/* * 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/debug.h" #include "util/session.h" #include "util/symbol.h" #include "util/cpumap.h" #include <unistd.h> #include <sched.h> #include <sys/mman.h> enum write_mode_t { WRITE_FORCE, WRITE_APPEND }; static int *fd[MAX_NR_CPUS][MAX_COUNTERS]; static u64 user_interval = ULLONG_MAX; static u64 default_interval = 0; static int nr_cpus = 0; static unsigned int page_size; static unsigned int mmap_pages = 128; static unsigned int user_freq = UINT_MAX; static int freq = 1000; static int output; static int pipe_output = 0; static const char *output_name = "perf.data"; static int group = 0; static int realtime_prio = 0; static bool raw_samples = false; static bool system_wide = false; static pid_t target_pid = -1; static pid_t target_tid = -1; static pid_t *all_tids = NULL; static int thread_num = 0; 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 no_buildid = false; static long samples = 0; static u64 bytes_written = 0; static struct pollfd *event_array; static int nr_poll = 0; static int nr_cpu = 0; static int file_new = 1; static off_t post_processing_offset; static struct perf_session *session; static const char *cpu_list; struct mmap_data { int counter; void *base; unsigned int mask; unsigned int prev; }; static struct mmap_data mmap_array[MAX_NR_CPUS]; static unsigned long mmap_read_head(struct mmap_data *md) { struct perf_event_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_event_mmap_page *pc = md->base; /* * ensure all reads are done before we write the tail out. */ /* mb(); */ pc->data_tail = tail; } 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(event_t *event, struct perf_session *self __used) { write_output(event, event->header.size); return 0; } 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; /* * 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) { fprintf(stderr, "WARNING: failed to keep up with mmap data\n"); /* * head points to a known good entry, start there. */ old = head; } 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 (child_pid > 0) kill(child_pid, SIGTERM); if (signr == -1) return; signal(signr, SIG_DFL); kill(getpid(), signr); } static int group_fd; static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr) { struct perf_header_attr *h_attr; if (nr < session->header.attrs) { h_attr = session->header.attr[nr]; } else { h_attr = perf_header_attr__new(a); if (h_attr != NULL) if (perf_header__add_attr(&session->header, h_attr) < 0) { perf_header_attr__delete(h_attr); h_attr = NULL; } } return h_attr; } static void create_counter(int counter, int cpu) { char *filter = filters[counter]; struct perf_event_attr *attr = attrs + counter; struct perf_header_attr *h_attr; int track = !counter; /* only the first counter needs these */ int thread_index; int ret; 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 (nr_counters > 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 (raw_samples) { attr->sample_type |= PERF_SAMPLE_TIME; attr->sample_type |= PERF_SAMPLE_RAW; attr->sample_type |= PERF_SAMPLE_CPU; } attr->mmap = track; attr->comm = track; attr->inherit = !no_inherit; if (target_pid == -1 && target_tid == -1 && !system_wide) { attr->disabled = 1; attr->enable_on_exec = 1; } for (thread_index = 0; thread_index < thread_num; thread_index++) { try_again: fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr, all_tids[thread_index], cpu, group_fd, 0); if (fd[nr_cpu][counter][thread_index] < 0) { int err = errno; if (err == EPERM || err == EACCES) die("Permission error - are you root?\n" "\t Consider tweaking" " /proc/sys/kernel/perf_event_paranoid.\n"); else if (err == ENODEV && cpu_list) { die("No such device - did you specify" " an out-of-range profile CPU?\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][thread_index], 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"); exit(-1); } h_attr = get_header_attr(attr, counter); if (h_attr == NULL) die("nomem\n"); if (!file_new) { if (memcmp(&h_attr->attr, attr, sizeof(*attr))) { fprintf(stderr, "incompatible append\n"); exit(-1); } } if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) { perror("Unable to read perf file descriptor\n"); exit(-1); } if (perf_header_attr__add_id(h_attr, read_data.id) < 0) { pr_warning("Not enough memory to add id\n"); exit(-1); } assert(fd[nr_cpu][counter][thread_index] >= 0); fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK); /* * First counter acts as the group leader: */ if (group && group_fd == -1) group_fd = fd[nr_cpu][counter][thread_index]; if (counter || thread_index) { ret = ioctl(fd[nr_cpu][counter][thread_index], PERF_EVENT_IOC_SET_OUTPUT, fd[nr_cpu][0][0]); if (ret) { error("failed to set output: %d (%s)\n", errno, strerror(errno)); exit(-1); } } else { mmap_array[nr_cpu].counter = counter; mmap_array[nr_cpu].prev = 0; mmap_array[nr_cpu].mask = mmap_pages*page_size - 1; mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0); if (mmap_array[nr_cpu].base == MAP_FAILED) { error("failed to mmap with %d (%s)\n", errno, strerror(errno)); exit(-1); } event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index]; event_array[nr_poll].events = POLLIN; nr_poll++; } if (filter != NULL) { ret = ioctl(fd[nr_cpu][counter][thread_index], PERF_EVENT_IOC_SET_FILTER, filter); if (ret) { error("failed to set filter with %d (%s)\n", errno, strerror(errno)); exit(-1); } } } } static void open_counters(int cpu) { int counter; group_fd = -1; for (counter = 0; counter < nr_counters; counter++) create_counter(counter, cpu); nr_cpu++; } 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; process_buildids(); perf_header__write(&session->header, output, true); perf_session__delete(session); symbol__exit(); } } static void 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 = 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 = event__synthesize_kernel_mmap(process_synthesized_event, psession, machine, "_text"); if (err < 0) err = 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 < nr_cpu; i++) { if (mmap_array[i].base) mmap_read(&mmap_array[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, counter; 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); if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) { perror("failed to create pipes"); exit(-1); } 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); if (session == NULL) { pr_err("Not enough memory for reading perf file header\n"); return -1; } if (!file_new) { err = perf_header__read(session, output); if (err < 0) goto out_delete_session; } if (have_tracepoints(attrs, nr_counters)) perf_header__set_feat(&session->header, HEADER_TRACE_INFO); /* * perf_session__delete(session) will be called at atexit_header() */ atexit(atexit_header); 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]); exit(-1); } if (!system_wide && target_tid == -1 && target_pid == -1) all_tids[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]); } nr_cpus = read_cpu_map(cpu_list); if (nr_cpus < 1) { perror("failed to collect number of CPUs\n"); return -1; } if (!system_wide && no_inherit && !cpu_list) { open_counters(-1); } else { for (i = 0; i < nr_cpus; i++) open_counters(cpumap[i]); } if (pipe_output) { err = perf_header__write_pipe(output); if (err < 0) return err; } else if (file_new) { err = perf_header__write(&session->header, output, false); if (err < 0) return err; } post_processing_offset = lseek(output, 0, SEEK_CUR); if (pipe_output) { err = event__synthesize_attrs(&session->header, process_synthesized_event, session); if (err < 0) { pr_err("Couldn't synthesize attrs.\n"); return err; } err = event__synthesize_event_types(process_synthesized_event, session); if (err < 0) { pr_err("Couldn't synthesize event_types.\n"); return err; } if (have_tracepoints(attrs, nr_counters)) { /* * 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 = event__synthesize_tracing_data(output, attrs, nr_counters, 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 = event__synthesize_kernel_mmap(process_synthesized_event, session, machine, "_text"); if (err < 0) err = event__synthesize_kernel_mmap(process_synthesized_event, session, machine, "_stext"); if (err < 0) { pr_err("Couldn't record kernel reference relocation symbol.\n"); return err; } err = event__synthesize_modules(process_synthesized_event, session, machine); if (err < 0) { pr_err("Couldn't record kernel reference relocation symbol.\n"); return err; } if (perf_guest) perf_session__process_machines(session, event__synthesize_guest_os); if (!system_wide) event__synthesize_thread(target_tid, process_synthesized_event, session); else 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, ¶m)) { 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(event_array, nr_poll, -1); waking++; } if (done) { for (i = 0; i < nr_cpu; i++) { for (counter = 0; counter < nr_counters; counter++) { for (thread = 0; thread < thread_num; thread++) ioctl(fd[i][counter][thread], PERF_EVENT_IOC_DISABLE); } } } } 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 (~%lld 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; static const struct option options[] = { OPT_CALLBACK('e', "event", NULL, "event", "event selector. use 'perf list' to list available events", parse_events), OPT_CALLBACK(0, "filter", NULL, "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('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('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_BOOLEAN('N', "no-buildid-cache", &no_buildid, "do not update the buildid cache"), OPT_END() }; int cmd_record(int argc, const char **argv, const char *prefix __used) { int i, j, err = -ENOMEM; argc = parse_options(argc, argv, 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, 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, options); } else if (append_file) { write_mode = WRITE_APPEND; } else { write_mode = WRITE_FORCE; } symbol__init(); if (no_buildid) disable_buildid_cache(); if (!nr_counters) { nr_counters = 1; attrs[0].type = PERF_TYPE_HARDWARE; attrs[0].config = PERF_COUNT_HW_CPU_CYCLES; } if (target_pid != -1) { target_tid = target_pid; thread_num = find_all_tid(target_pid, &all_tids); if (thread_num <= 0) { fprintf(stderr, "Can't find all threads of pid %d\n", target_pid); usage_with_options(record_usage, options); } } else { all_tids=malloc(sizeof(pid_t)); if (!all_tids) goto out_symbol_exit; all_tids[0] = target_tid; thread_num = 1; } for (i = 0; i < MAX_NR_CPUS; i++) { for (j = 0; j < MAX_COUNTERS; j++) { fd[i][j] = malloc(sizeof(int)*thread_num); if (!fd[i][j]) goto out_free_fd; } } event_array = malloc( sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num); if (!event_array) 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_event_array; } err = __cmd_record(argc, argv); out_free_event_array: free(event_array); out_free_fd: for (i = 0; i < MAX_NR_CPUS; i++) { for (j = 0; j < MAX_COUNTERS; j++) free(fd[i][j]); } free(all_tids); all_tids = NULL; out_symbol_exit: symbol__exit(); return err; }