/* * builtin-record.c * * Builtin record command: Record the profile of a workload * (or a CPU, or a PID) into the perf.data output file - for * later analysis via perf report. */ #include "builtin.h" #include "perf.h" #include "util/util.h" #include "util/parse-options.h" #include "util/parse-events.h" #include "util/string.h" #include "util/header.h" #include "util/event.h" #include "util/debug.h" #include "util/session.h" #include "util/symbol.h" #include <unistd.h> #include <sched.h> static int fd[MAX_NR_CPUS][MAX_COUNTERS]; static long default_interval = 0; static int nr_cpus = 0; static unsigned int page_size; static unsigned int mmap_pages = 128; static int freq = 1000; static int output; static const char *output_name = "perf.data"; static int group = 0; static unsigned int realtime_prio = 0; static int raw_samples = 0; static int system_wide = 0; static int profile_cpu = -1; static pid_t target_pid = -1; static pid_t child_pid = -1; static int inherit = 1; static int force = 0; static int append_file = 0; static int call_graph = 0; static int inherit_stat = 0; static int no_samples = 0; static int sample_address = 0; static int multiplex = 0; static int multiplex_fd = -1; static long samples = 0; static struct timeval last_read; static struct timeval this_read; static u64 bytes_written = 0; static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS]; static int nr_poll = 0; static int nr_cpu = 0; static int file_new = 1; static struct perf_session *session; struct mmap_data { int counter; void *base; unsigned int mask; unsigned int prev; }; static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; static unsigned long mmap_read_head(struct mmap_data *md) { struct perf_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 write_output(void *buf, size_t size) { while (size) { int ret = write(output, buf, size); if (ret < 0) die("failed to write"); size -= ret; buf += ret; bytes_written += ret; } } static void write_event(event_t *buf, size_t size) { /* * Add it to the list of DSOs, so that when we finish this * record session we can pick the available build-ids. */ if (buf->header.type == PERF_RECORD_MMAP) dsos__findnew(buf->mmap.filename); write_output(buf, size); } static int process_synthesized_event(event_t *event, struct perf_session *self __used) { write_event(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; gettimeofday(&this_read, NULL); /* * If we're further behind than half the buffer, there's a chance * the writer will bite our tail and mess up the samples under us. * * If we somehow ended up ahead of the head, we got messed up. * * In either case, truncate and restart at head. */ diff = head - old; if (diff < 0) { struct timeval iv; unsigned long msecs; timersub(&this_read, &last_read, &iv); msecs = iv.tv_sec*1000 + iv.tv_usec/1000; fprintf(stderr, "WARNING: failed to keep up with mmap data." " Last read %lu msecs ago.\n", msecs); /* * head points to a known good entry, start there. */ old = head; } last_read = this_read; if (old != head) samples++; size = head - old; if ((old & md->mask) + size != (head & md->mask)) { buf = &data[old & md->mask]; size = md->mask + 1 - (old & md->mask); old += size; write_event(buf, size); } buf = &data[old & md->mask]; size = head - old; old += size; write_event(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 != -1) 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, pid_t pid) { 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 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 (freq) { attr->sample_type |= PERF_SAMPLE_PERIOD; attr->freq = 1; attr->sample_freq = freq; } if (no_samples) attr->sample_freq = 0; if (inherit_stat) attr->inherit_stat = 1; if (sample_address) attr->sample_type |= PERF_SAMPLE_ADDR; if (call_graph) attr->sample_type |= PERF_SAMPLE_CALLCHAIN; 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 = inherit; attr->disabled = 1; try_again: fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0); if (fd[nr_cpu][counter] < 0) { int err = errno; if (err == EPERM || err == EACCES) die("Permission error - are you root?\n"); else if (err == ENODEV && profile_cpu != -1) 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], 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], &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] >= 0); fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK); /* * First counter acts as the group leader: */ if (group && group_fd == -1) group_fd = fd[nr_cpu][counter]; if (multiplex && multiplex_fd == -1) multiplex_fd = fd[nr_cpu][counter]; if (multiplex && fd[nr_cpu][counter] != multiplex_fd) { ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd); assert(ret != -1); } else { event_array[nr_poll].fd = fd[nr_cpu][counter]; event_array[nr_poll].events = POLLIN; nr_poll++; mmap_array[nr_cpu][counter].counter = counter; mmap_array[nr_cpu][counter].prev = 0; mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1; mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0); if (mmap_array[nr_cpu][counter].base == MAP_FAILED) { error("failed to mmap with %d (%s)\n", errno, strerror(errno)); exit(-1); } } if (filter != NULL) { ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_FILTER, filter); if (ret) { error("failed to set filter with %d (%s)\n", errno, strerror(errno)); exit(-1); } } ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE); } static void open_counters(int cpu, pid_t pid) { int counter; group_fd = -1; for (counter = 0; counter < nr_counters; counter++) create_counter(counter, cpu, pid); nr_cpu++; } static void atexit_header(void) { session->header.data_size += bytes_written; perf_header__write(&session->header, output, true); } static int __cmd_record(int argc __used, const char **argv) { int i, counter; struct stat st; pid_t pid = 0; int flags; int err; unsigned long waking = 0; int child_ready_pipe[2], go_pipe[2]; char buf; page_size = sysconf(_SC_PAGE_SIZE); nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); assert(nr_cpus <= MAX_NR_CPUS); assert(nr_cpus >= 0); atexit(sig_atexit); signal(SIGCHLD, sig_handler); signal(SIGINT, sig_handler); if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) { perror("failed to create pipes"); exit(-1); } if (!stat(output_name, &st) && st.st_size) { if (!force) { if (!append_file) { pr_err("Error, output file %s exists, use -A " "to append or -f to overwrite.\n", output_name); exit(-1); } } else { char oldname[PATH_MAX]; snprintf(oldname, sizeof(oldname), "%s.old", output_name); unlink(oldname); rename(output_name, oldname); } } else { append_file = 0; } flags = O_CREAT|O_RDWR; if (append_file) file_new = 0; else flags |= O_TRUNC; output = open(output_name, flags, S_IRUSR|S_IWUSR); if (output < 0) { perror("failed to create output file"); exit(-1); } session = perf_session__new(output_name, O_WRONLY, force); if (session == NULL) { pr_err("Not enough memory for reading perf file header\n"); return -1; } if (!file_new) { err = perf_header__read(&session->header, output); if (err < 0) return err; } if (raw_samples) { perf_header__set_feat(&session->header, HEADER_TRACE_INFO); } else { for (i = 0; i < nr_counters; i++) { if (attrs[i].sample_type & PERF_SAMPLE_RAW) { perf_header__set_feat(&session->header, HEADER_TRACE_INFO); break; } } } atexit(atexit_header); if (target_pid == -1) { pid = fork(); if (pid < 0) { perror("failed to fork"); exit(-1); } if (!pid) { 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); } child_pid = pid; if (!system_wide) target_pid = 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]); } if ((!system_wide && !inherit) || profile_cpu != -1) { open_counters(profile_cpu, target_pid); } else { for (i = 0; i < nr_cpus; i++) open_counters(i, target_pid); } if (file_new) { err = perf_header__write(&session->header, output, false); if (err < 0) return err; } if (!system_wide) event__synthesize_thread(pid, 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 */ close(go_pipe[1]); for (;;) { int hits = samples; for (i = 0; i < nr_cpu; i++) { for (counter = 0; counter < nr_counters; counter++) { if (mmap_array[i][counter].base) mmap_read(&mmap_array[i][counter]); } } 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++) ioctl(fd[i][counter], 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; } static const char * const record_usage[] = { "perf record [<options>] [<command>]", "perf record [<options>] -- <command> [<options>]", NULL }; static const struct option options[] = { OPT_CALLBACK('e', "event", NULL, "event", "event selector. use 'perf list' to list available events", parse_events), OPT_CALLBACK(0, "filter", NULL, "filter", "event filter", parse_filter), OPT_INTEGER('p', "pid", &target_pid, "record events on existing pid"), OPT_INTEGER('r', "realtime", &realtime_prio, "collect data with this RT SCHED_FIFO priority"), OPT_BOOLEAN('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_INTEGER('C', "profile_cpu", &profile_cpu, "CPU to profile on"), OPT_BOOLEAN('f', "force", &force, "overwrite existing data file"), OPT_LONG('c', "count", &default_interval, "event period to sample"), OPT_STRING('o', "output", &output_name, "file", "output file name"), OPT_BOOLEAN('i', "inherit", &inherit, "child tasks inherit counters"), OPT_INTEGER('F', "freq", &freq, "profile at this frequency"), OPT_INTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"), OPT_BOOLEAN('g', "call-graph", &call_graph, "do call-graph (stack chain/backtrace) recording"), OPT_BOOLEAN('v', "verbose", &verbose, "be more verbose (show counter open errors, etc)"), OPT_BOOLEAN('s', "stat", &inherit_stat, "per thread counts"), OPT_BOOLEAN('d', "data", &sample_address, "Sample addresses"), OPT_BOOLEAN('n', "no-samples", &no_samples, "don't sample"), OPT_BOOLEAN('M', "multiplex", &multiplex, "multiplex counter output in a single channel"), OPT_END() }; int cmd_record(int argc, const char **argv, const char *prefix __used) { int counter; argc = parse_options(argc, argv, options, record_usage, PARSE_OPT_STOP_AT_NON_OPTION); if (!argc && target_pid == -1 && (!system_wide || profile_cpu == -1)) usage_with_options(record_usage, options); symbol__init(); if (!nr_counters) { nr_counters = 1; attrs[0].type = PERF_TYPE_HARDWARE; attrs[0].config = PERF_COUNT_HW_CPU_CYCLES; } /* * 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"); exit(EXIT_FAILURE); } for (counter = 0; counter < nr_counters; counter++) { if (attrs[counter].sample_period) continue; attrs[counter].sample_period = default_interval; } return __cmd_record(argc, argv); }