tools/perf/builtin-record.c - kernel/msm-4.9 - Gitiles

 /*
  * 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.
  */
 #define _FILE_OFFSET_BITS 64

 #include "builtin.h"

 #include "perf.h"

 #include "util/build-id.h"
 #include "util/util.h"
 #include "util/parse-options.h"
 #include "util/parse-events.h"

 #include "util/header.h"
 #include "util/event.h"
 #include "util/evlist.h"
 #include "util/evsel.h"
 #include "util/debug.h"
 #include "util/session.h"
 #include "util/symbol.h"
 #include "util/cpumap.h"
 #include "util/thread_map.h"

 #include <unistd.h>
 #include <sched.h>
 #include <sys/mman.h>

 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))

 enum write_mode_t {
 	WRITE_FORCE,
 	WRITE_APPEND
 };

 static u64			user_interval			= ULLONG_MAX;
 static u64			default_interval		=      0;

 static unsigned int		page_size;
 static unsigned int		mmap_pages			= UINT_MAX;
 static unsigned int		user_freq 			= UINT_MAX;
 static int			freq				=   1000;
 static int			output;
 static int			pipe_output			=      0;
 static const char		*output_name			= NULL;
 static int			group				=      0;
 static int			realtime_prio			=      0;
 static bool			nodelay				=  false;
 static bool			raw_samples			=  false;
 static bool			sample_id_all_avail		=   true;
 static bool			system_wide			=  false;
 static pid_t			target_pid			=     -1;
 static pid_t			target_tid			=     -1;
 static pid_t			child_pid			=     -1;
 static bool			no_inherit			=  false;
 static enum write_mode_t	write_mode			= WRITE_FORCE;
 static bool			call_graph			=  false;
 static bool			inherit_stat			=  false;
 static bool			no_samples			=  false;
 static bool			sample_address			=  false;
 static bool			sample_time			=  false;
 static bool			no_buildid			=  false;
 static bool			no_buildid_cache		=  false;
 static struct perf_evlist	*evsel_list;

 static long			samples				=      0;
 static u64			bytes_written			=      0;

 static int			file_new			=      1;
 static off_t			post_processing_offset;

 static struct perf_session	*session;
 static const char		*cpu_list;

 static void advance_output(size_t size)
 {
 	bytes_written += size;
 }

 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 int process_synthesized_event(union perf_event *event,
 				     struct perf_sample *sample __used,
 				     struct perf_session *self __used)
 {
 	write_output(event, event->header.size);
 	return 0;
 }

 static void mmap_read(struct perf_mmap *md)
 {
 	unsigned int head = perf_mmap__read_head(md);
 	unsigned int old = md->prev;
 	unsigned char *data = md->base + page_size;
 	unsigned long size;
 	void *buf;

 	if (old == head)
 		return;

 	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;
 	perf_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 (child_pid > 0)
 		kill(child_pid, SIGTERM);

 	if (signr == -1 || signr == SIGUSR1)
 		return;

 	signal(signr, SIG_DFL);
 	kill(getpid(), signr);
 }

 static void config_attr(struct perf_evsel *evsel, struct perf_evlist *evlist)
 {
 	struct perf_event_attr *attr = &evsel->attr;
 	int track = !evsel->idx; /* only the first counter needs these */

 	attr->inherit		= !no_inherit;
 	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 (evlist->nr_entries > 1)
 		attr->sample_type |= PERF_SAMPLE_ID;

 	/*
 	 * We default some events to a 1 default interval. But keep
 	 * it a weak assumption overridable by the user.
 	 */
 	if (!attr->sample_period || (user_freq != UINT_MAX &&
 				     user_interval != ULLONG_MAX)) {
 		if (freq) {
 			attr->sample_type	|= PERF_SAMPLE_PERIOD;
 			attr->freq		= 1;
 			attr->sample_freq	= freq;
 		} else {
 			attr->sample_period = default_interval;
 		}
 	}

 	if (no_samples)
 		attr->sample_freq = 0;

 	if (inherit_stat)
 		attr->inherit_stat = 1;

 	if (sample_address) {
 		attr->sample_type	|= PERF_SAMPLE_ADDR;
 		attr->mmap_data = track;
 	}

 	if (call_graph)
 		attr->sample_type	|= PERF_SAMPLE_CALLCHAIN;

 	if (system_wide)
 		attr->sample_type	|= PERF_SAMPLE_CPU;

 	if (sample_id_all_avail &&
 	    (sample_time || system_wide || !no_inherit || cpu_list))
 		attr->sample_type	|= PERF_SAMPLE_TIME;

 	if (raw_samples) {
 		attr->sample_type	|= PERF_SAMPLE_TIME;
 		attr->sample_type	|= PERF_SAMPLE_RAW;
 		attr->sample_type	|= PERF_SAMPLE_CPU;
 	}

 	if (nodelay) {
 		attr->watermark = 0;
 		attr->wakeup_events = 1;
 	}

 	attr->mmap		= track;
 	attr->comm		= track;

 	if (target_pid == -1 && target_tid == -1 && !system_wide) {
 		attr->disabled = 1;
 		attr->enable_on_exec = 1;
 	}
 }

 static bool perf_evlist__equal(struct perf_evlist *evlist,
 			       struct perf_evlist *other)
 {
 	struct perf_evsel *pos, *pair;

 	if (evlist->nr_entries != other->nr_entries)
 		return false;

 	pair = list_entry(other->entries.next, struct perf_evsel, node);

 	list_for_each_entry(pos, &evlist->entries, node) {
 		if (memcmp(&pos->attr, &pair->attr, sizeof(pos->attr) != 0))
 			return false;
 		pair = list_entry(pair->node.next, struct perf_evsel, node);
 	}

 	return true;
 }

 static void open_counters(struct perf_evlist *evlist)
 {
 	struct perf_evsel *pos;

 	if (evlist->cpus->map[0] < 0)
 		no_inherit = true;

 	list_for_each_entry(pos, &evlist->entries, node) {
 		struct perf_event_attr *attr = &pos->attr;
 		/*
 		 * Check if parse_single_tracepoint_event has already asked for
 		 * PERF_SAMPLE_TIME.
 		 *
 		 * XXX this is kludgy but short term fix for problems introduced by
 		 * eac23d1c that broke 'perf script' by having different sample_types
 		 * when using multiple tracepoint events when we use a perf binary
 		 * that tries to use sample_id_all on an older kernel.
 		 *
 		 * We need to move counter creation to perf_session, support
 		 * different sample_types, etc.
 		 */
 		bool time_needed = attr->sample_type & PERF_SAMPLE_TIME;

 		config_attr(pos, evlist);
 retry_sample_id:
 		attr->sample_id_all = sample_id_all_avail ? 1 : 0;
 try_again:
 		if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group) < 0) {
 			int err = errno;

 			if (err == EPERM || err == EACCES) {
 				ui__warning_paranoid();
 				exit(EXIT_FAILURE);
 			} else if (err ==  ENODEV && cpu_list) {
 				die("No such device - did you specify"
 					" an out-of-range profile CPU?\n");
 			} else if (err == EINVAL && sample_id_all_avail) {
 				/*
 				 * Old kernel, no attr->sample_id_type_all field
 				 */
 				sample_id_all_avail = false;
 				if (!sample_time && !raw_samples && !time_needed)
 					attr->sample_type &= ~PERF_SAMPLE_TIME;

 				goto retry_sample_id;
 			}

 			/*
 			 * 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)
 					ui__warning("The cycles event is not supported, "
 						    "trying to fall back to cpu-clock-ticks\n");
 				attr->type = PERF_TYPE_SOFTWARE;
 				attr->config = PERF_COUNT_SW_CPU_CLOCK;
 				goto try_again;
 			}

 			if (err == ENOENT) {
 				ui__warning("The %s event is not supported.\n",
 					    event_name(pos));
 				exit(EXIT_FAILURE);
 			}

 			printf("\n");
 			error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
 			      err, strerror(err));

 #if defined(__i386__) || defined(__x86_64__)
 			if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
 				die("No hardware sampling interrupt available."
 				    " No APIC? If so then you can boot the kernel"
 				    " with the \"lapic\" boot parameter to"
 				    " force-enable it.\n");
 #endif

 			die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
 		}
 	}

 	if (perf_evlist__set_filters(evlist)) {
 		error("failed to set filter with %d (%s)\n", errno,
 			strerror(errno));
 		exit(-1);
 	}

 	if (perf_evlist__mmap(evlist, mmap_pages, false) < 0)
 		die("failed to mmap with %d (%s)\n", errno, strerror(errno));

 	if (file_new)
 		session->evlist = evlist;
 	else {
 		if (!perf_evlist__equal(session->evlist, evlist)) {
 			fprintf(stderr, "incompatible append\n");
 			exit(-1);
 		}
  	}

 	perf_session__update_sample_type(session);
 }

 static int process_buildids(void)
 {
 	u64 size = lseek(output, 0, SEEK_CUR);

 	if (size == 0)
 		return 0;

 	session->fd = output;
 	return __perf_session__process_events(session, post_processing_offset,
 					      size - post_processing_offset,
 					      size, &build_id__mark_dso_hit_ops);
 }

 static void atexit_header(void)
 {
 	if (!pipe_output) {
 		session->header.data_size += bytes_written;

 		if (!no_buildid)
 			process_buildids();
 		perf_session__write_header(session, evsel_list, output, true);
 		perf_session__delete(session);
 		perf_evlist__delete(evsel_list);
 		symbol__exit();
 	}
 }

 static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
 {
 	int err;
 	struct perf_session *psession = data;

 	if (machine__is_host(machine))
 		return;

 	/*
 	 *As for guest kernel when processing subcommand record&report,
 	 *we arrange module mmap prior to guest kernel mmap and trigger
 	 *a preload dso because default guest module symbols are loaded
 	 *from guest kallsyms instead of /lib/modules/XXX/XXX. This
 	 *method is used to avoid symbol missing when the first addr is
 	 *in module instead of in guest kernel.
 	 */
 	err = perf_event__synthesize_modules(process_synthesized_event,
 					     psession, machine);
 	if (err < 0)
 		pr_err("Couldn't record guest kernel [%d]'s reference"
 		       " relocation symbol.\n", machine->pid);

 	/*
 	 * We use _stext for guest kernel because guest kernel's /proc/kallsyms
 	 * have no _text sometimes.
 	 */
 	err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
 						 psession, machine, "_text");
 	if (err < 0)
 		err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
 							 psession, machine,
 							 "_stext");
 	if (err < 0)
 		pr_err("Couldn't record guest kernel [%d]'s reference"
 		       " relocation symbol.\n", machine->pid);
 }

 static struct perf_event_header finished_round_event = {
 	.size = sizeof(struct perf_event_header),
 	.type = PERF_RECORD_FINISHED_ROUND,
 };

 static void mmap_read_all(void)
 {
 	int i;

 	for (i = 0; i < evsel_list->nr_mmaps; i++) {
 		if (evsel_list->mmap[i].base)
 			mmap_read(&evsel_list->mmap[i]);
 	}

 	if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
 		write_output(&finished_round_event, sizeof(finished_round_event));
 }

 static int __cmd_record(int argc, const char **argv)
 {
 	int i;
 	struct stat st;
 	int flags;
 	int err;
 	unsigned long waking = 0;
 	int child_ready_pipe[2], go_pipe[2];
 	const bool forks = argc > 0;
 	char buf;
 	struct machine *machine;

 	page_size = sysconf(_SC_PAGE_SIZE);

 	atexit(sig_atexit);
 	signal(SIGCHLD, sig_handler);
 	signal(SIGINT, sig_handler);
 	signal(SIGUSR1, sig_handler);

 	if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
 		perror("failed to create pipes");
 		exit(-1);
 	}

 	if (!output_name) {
 		if (!fstat(STDOUT_FILENO, &st) && S_ISFIFO(st.st_mode))
 			pipe_output = 1;
 		else
 			output_name = "perf.data";
 	}
 	if (output_name) {
 		if (!strcmp(output_name, "-"))
 			pipe_output = 1;
 		else if (!stat(output_name, &st) && st.st_size) {
 			if (write_mode == WRITE_FORCE) {
 				char oldname[PATH_MAX];
 				snprintf(oldname, sizeof(oldname), "%s.old",
 					 output_name);
 				unlink(oldname);
 				rename(output_name, oldname);
 			}
 		} else if (write_mode == WRITE_APPEND) {
 			write_mode = WRITE_FORCE;
 		}
 	}

 	flags = O_CREAT|O_RDWR;
 	if (write_mode == WRITE_APPEND)
 		file_new = 0;
 	else
 		flags |= O_TRUNC;

 	if (pipe_output)
 		output = STDOUT_FILENO;
 	else
 		output = open(output_name, flags, S_IRUSR | S_IWUSR);
 	if (output < 0) {
 		perror("failed to create output file");
 		exit(-1);
 	}

 	session = perf_session__new(output_name, O_WRONLY,
 				    write_mode == WRITE_FORCE, false, NULL);
 	if (session == NULL) {
 		pr_err("Not enough memory for reading perf file header\n");
 		return -1;
 	}

 	if (!no_buildid)
 		perf_header__set_feat(&session->header, HEADER_BUILD_ID);

 	if (!file_new) {
 		err = perf_session__read_header(session, output);
 		if (err < 0)
 			goto out_delete_session;
 	}

 	if (have_tracepoints(&evsel_list->entries))
 		perf_header__set_feat(&session->header, HEADER_TRACE_INFO);

 	/* 512 kiB: default amount of unprivileged mlocked memory */
 	if (mmap_pages == UINT_MAX)
 		mmap_pages = (512 * 1024) / page_size;

 	if (forks) {
 		child_pid = fork();
 		if (child_pid < 0) {
 			perror("failed to fork");
 			exit(-1);
 		}

 		if (!child_pid) {
 			if (pipe_output)
 				dup2(2, 1);
 			close(child_ready_pipe[0]);
 			close(go_pipe[1]);
 			fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);

 			/*
 			 * Do a dummy execvp to get the PLT entry resolved,
 			 * so we avoid the resolver overhead on the real
 			 * execvp call.
 			 */
 			execvp("", (char **)argv);

 			/*
 			 * Tell the parent we're ready to go
 			 */
 			close(child_ready_pipe[1]);

 			/*
 			 * Wait until the parent tells us to go.
 			 */
 			if (read(go_pipe[0], &buf, 1) == -1)
 				perror("unable to read pipe");

 			execvp(argv[0], (char **)argv);

 			perror(argv[0]);
 			kill(getppid(), SIGUSR1);
 			exit(-1);
 		}

 		if (!system_wide && target_tid == -1 && target_pid == -1)
 			evsel_list->threads->map[0] = child_pid;

 		close(child_ready_pipe[1]);
 		close(go_pipe[0]);
 		/*
 		 * wait for child to settle
 		 */
 		if (read(child_ready_pipe[0], &buf, 1) == -1) {
 			perror("unable to read pipe");
 			exit(-1);
 		}
 		close(child_ready_pipe[0]);
 	}

 	open_counters(evsel_list);

 	/*
 	 * perf_session__delete(session) will be called at atexit_header()
 	 */
 	atexit(atexit_header);

 	if (pipe_output) {
 		err = perf_header__write_pipe(output);
 		if (err < 0)
 			return err;
 	} else if (file_new) {
 		err = perf_session__write_header(session, evsel_list,
 						 output, false);
 		if (err < 0)
 			return err;
 	}

 	post_processing_offset = lseek(output, 0, SEEK_CUR);

 	if (pipe_output) {
 		err = perf_session__synthesize_attrs(session,
 						     process_synthesized_event);
 		if (err < 0) {
 			pr_err("Couldn't synthesize attrs.\n");
 			return err;
 		}

 		err = perf_event__synthesize_event_types(process_synthesized_event,
 							 session);
 		if (err < 0) {
 			pr_err("Couldn't synthesize event_types.\n");
 			return err;
 		}

 		if (have_tracepoints(&evsel_list->entries)) {
 			/*
 			 * FIXME err <= 0 here actually means that
 			 * there were no tracepoints so its not really
 			 * an error, just that we don't need to
 			 * synthesize anything.  We really have to
 			 * return this more properly and also
 			 * propagate errors that now are calling die()
 			 */
 			err = perf_event__synthesize_tracing_data(output, evsel_list,
 								  process_synthesized_event,
 								  session);
 			if (err <= 0) {
 				pr_err("Couldn't record tracing data.\n");
 				return err;
 			}
 			advance_output(err);
 		}
 	}

 	machine = perf_session__find_host_machine(session);
 	if (!machine) {
 		pr_err("Couldn't find native kernel information.\n");
 		return -1;
 	}

 	err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
 						 session, machine, "_text");
 	if (err < 0)
 		err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
 							 session, machine, "_stext");
 	if (err < 0)
 		pr_err("Couldn't record kernel reference relocation symbol\n"
 		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 		       "Check /proc/kallsyms permission or run as root.\n");

 	err = perf_event__synthesize_modules(process_synthesized_event,
 					     session, machine);
 	if (err < 0)
 		pr_err("Couldn't record kernel module information.\n"
 		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 		       "Check /proc/modules permission or run as root.\n");

 	if (perf_guest)
 		perf_session__process_machines(session,
 					       perf_event__synthesize_guest_os);

 	if (!system_wide)
 		perf_event__synthesize_thread_map(evsel_list->threads,
 						  process_synthesized_event,
 						  session);
 	else
 		perf_event__synthesize_threads(process_synthesized_event,
 					       session);

 	if (realtime_prio) {
 		struct sched_param param;

 		param.sched_priority = realtime_prio;
 		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
 			pr_err("Could not set realtime priority.\n");
 			exit(-1);
 		}
 	}

 	/*
 	 * Let the child rip
 	 */
 	if (forks)
 		close(go_pipe[1]);

 	for (;;) {
 		int hits = samples;
 		int thread;

 		mmap_read_all();

 		if (hits == samples) {
 			if (done)
 				break;
 			err = poll(evsel_list->pollfd, evsel_list->nr_fds, -1);
 			waking++;
 		}

 		if (done) {
 			for (i = 0; i < evsel_list->cpus->nr; i++) {
 				struct perf_evsel *pos;

 				list_for_each_entry(pos, &evsel_list->entries, node) {
 					for (thread = 0;
 						thread < evsel_list->threads->nr;
 						thread++)
 						ioctl(FD(pos, i, thread),
 							PERF_EVENT_IOC_DISABLE);
 				}
 			}
 		}
 	}

 	if (quiet || signr == SIGUSR1)
 		return 0;

 	fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);

 	/*
 	 * Approximate RIP event size: 24 bytes.
 	 */
 	fprintf(stderr,
 		"[ perf record: Captured and wrote %.3f MB %s (~%" PRIu64 " samples) ]\n",
 		(double)bytes_written / 1024.0 / 1024.0,
 		output_name,
 		bytes_written / 24);

 	return 0;

 out_delete_session:
 	perf_session__delete(session);
 	return err;
 }

 static const char * const record_usage[] = {
 	"perf record [<options>] [<command>]",
 	"perf record [<options>] -- <command> [<options>]",
 	NULL
 };

 static bool force, append_file;

 const struct option record_options[] = {
 	OPT_CALLBACK('e', "event", &evsel_list, "event",
 		     "event selector. use 'perf list' to list available events",
 		     parse_events),
 	OPT_CALLBACK(0, "filter", &evsel_list, "filter",
 		     "event filter", parse_filter),
 	OPT_INTEGER('p', "pid", &target_pid,
 		    "record events on existing process id"),
 	OPT_INTEGER('t', "tid", &target_tid,
 		    "record events on existing thread id"),
 	OPT_INTEGER('r', "realtime", &realtime_prio,
 		    "collect data with this RT SCHED_FIFO priority"),
 	OPT_BOOLEAN('D', "no-delay", &nodelay,
 		    "collect data without buffering"),
 	OPT_BOOLEAN('R', "raw-samples", &raw_samples,
 		    "collect raw sample records from all opened counters"),
 	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_STRING('C', "cpu", &cpu_list, "cpu",
 		    "list of cpus to monitor"),
 	OPT_BOOLEAN('f', "force", &force,
 			"overwrite existing data file (deprecated)"),
 	OPT_U64('c', "count", &user_interval, "event period to sample"),
 	OPT_STRING('o', "output", &output_name, "file",
 		    "output file name"),
 	OPT_BOOLEAN('i', "no-inherit", &no_inherit,
 		    "child tasks do not inherit counters"),
 	OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
 	OPT_UINTEGER('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_INCR('v', "verbose", &verbose,
 		    "be more verbose (show counter open errors, etc)"),
 	OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
 	OPT_BOOLEAN('s', "stat", &inherit_stat,
 		    "per thread counts"),
 	OPT_BOOLEAN('d', "data", &sample_address,
 		    "Sample addresses"),
 	OPT_BOOLEAN('T', "timestamp", &sample_time, "Sample timestamps"),
 	OPT_BOOLEAN('n', "no-samples", &no_samples,
 		    "don't sample"),
 	OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid_cache,
 		    "do not update the buildid cache"),
 	OPT_BOOLEAN('B', "no-buildid", &no_buildid,
 		    "do not collect buildids in perf.data"),
 	OPT_CALLBACK('G', "cgroup", &evsel_list, "name",
 		     "monitor event in cgroup name only",
 		     parse_cgroups),
 	OPT_END()
 };

 int cmd_record(int argc, const char **argv, const char *prefix __used)
 {
 	int err = -ENOMEM;
 	struct perf_evsel *pos;

 	evsel_list = perf_evlist__new(NULL, NULL);
 	if (evsel_list == NULL)
 		return -ENOMEM;

 	argc = parse_options(argc, argv, record_options, record_usage,
 			    PARSE_OPT_STOP_AT_NON_OPTION);
 	if (!argc && target_pid == -1 && target_tid == -1 &&
 		!system_wide && !cpu_list)
 		usage_with_options(record_usage, record_options);

 	if (force && append_file) {
 		fprintf(stderr, "Can't overwrite and append at the same time."
 				" You need to choose between -f and -A");
 		usage_with_options(record_usage, record_options);
 	} else if (append_file) {
 		write_mode = WRITE_APPEND;
 	} else {
 		write_mode = WRITE_FORCE;
 	}

 	if (nr_cgroups && !system_wide) {
 		fprintf(stderr, "cgroup monitoring only available in"
 			" system-wide mode\n");
 		usage_with_options(record_usage, record_options);
 	}

 	symbol__init();

 	if (no_buildid_cache || no_buildid)
 		disable_buildid_cache();

 	if (evsel_list->nr_entries == 0 &&
 	    perf_evlist__add_default(evsel_list) < 0) {
 		pr_err("Not enough memory for event selector list\n");
 		goto out_symbol_exit;
 	}

 	if (target_pid != -1)
 		target_tid = target_pid;

 	if (perf_evlist__create_maps(evsel_list, target_pid,
 				     target_tid, cpu_list) < 0)
 		usage_with_options(record_usage, record_options);

 	list_for_each_entry(pos, &evsel_list->entries, node) {
 		if (perf_evsel__alloc_fd(pos, evsel_list->cpus->nr,
 					 evsel_list->threads->nr) < 0)
 			goto out_free_fd;
 		if (perf_header__push_event(pos->attr.config, event_name(pos)))
 			goto out_free_fd;
 	}

 	if (perf_evlist__alloc_pollfd(evsel_list) < 0)
 		goto out_free_fd;

 	if (user_interval != ULLONG_MAX)
 		default_interval = user_interval;
 	if (user_freq != UINT_MAX)
 		freq = user_freq;

 	/*
 	 * User specified count overrides default frequency.
 	 */
 	if (default_interval)
 		freq = 0;
 	else if (freq) {
 		default_interval = freq;
 	} else {
 		fprintf(stderr, "frequency and count are zero, aborting\n");
 		err = -EINVAL;
 		goto out_free_fd;
 	}

 	err = __cmd_record(argc, argv);
 out_free_fd:
 	perf_evlist__delete_maps(evsel_list);
 out_symbol_exit:
 	symbol__exit();
 	return err;
 }
	/*
	* 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.
	*/
	#define _FILE_OFFSET_BITS 64

	#include "builtin.h"

	#include "perf.h"

	#include "util/build-id.h"
	#include "util/util.h"
	#include "util/parse-options.h"
	#include "util/parse-events.h"

	#include "util/header.h"
	#include "util/event.h"
	#include "util/evlist.h"
	#include "util/evsel.h"
	#include "util/debug.h"
	#include "util/session.h"
	#include "util/symbol.h"
	#include "util/cpumap.h"
	#include "util/thread_map.h"

	#include <unistd.h>
	#include <sched.h>
	#include <sys/mman.h>

	#define FD(e, x, y) ((int )xyarray__entry(e->fd, x, y))

	enum write_mode_t {
	WRITE_FORCE,
	WRITE_APPEND
	};

	static u64 user_interval = ULLONG_MAX;
	static u64 default_interval = 0;

	static unsigned int page_size;
	static unsigned int mmap_pages = UINT_MAX;
	static unsigned int user_freq = UINT_MAX;
	static int freq = 1000;
	static int output;
	static int pipe_output = 0;
	static const char *output_name = NULL;
	static int group = 0;
	static int realtime_prio = 0;
	static bool nodelay = false;
	static bool raw_samples = false;
	static bool sample_id_all_avail = true;
	static bool system_wide = false;
	static pid_t target_pid = -1;
	static pid_t target_tid = -1;
	static pid_t child_pid = -1;
	static bool no_inherit = false;
	static enum write_mode_t write_mode = WRITE_FORCE;
	static bool call_graph = false;
	static bool inherit_stat = false;
	static bool no_samples = false;
	static bool sample_address = false;
	static bool sample_time = false;
	static bool no_buildid = false;
	static bool no_buildid_cache = false;
	static struct perf_evlist *evsel_list;

	static long samples = 0;
	static u64 bytes_written = 0;

	static int file_new = 1;
	static off_t post_processing_offset;

	static struct perf_session *session;
	static const char *cpu_list;

	static void advance_output(size_t size)
	{
	bytes_written += size;
	}

	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 int process_synthesized_event(union perf_event *event,
	struct perf_sample *sample __used,
	struct perf_session *self __used)
	{
	write_output(event, event->header.size);
	return 0;
	}

	static void mmap_read(struct perf_mmap *md)
	{
	unsigned int head = perf_mmap__read_head(md);
	unsigned int old = md->prev;
	unsigned char *data = md->base + page_size;
	unsigned long size;
	void *buf;

	if (old == head)
	return;

	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;
	perf_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 (child_pid > 0)
	kill(child_pid, SIGTERM);

	if (signr == -1 \|\| signr == SIGUSR1)
	return;

	signal(signr, SIG_DFL);
	kill(getpid(), signr);
	}

	static void config_attr(struct perf_evsel evsel, struct perf_evlist evlist)
	{
	struct perf_event_attr *attr = &evsel->attr;
	int track = !evsel->idx; /* only the first counter needs these */

	attr->inherit = !no_inherit;
	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 (evlist->nr_entries > 1)
	attr->sample_type \|= PERF_SAMPLE_ID;

	/*
	* We default some events to a 1 default interval. But keep
	* it a weak assumption overridable by the user.
	*/
	if (!attr->sample_period \|\| (user_freq != UINT_MAX &&
	user_interval != ULLONG_MAX)) {
	if (freq) {
	attr->sample_type \|= PERF_SAMPLE_PERIOD;
	attr->freq = 1;
	attr->sample_freq = freq;
	} else {
	attr->sample_period = default_interval;
	}
	}

	if (no_samples)
	attr->sample_freq = 0;

	if (inherit_stat)
	attr->inherit_stat = 1;

	if (sample_address) {
	attr->sample_type \|= PERF_SAMPLE_ADDR;
	attr->mmap_data = track;
	}

	if (call_graph)
	attr->sample_type \|= PERF_SAMPLE_CALLCHAIN;

	if (system_wide)
	attr->sample_type \|= PERF_SAMPLE_CPU;

	if (sample_id_all_avail &&
	(sample_time \|\| system_wide \|\| !no_inherit \|\| cpu_list))
	attr->sample_type \|= PERF_SAMPLE_TIME;

	if (raw_samples) {
	attr->sample_type \|= PERF_SAMPLE_TIME;
	attr->sample_type \|= PERF_SAMPLE_RAW;
	attr->sample_type \|= PERF_SAMPLE_CPU;
	}

	if (nodelay) {
	attr->watermark = 0;
	attr->wakeup_events = 1;
	}

	attr->mmap = track;
	attr->comm = track;

	if (target_pid == -1 && target_tid == -1 && !system_wide) {
	attr->disabled = 1;
	attr->enable_on_exec = 1;
	}
	}

	static bool perf_evlist__equal(struct perf_evlist *evlist,
	struct perf_evlist *other)
	{
	struct perf_evsel pos, pair;

	if (evlist->nr_entries != other->nr_entries)
	return false;

	pair = list_entry(other->entries.next, struct perf_evsel, node);

	list_for_each_entry(pos, &evlist->entries, node) {
	if (memcmp(&pos->attr, &pair->attr, sizeof(pos->attr) != 0))
	return false;
	pair = list_entry(pair->node.next, struct perf_evsel, node);
	}

	return true;
	}

	static void open_counters(struct perf_evlist *evlist)
	{
	struct perf_evsel *pos;

	if (evlist->cpus->map[0] < 0)
	no_inherit = true;

	list_for_each_entry(pos, &evlist->entries, node) {
	struct perf_event_attr *attr = &pos->attr;
	/*
	* Check if parse_single_tracepoint_event has already asked for
	* PERF_SAMPLE_TIME.
	*
	* XXX this is kludgy but short term fix for problems introduced by
	* eac23d1c that broke 'perf script' by having different sample_types
	* when using multiple tracepoint events when we use a perf binary
	* that tries to use sample_id_all on an older kernel.
	*
	* We need to move counter creation to perf_session, support
	* different sample_types, etc.
	*/
	bool time_needed = attr->sample_type & PERF_SAMPLE_TIME;

	config_attr(pos, evlist);
	retry_sample_id:
	attr->sample_id_all = sample_id_all_avail ? 1 : 0;
	try_again:
	if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group) < 0) {
	int err = errno;

	if (err == EPERM \|\| err == EACCES) {
	ui__warning_paranoid();
	exit(EXIT_FAILURE);
	} else if (err == ENODEV && cpu_list) {
	die("No such device - did you specify"
	" an out-of-range profile CPU?\n");
	} else if (err == EINVAL && sample_id_all_avail) {
	/*
	* Old kernel, no attr->sample_id_type_all field
	*/
	sample_id_all_avail = false;
	if (!sample_time && !raw_samples && !time_needed)
	attr->sample_type &= ~PERF_SAMPLE_TIME;

	goto retry_sample_id;
	}

	/*
	* 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)
	ui__warning("The cycles event is not supported, "
	"trying to fall back to cpu-clock-ticks\n");
	attr->type = PERF_TYPE_SOFTWARE;
	attr->config = PERF_COUNT_SW_CPU_CLOCK;
	goto try_again;
	}

	if (err == ENOENT) {
	ui__warning("The %s event is not supported.\n",
	event_name(pos));
	exit(EXIT_FAILURE);
	}

	printf("\n");
	error("sys_perf_event_open() syscall returned with %d (%s). /bin/dmesg may provide additional information.\n",
	err, strerror(err));

	#if defined(__i386__) \|\| defined(__x86_64__)
	if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
	die("No hardware sampling interrupt available."
	" No APIC? If so then you can boot the kernel"
	" with the \"lapic\" boot parameter to"
	" force-enable it.\n");
	#endif

	die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
	}
	}

	if (perf_evlist__set_filters(evlist)) {
	error("failed to set filter with %d (%s)\n", errno,
	strerror(errno));
	exit(-1);
	}

	if (perf_evlist__mmap(evlist, mmap_pages, false) < 0)
	die("failed to mmap with %d (%s)\n", errno, strerror(errno));

	if (file_new)
	session->evlist = evlist;
	else {
	if (!perf_evlist__equal(session->evlist, evlist)) {
	fprintf(stderr, "incompatible append\n");
	exit(-1);
	}
	}

	perf_session__update_sample_type(session);
	}

	static int process_buildids(void)
	{
	u64 size = lseek(output, 0, SEEK_CUR);

	if (size == 0)
	return 0;

	session->fd = output;
	return __perf_session__process_events(session, post_processing_offset,
	size - post_processing_offset,
	size, &build_id__mark_dso_hit_ops);
	}

	static void atexit_header(void)
	{
	if (!pipe_output) {
	session->header.data_size += bytes_written;

	if (!no_buildid)
	process_buildids();
	perf_session__write_header(session, evsel_list, output, true);
	perf_session__delete(session);
	perf_evlist__delete(evsel_list);
	symbol__exit();
	}
	}

	static void perf_event__synthesize_guest_os(struct machine machine, void data)
	{
	int err;
	struct perf_session *psession = data;

	if (machine__is_host(machine))
	return;

	/*
	*As for guest kernel when processing subcommand record&report,
	*we arrange module mmap prior to guest kernel mmap and trigger
	*a preload dso because default guest module symbols are loaded
	*from guest kallsyms instead of /lib/modules/XXX/XXX. This
	*method is used to avoid symbol missing when the first addr is
	*in module instead of in guest kernel.
	*/
	err = perf_event__synthesize_modules(process_synthesized_event,
	psession, machine);
	if (err < 0)
	pr_err("Couldn't record guest kernel [%d]'s reference"
	" relocation symbol.\n", machine->pid);

	/*
	* We use _stext for guest kernel because guest kernel's /proc/kallsyms
	* have no _text sometimes.
	*/
	err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
	psession, machine, "_text");
	if (err < 0)
	err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
	psession, machine,
	"_stext");
	if (err < 0)
	pr_err("Couldn't record guest kernel [%d]'s reference"
	" relocation symbol.\n", machine->pid);
	}

	static struct perf_event_header finished_round_event = {
	.size = sizeof(struct perf_event_header),
	.type = PERF_RECORD_FINISHED_ROUND,
	};

	static void mmap_read_all(void)
	{
	int i;

	for (i = 0; i < evsel_list->nr_mmaps; i++) {
	if (evsel_list->mmap[i].base)
	mmap_read(&evsel_list->mmap[i]);
	}

	if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
	write_output(&finished_round_event, sizeof(finished_round_event));
	}

	static int __cmd_record(int argc, const char **argv)
	{
	int i;
	struct stat st;
	int flags;
	int err;
	unsigned long waking = 0;
	int child_ready_pipe[2], go_pipe[2];
	const bool forks = argc > 0;
	char buf;
	struct machine *machine;

	page_size = sysconf(_SC_PAGE_SIZE);

	atexit(sig_atexit);
	signal(SIGCHLD, sig_handler);
	signal(SIGINT, sig_handler);
	signal(SIGUSR1, sig_handler);

	if (forks && (pipe(child_ready_pipe) < 0 \|\| pipe(go_pipe) < 0)) {
	perror("failed to create pipes");
	exit(-1);
	}

	if (!output_name) {
	if (!fstat(STDOUT_FILENO, &st) && S_ISFIFO(st.st_mode))
	pipe_output = 1;
	else
	output_name = "perf.data";
	}
	if (output_name) {
	if (!strcmp(output_name, "-"))
	pipe_output = 1;
	else if (!stat(output_name, &st) && st.st_size) {
	if (write_mode == WRITE_FORCE) {
	char oldname[PATH_MAX];
	snprintf(oldname, sizeof(oldname), "%s.old",
	output_name);
	unlink(oldname);
	rename(output_name, oldname);
	}
	} else if (write_mode == WRITE_APPEND) {
	write_mode = WRITE_FORCE;
	}
	}

	flags = O_CREAT\|O_RDWR;
	if (write_mode == WRITE_APPEND)
	file_new = 0;
	else
	flags \|= O_TRUNC;

	if (pipe_output)
	output = STDOUT_FILENO;
	else
	output = open(output_name, flags, S_IRUSR \| S_IWUSR);
	if (output < 0) {
	perror("failed to create output file");
	exit(-1);
	}

	session = perf_session__new(output_name, O_WRONLY,
	write_mode == WRITE_FORCE, false, NULL);
	if (session == NULL) {
	pr_err("Not enough memory for reading perf file header\n");
	return -1;
	}

	if (!no_buildid)
	perf_header__set_feat(&session->header, HEADER_BUILD_ID);

	if (!file_new) {
	err = perf_session__read_header(session, output);
	if (err < 0)
	goto out_delete_session;
	}

	if (have_tracepoints(&evsel_list->entries))
	perf_header__set_feat(&session->header, HEADER_TRACE_INFO);

	/* 512 kiB: default amount of unprivileged mlocked memory */
	if (mmap_pages == UINT_MAX)
	mmap_pages = (512 * 1024) / page_size;

	if (forks) {
	child_pid = fork();
	if (child_pid < 0) {
	perror("failed to fork");
	exit(-1);
	}

	if (!child_pid) {
	if (pipe_output)
	dup2(2, 1);
	close(child_ready_pipe[0]);
	close(go_pipe[1]);
	fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);

	/*
	* Do a dummy execvp to get the PLT entry resolved,
	* so we avoid the resolver overhead on the real
	* execvp call.
	*/
	execvp("", (char **)argv);

	/*
	* Tell the parent we're ready to go
	*/
	close(child_ready_pipe[1]);

	/*
	* Wait until the parent tells us to go.
	*/
	if (read(go_pipe[0], &buf, 1) == -1)
	perror("unable to read pipe");

	execvp(argv[0], (char **)argv);

	perror(argv[0]);
	kill(getppid(), SIGUSR1);
	exit(-1);
	}

	if (!system_wide && target_tid == -1 && target_pid == -1)
	evsel_list->threads->map[0] = child_pid;

	close(child_ready_pipe[1]);
	close(go_pipe[0]);
	/*
	* wait for child to settle
	*/
	if (read(child_ready_pipe[0], &buf, 1) == -1) {
	perror("unable to read pipe");
	exit(-1);
	}
	close(child_ready_pipe[0]);
	}

	open_counters(evsel_list);

	/*
	* perf_session__delete(session) will be called at atexit_header()
	*/
	atexit(atexit_header);

	if (pipe_output) {
	err = perf_header__write_pipe(output);
	if (err < 0)
	return err;
	} else if (file_new) {
	err = perf_session__write_header(session, evsel_list,
	output, false);
	if (err < 0)
	return err;
	}

	post_processing_offset = lseek(output, 0, SEEK_CUR);

	if (pipe_output) {
	err = perf_session__synthesize_attrs(session,
	process_synthesized_event);
	if (err < 0) {
	pr_err("Couldn't synthesize attrs.\n");
	return err;
	}

	err = perf_event__synthesize_event_types(process_synthesized_event,
	session);
	if (err < 0) {
	pr_err("Couldn't synthesize event_types.\n");
	return err;
	}

	if (have_tracepoints(&evsel_list->entries)) {
	/*
	* FIXME err <= 0 here actually means that
	* there were no tracepoints so its not really
	* an error, just that we don't need to
	* synthesize anything. We really have to
	* return this more properly and also
	* propagate errors that now are calling die()
	*/
	err = perf_event__synthesize_tracing_data(output, evsel_list,
	process_synthesized_event,
	session);
	if (err <= 0) {
	pr_err("Couldn't record tracing data.\n");
	return err;
	}
	advance_output(err);
	}
	}

	machine = perf_session__find_host_machine(session);
	if (!machine) {
	pr_err("Couldn't find native kernel information.\n");
	return -1;
	}

	err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
	session, machine, "_text");
	if (err < 0)
	err = perf_event__synthesize_kernel_mmap(process_synthesized_event,
	session, machine, "_stext");
	if (err < 0)
	pr_err("Couldn't record kernel reference relocation symbol\n"
	"Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
	"Check /proc/kallsyms permission or run as root.\n");

	err = perf_event__synthesize_modules(process_synthesized_event,
	session, machine);
	if (err < 0)
	pr_err("Couldn't record kernel module information.\n"
	"Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
	"Check /proc/modules permission or run as root.\n");

	if (perf_guest)
	perf_session__process_machines(session,
	perf_event__synthesize_guest_os);

	if (!system_wide)
	perf_event__synthesize_thread_map(evsel_list->threads,
	process_synthesized_event,
	session);
	else
	perf_event__synthesize_threads(process_synthesized_event,
	session);

	if (realtime_prio) {
	struct sched_param param;

	param.sched_priority = realtime_prio;
	if (sched_setscheduler(0, SCHED_FIFO, &param)) {
	pr_err("Could not set realtime priority.\n");
	exit(-1);
	}
	}

	/*
	* Let the child rip
	*/
	if (forks)
	close(go_pipe[1]);

	for (;;) {
	int hits = samples;
	int thread;

	mmap_read_all();

	if (hits == samples) {
	if (done)
	break;
	err = poll(evsel_list->pollfd, evsel_list->nr_fds, -1);
	waking++;
	}

	if (done) {
	for (i = 0; i < evsel_list->cpus->nr; i++) {
	struct perf_evsel *pos;

	list_for_each_entry(pos, &evsel_list->entries, node) {
	for (thread = 0;
	thread < evsel_list->threads->nr;
	thread++)
	ioctl(FD(pos, i, thread),
	PERF_EVENT_IOC_DISABLE);
	}
	}
	}
	}

	if (quiet \|\| signr == SIGUSR1)
	return 0;

	fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);

	/*
	* Approximate RIP event size: 24 bytes.
	*/
	fprintf(stderr,
	"[ perf record: Captured and wrote %.3f MB %s (~%" PRIu64 " samples) ]\n",
	(double)bytes_written / 1024.0 / 1024.0,
	output_name,
	bytes_written / 24);

	return 0;

	out_delete_session:
	perf_session__delete(session);
	return err;
	}

	static const char * const record_usage[] = {
	"perf record [<options>] [<command>]",
	"perf record [<options>] -- <command> [<options>]",
	NULL
	};

	static bool force, append_file;

	const struct option record_options[] = {
	OPT_CALLBACK('e', "event", &evsel_list, "event",
	"event selector. use 'perf list' to list available events",
	parse_events),
	OPT_CALLBACK(0, "filter", &evsel_list, "filter",
	"event filter", parse_filter),
	OPT_INTEGER('p', "pid", &target_pid,
	"record events on existing process id"),
	OPT_INTEGER('t', "tid", &target_tid,
	"record events on existing thread id"),
	OPT_INTEGER('r', "realtime", &realtime_prio,
	"collect data with this RT SCHED_FIFO priority"),
	OPT_BOOLEAN('D', "no-delay", &nodelay,
	"collect data without buffering"),
	OPT_BOOLEAN('R', "raw-samples", &raw_samples,
	"collect raw sample records from all opened counters"),
	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_STRING('C', "cpu", &cpu_list, "cpu",
	"list of cpus to monitor"),
	OPT_BOOLEAN('f', "force", &force,
	"overwrite existing data file (deprecated)"),
	OPT_U64('c', "count", &user_interval, "event period to sample"),
	OPT_STRING('o', "output", &output_name, "file",
	"output file name"),
	OPT_BOOLEAN('i', "no-inherit", &no_inherit,
	"child tasks do not inherit counters"),
	OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
	OPT_UINTEGER('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_INCR('v', "verbose", &verbose,
	"be more verbose (show counter open errors, etc)"),
	OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
	OPT_BOOLEAN('s', "stat", &inherit_stat,
	"per thread counts"),
	OPT_BOOLEAN('d', "data", &sample_address,
	"Sample addresses"),
	OPT_BOOLEAN('T', "timestamp", &sample_time, "Sample timestamps"),
	OPT_BOOLEAN('n', "no-samples", &no_samples,
	"don't sample"),
	OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid_cache,
	"do not update the buildid cache"),
	OPT_BOOLEAN('B', "no-buildid", &no_buildid,
	"do not collect buildids in perf.data"),
	OPT_CALLBACK('G', "cgroup", &evsel_list, "name",
	"monitor event in cgroup name only",
	parse_cgroups),
	OPT_END()
	};

	int cmd_record(int argc, const char *argv, const char prefix __used)
	{
	int err = -ENOMEM;
	struct perf_evsel *pos;

	evsel_list = perf_evlist__new(NULL, NULL);
	if (evsel_list == NULL)
	return -ENOMEM;

	argc = parse_options(argc, argv, record_options, record_usage,
	PARSE_OPT_STOP_AT_NON_OPTION);
	if (!argc && target_pid == -1 && target_tid == -1 &&
	!system_wide && !cpu_list)
	usage_with_options(record_usage, record_options);

	if (force && append_file) {
	fprintf(stderr, "Can't overwrite and append at the same time."
	" You need to choose between -f and -A");
	usage_with_options(record_usage, record_options);
	} else if (append_file) {
	write_mode = WRITE_APPEND;
	} else {
	write_mode = WRITE_FORCE;
	}

	if (nr_cgroups && !system_wide) {
	fprintf(stderr, "cgroup monitoring only available in"
	" system-wide mode\n");
	usage_with_options(record_usage, record_options);
	}

	symbol__init();

	if (no_buildid_cache \|\| no_buildid)
	disable_buildid_cache();

	if (evsel_list->nr_entries == 0 &&
	perf_evlist__add_default(evsel_list) < 0) {
	pr_err("Not enough memory for event selector list\n");
	goto out_symbol_exit;
	}

	if (target_pid != -1)
	target_tid = target_pid;

	if (perf_evlist__create_maps(evsel_list, target_pid,
	target_tid, cpu_list) < 0)
	usage_with_options(record_usage, record_options);

	list_for_each_entry(pos, &evsel_list->entries, node) {
	if (perf_evsel__alloc_fd(pos, evsel_list->cpus->nr,
	evsel_list->threads->nr) < 0)
	goto out_free_fd;
	if (perf_header__push_event(pos->attr.config, event_name(pos)))
	goto out_free_fd;
	}

	if (perf_evlist__alloc_pollfd(evsel_list) < 0)
	goto out_free_fd;

	if (user_interval != ULLONG_MAX)
	default_interval = user_interval;
	if (user_freq != UINT_MAX)
	freq = user_freq;

	/*
	* User specified count overrides default frequency.
	*/
	if (default_interval)
	freq = 0;
	else if (freq) {
	default_interval = freq;
	} else {
	fprintf(stderr, "frequency and count are zero, aborting\n");
	err = -EINVAL;
	goto out_free_fd;
	}

	err = __cmd_record(argc, argv);
	out_free_fd:
	perf_evlist__delete_maps(evsel_list);
	out_symbol_exit:
	symbol__exit();
	return err;
	}