLOEXEC
);
552 * Do a dummy execvp to get the PLT entry resolved,
553 * so we avoid the resolver overhead on the real
556 execvp("", (char **)argv
);
559 * Tell the parent we're ready to go
561 close(child_ready_pipe
[1]);
564 * Wait until the parent tells us to go.
566 if (read(go_pipe
[0], &buf
, 1) == -1)
567 perror("unable to read pipe");
569 execvp(argv
[0], (char **)argv
);
575 if (!system_wide
&& target_tid
== -1 && target_pid
== -1)
576 all_tids
[0] = child_pid
;
578 close(child_ready_pipe
[1]);
581 * wait for child to settle
583 if (read(child_ready_pipe
[0], &buf
, 1) == -1) {
584 perror("unable to read pipe");
587 close(child_ready_pipe
[0]);
590 if ((!system_wide
&& !inherit
) || profile_cpu
!= -1) {
591 open_counters(profile_cpu
);
593 nr_cpus
= read_cpu_map();
594 for (i
= 0; i
< nr_cpus
; i
++)
595 open_counters(cpumap
[i
]);
599 err
= perf_header__write_pipe(output
);
602 } else if (file_new
) {
603 err
= perf_header__write(&session
->header
, output
, false);
608 post_processing_offset
= lseek(output
, 0, SEEK_CUR
);
611 err
= event__synthesize_attrs(&session
->header
,
612 process_synthesized_event
,
615 pr_err("Couldn't synthesize attrs.\n");
619 err
= event__synthesize_event_types(process_synthesized_event
,
622 pr_err("Couldn't synthesize event_types.\n");
626 err
= event__synthesize_tracing_data(output
, attrs
,
628 process_synthesized_event
,
631 pr_err("Couldn't record tracing data.\n");
638 err
= event__synthesize_kernel_mmap(process_synthesized_event
,
641 err
= event__synthesize_kernel_mmap(process_synthesized_event
,
644 pr_err("Couldn't record kernel reference relocation symbol.\n");
648 err
= event__synthesize_modules(process_synthesized_event
, session
);
650 pr_err("Couldn't record kernel reference relocation symbol.\n");
654 if (!system_wide
&& profile_cpu
== -1)
655 event__synthesize_thread(target_tid
, process_synthesized_event
,
658 event__synthesize_threads(process_synthesized_event
, session
);
661 struct sched_param param
;
663 param
.sched_priority
= realtime_prio
;
664 if (sched_setscheduler(0, SCHED_FIFO
, ¶m
)) {
665 pr_err("Could not set realtime priority.\n");
680 for (i
= 0; i
< nr_cpu
; i
++) {
681 for (counter
= 0; counter
< nr_counters
; counter
++) {
683 thread
< thread_num
; thread
++) {
684 if (mmap_array
[i
][counter
][thread
].base
)
685 mmap_read(&mmap_array
[i
][counter
][thread
]);
691 if (hits
== samples
) {
694 err
= poll(event_array
, nr_poll
, -1);
699 for (i
= 0; i
< nr_cpu
; i
++) {
701 counter
< nr_counters
;
706 ioctl(fd
[i
][counter
][thread
],
707 PERF_EVENT_IOC_DISABLE
);
713 fprintf(stderr
, "[ perf record: Woken up %ld times to write data ]\n", waking
);
716 * Approximate RIP event size: 24 bytes.
719 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
720 (double)bytes_written
/ 1024.0 / 1024.0,
727 static const char * const record_usage
[] = {
728 "perf record [<options>] [<command>]",
729 "perf record [<options>] -- <command> [<options>]",
733 static bool force
, append_file
;
735 static const struct option options
[] = {
736 OPT_CALLBACK('e', "event", NULL
, "event",
737 "event selector. use 'perf list' to list available events",
739 OPT_CALLBACK(0, "filter", NULL
, "filter",
740 "event filter", parse_filter
),
741 OPT_INTEGER('p', "pid", &target_pid
,
742 "record events on existing process id"),
743 OPT_INTEGER('t', "tid", &target_tid
,
744 "record events on existing thread id"),
745 OPT_INTEGER('r', "realtime", &realtime_prio
,
746 "collect data with this RT SCHED_FIFO priority"),
747 OPT_BOOLEAN('R', "raw-samples", &raw_samples
,
748 "collect raw sample records from all opened counters"),
749 OPT_BOOLEAN('a', "all-cpus", &system_wide
,
750 "system-wide collection from all CPUs"),
751 OPT_BOOLEAN('A', "append", &append_file
,
752 "append to the output file to do incremental profiling"),
753 OPT_INTEGER('C', "profile_cpu", &profile_cpu
,
754 "CPU to profile on"),
755 OPT_BOOLEAN('f', "force", &force
,
756 "overwrite existing data file (deprecated)"),
757 OPT_LONG('c', "count", &user_interval
,
758 "event period to sample"),
759 OPT_STRING('o', "output", &output_name
, "file",
761 OPT_BOOLEAN('i', "inherit", &inherit
,
762 "child tasks inherit counters"),
763 OPT_INTEGER('F', "freq", &user_freq
,
764 "profile at this frequency"),
765 OPT_INTEGER('m', "mmap-pages", &mmap_pages
,
766 "number of mmap data pages"),
767 OPT_BOOLEAN('g', "call-graph", &call_graph
,
768 "do call-graph (stack chain/backtrace) recording"),
769 OPT_INCR('v', "verbose", &verbose
,
770 "be more verbose (show counter open errors, etc)"),
771 OPT_BOOLEAN('s', "stat", &inherit_stat
,
772 "per thread counts"),
773 OPT_BOOLEAN('d', "data", &sample_address
,
775 OPT_BOOLEAN('n', "no-samples", &no_samples
,
777 OPT_BOOLEAN('M', "multiplex", &multiplex
,
778 "multiplex counter output in a single channel"),
782 int cmd_record(int argc
, const char **argv
, const char *prefix __used
)
786 argc
= parse_options(argc
, argv
, options
, record_usage
,
787 PARSE_OPT_STOP_AT_NON_OPTION
);
788 if (!argc
&& target_pid
== -1 && target_tid
== -1 &&
789 !system_wide
&& profile_cpu
== -1)
790 usage_with_options(record_usage
, options
);
792 if (force
&& append_file
) {
793 fprintf(stderr
, "Can't overwrite and append at the same time."
794 " You need to choose between -f and -A");
795 usage_with_options(record_usage
, options
);
796 } else if (append_file
) {
797 write_mode
= WRITE_APPEND
;
799 write_mode
= WRITE_FORCE
;
806 attrs
[0].type
= PERF_TYPE_HARDWARE
;
807 attrs
[0].config
= PERF_COUNT_HW_CPU_CYCLES
;
810 if (target_pid
!= -1) {
811 target_tid
= target_pid
;
812 thread_num
= find_all_tid(target_pid
, &all_tids
);
813 if (thread_num
<= 0) {
814 fprintf(stderr
, "Can't find all threads of pid %d\n",
816 usage_with_options(record_usage
, options
);
819 all_tids
=malloc(sizeof(pid_t
));
823 all_tids
[0] = target_tid
;
827 for (i
= 0; i
< MAX_NR_CPUS
; i
++) {
828 for (j
= 0; j
< MAX_COUNTERS
; j
++) {
829 fd
[i
][j
] = malloc(sizeof(int)*thread_num
);
830 mmap_array
[i
][j
] = zalloc(
831 sizeof(struct mmap_data
)*thread_num
);
832 if (!fd
[i
][j
] || !mmap_array
[i
][j
])
836 event_array
= malloc(
837 sizeof(struct pollfd
)*MAX_NR_CPUS
*MAX_COUNTERS
*thread_num
);
841 if (user_interval
!= UINT_MAX
)
842 default_interval
= user_interval
;
843 if (user_freq
!= UINT_MAX
)
847 * User specified count overrides default frequency.
849 if (default_interval
)
852 default_interval
= freq
;
854 fprintf(stderr
, "frequency and count are zero, aborting\n");
858 return __cmd_record(argc
, argv
);