/* * kerneltop.c: show top kernel functions - performance counters showcase Build with: make -C Documentation/perf_counter/ Sample output: ------------------------------------------------------------------------------ KernelTop: 2669 irqs/sec [cache-misses/cache-refs], (all, cpu: 2) ------------------------------------------------------------------------------ weight RIP kernel function ______ ________________ _______________ 35.20 - ffffffff804ce74b : skb_copy_and_csum_dev 33.00 - ffffffff804cb740 : sock_alloc_send_skb 31.26 - ffffffff804ce808 : skb_push 22.43 - ffffffff80510004 : tcp_established_options 19.00 - ffffffff8027d250 : find_get_page 15.76 - ffffffff804e4fc9 : eth_type_trans 15.20 - ffffffff804d8baa : dst_release 14.86 - ffffffff804cf5d8 : skb_release_head_state 14.00 - ffffffff802217d5 : read_hpet 12.00 - ffffffff804ffb7f : __ip_local_out 11.97 - ffffffff804fc0c8 : ip_local_deliver_finish 8.54 - ffffffff805001a3 : ip_queue_xmit */ /* * Copyright (C) 2008, Red Hat Inc, Ingo Molnar * * Improvements and fixes by: * * Arjan van de Ven * Yanmin Zhang * Wu Fengguang * Mike Galbraith * Paul Mackerras * * Released under the GPL v2. (and only v2, not any later version) */ #include "perf.h" #include "builtin.h" #include "util/symbol.h" #include "util/util.h" #include "util/rbtree.h" #include "util/parse-options.h" #include "util/parse-events.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int system_wide = 0; static __u64 default_event_id[MAX_COUNTERS] = { EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK), EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES), EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS), EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS), EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES), EID(PERF_TYPE_HARDWARE, PERF_COUNT_INSTRUCTIONS), EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_REFERENCES), EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_MISSES), }; static int default_interval = 100000; static int event_count[MAX_COUNTERS]; static int fd[MAX_NR_CPUS][MAX_COUNTERS]; static __u64 count_filter = 100; static int target_pid = -1; static int profile_cpu = -1; static int nr_cpus = 0; static unsigned int realtime_prio = 0; static int group = 0; static unsigned int page_size; static unsigned int mmap_pages = 16; static int use_mmap = 0; static int use_munmap = 0; static int freq = 0; static char *sym_filter; static unsigned long filter_start; static unsigned long filter_end; static int delay_secs = 2; static int zero; static int dump_symtab; static const unsigned int default_count[] = { 1000000, 1000000, 10000, 10000, 1000000, 10000, }; /* * Symbols */ static uint64_t min_ip; static uint64_t max_ip = -1ll; struct sym_entry { struct rb_node rb_node; struct list_head node; unsigned long count[MAX_COUNTERS]; unsigned long snap_count; double weight; int skip; }; struct sym_entry *sym_filter_entry; struct dso *kernel_dso; /* * Symbols will be added here in record_ip and will get out * after decayed. */ static LIST_HEAD(active_symbols); static pthread_mutex_t active_symbols_lock = PTHREAD_MUTEX_INITIALIZER; /* * Ordering weight: count-1 * count-2 * ... / count-n */ static double sym_weight(const struct sym_entry *sym) { double weight = sym->snap_count; int counter; for (counter = 1; counter < nr_counters-1; counter++) weight *= sym->count[counter]; weight /= (sym->count[counter] + 1); return weight; } static long events; static long userspace_events; static const char CONSOLE_CLEAR[] = ""; static void __list_insert_active_sym(struct sym_entry *syme) { list_add(&syme->node, &active_symbols); } static void list_remove_active_sym(struct sym_entry *syme) { pthread_mutex_lock(&active_symbols_lock); list_del_init(&syme->node); pthread_mutex_unlock(&active_symbols_lock); } static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se) { struct rb_node **p = &tree->rb_node; struct rb_node *parent = NULL; struct sym_entry *iter; while (*p != NULL) { parent = *p; iter = rb_entry(parent, struct sym_entry, rb_node); if (se->weight > iter->weight) p = &(*p)->rb_left; else p = &(*p)->rb_right; } rb_link_node(&se->rb_node, parent, p); rb_insert_color(&se->rb_node, tree); } static void print_sym_table(void) { int printed, j; int counter; float events_per_sec = events/delay_secs; float kevents_per_sec = (events-userspace_events)/delay_secs; float sum_kevents = 0.0; struct sym_entry *syme, *n; struct rb_root tmp = RB_ROOT; struct rb_node *nd; events = userspace_events = 0; /* Sort the active symbols */ pthread_mutex_lock(&active_symbols_lock); syme = list_entry(active_symbols.next, struct sym_entry, node); pthread_mutex_unlock(&active_symbols_lock); list_for_each_entry_safe_from(syme, n, &active_symbols, node) { syme->snap_count = syme->count[0]; if (syme->snap_count != 0) { syme->weight = sym_weight(syme); rb_insert_active_sym(&tmp, syme); sum_kevents += syme->snap_count; for (j = 0; j < nr_counters; j++) syme->count[j] = zero ? 0 : syme->count[j] * 7 / 8; } else list_remove_active_sym(syme); } write(1, CONSOLE_CLEAR, strlen(CONSOLE_CLEAR)); printf( "------------------------------------------------------------------------------\n"); printf( " KernelTop:%8.0f irqs/sec kernel:%4.1f%% [", events_per_sec, 100.0 - (100.0*((events_per_sec-kevents_per_sec)/events_per_sec))); if (nr_counters == 1) printf("%d ", event_count[0]); for (counter = 0; counter < nr_counters; counter++) { if (counter) printf("/"); printf("%s", event_name(counter)); } printf( "], "); if (target_pid != -1) printf(" (target_pid: %d", target_pid); else printf(" (all"); if (profile_cpu != -1) printf(", cpu: %d)\n", profile_cpu); else { if (target_pid != -1) printf(")\n"); else printf(", %d CPUs)\n", nr_cpus); } printf("------------------------------------------------------------------------------\n\n"); if (nr_counters == 1) printf(" events pcnt"); else printf(" weight events pcnt"); printf(" RIP kernel function\n" " ______ ______ _____ ________________ _______________\n\n" ); for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) { struct sym_entry *syme = rb_entry(nd, struct sym_entry, rb_node); struct symbol *sym = (struct symbol *)(syme + 1); float pcnt; if (++printed > 18 || syme->snap_count < count_filter) continue; pcnt = 100.0 - (100.0 * ((sum_kevents - syme->snap_count) / sum_kevents)); if (nr_counters == 1) printf("%19.2f - %4.1f%% - %016llx : %s\n", syme->weight, pcnt, sym->start, sym->name); else printf("%8.1f %10ld - %4.1f%% - %016llx : %s\n", syme->weight, syme->snap_count, pcnt, sym->start, sym->name); } { struct pollfd stdin_poll = { .fd = 0, .events = POLLIN }; if (poll(&stdin_poll, 1, 0) == 1) { printf("key pressed - exiting.\n"); exit(0); } } } static void *display_thread(void *arg) { printf("KernelTop refresh period: %d seconds\n", delay_secs); while (!sleep(delay_secs)) print_sym_table(); return NULL; } static int symbol_filter(struct dso *self, struct symbol *sym) { static int filter_match; struct sym_entry *syme; const char *name = sym->name; if (!strcmp(name, "_text") || !strcmp(name, "_etext") || !strcmp(name, "_sinittext") || !strncmp("init_module", name, 11) || !strncmp("cleanup_module", name, 14) || strstr(name, "_text_start") || strstr(name, "_text_end")) return 1; syme = dso__sym_priv(self, sym); /* Tag events to be skipped. */ if (!strcmp("default_idle", name) || !strcmp("cpu_idle", name) || !strcmp("enter_idle", name) || !strcmp("exit_idle", name) || !strcmp("mwait_idle", name)) syme->skip = 1; if (filter_match == 1) { filter_end = sym->start; filter_match = -1; if (filter_end - filter_start > 10000) { fprintf(stderr, "hm, too large filter symbol <%s> - skipping.\n", sym_filter); fprintf(stderr, "symbol filter start: %016lx\n", filter_start); fprintf(stderr, " end: %016lx\n", filter_end); filter_end = filter_start = 0; sym_filter = NULL; sleep(1); } } if (filter_match == 0 && sym_filter && !strcmp(name, sym_filter)) { filter_match = 1; filter_start = sym->start; } return 0; } static int parse_symbols(void) { struct rb_node *node; struct symbol *sym; kernel_dso = dso__new("[kernel]", sizeof(struct sym_entry)); if (kernel_dso == NULL) return -1; if (dso__load_kernel(kernel_dso, NULL, symbol_filter) != 0) goto out_delete_dso; node = rb_first(&kernel_dso->syms); sym = rb_entry(node, struct symbol, rb_node); min_ip = sym->start; node = rb_last(&kernel_dso->syms); sym = rb_entry(node, struct symbol, rb_node); max_ip = sym->end; if (dump_symtab) dso__fprintf(kernel_dso, stderr); return 0; out_delete_dso: dso__delete(kernel_dso); kernel_dso = NULL; return -1; } #define TRACE_COUNT 3 /* * Binary search in the histogram table and record the hit: */ static void record_ip(uint64_t ip, int counter) { struct symbol *sym = dso__find_symbol(kernel_dso, ip); if (sym != NULL) { struct sym_entry *syme = dso__sym_priv(kernel_dso, sym); if (!syme->skip) { syme->count[counter]++; pthread_mutex_lock(&active_symbols_lock); if (list_empty(&syme->node) || !syme->node.next) __list_insert_active_sym(syme); pthread_mutex_unlock(&active_symbols_lock); return; } } events--; } static void process_event(uint64_t ip, int counter) { events++; if (ip < min_ip || ip > max_ip) { userspace_events++; return; } record_ip(ip, counter); } struct mmap_data { int counter; void *base; unsigned int mask; unsigned int prev; }; static unsigned int mmap_read_head(struct mmap_data *md) { struct perf_counter_mmap_page *pc = md->base; int head; head = pc->data_head; rmb(); return head; } struct timeval last_read, this_read; 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; 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 screw up the events 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 > md->mask / 2 || 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; for (; old != head;) { struct ip_event { struct perf_event_header header; __u64 ip; __u32 pid, target_pid; }; struct mmap_event { struct perf_event_header header; __u32 pid, target_pid; __u64 start; __u64 len; __u64 pgoff; char filename[PATH_MAX]; }; typedef union event_union { struct perf_event_header header; struct ip_event ip; struct mmap_event mmap; } event_t; event_t *event = (event_t *)&data[old & md->mask]; event_t event_copy; size_t size = event->header.size; /* * Event straddles the mmap boundary -- header should always * be inside due to u64 alignment of output. */ if ((old & md->mask) + size != ((old + size) & md->mask)) { unsigned int offset = old; unsigned int len = min(sizeof(*event), size), cpy; void *dst = &event_copy; do { cpy = min(md->mask + 1 - (offset & md->mask), len); memcpy(dst, &data[offset & md->mask], cpy); offset += cpy; dst += cpy; len -= cpy; } while (len); event = &event_copy; } old += size; if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) { if (event->header.type & PERF_SAMPLE_IP) process_event(event->ip.ip, md->counter); } else { switch (event->header.type) { case PERF_EVENT_MMAP: case PERF_EVENT_MUNMAP: printf("%s: %Lu %Lu %Lu %s\n", event->header.type == PERF_EVENT_MMAP ? "mmap" : "munmap", event->mmap.start, event->mmap.len, event->mmap.pgoff, event->mmap.filename); break; } } } md->prev = old; } static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS]; static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; static int __cmd_top(void) { struct perf_counter_attr attr; pthread_t thread; int i, counter, group_fd, nr_poll = 0; unsigned int cpu; int ret; for (i = 0; i < nr_cpus; i++) { group_fd = -1; for (counter = 0; counter < nr_counters; counter++) { cpu = profile_cpu; if (target_pid == -1 && profile_cpu == -1) cpu = i; memset(&attr, 0, sizeof(attr)); attr.config = event_id[counter]; attr.sample_period = event_count[counter]; attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID; attr.mmap = use_mmap; attr.munmap = use_munmap; attr.freq = freq; fd[i][counter] = sys_perf_counter_open(&attr, target_pid, cpu, group_fd, 0); if (fd[i][counter] < 0) { int err = errno; printf("kerneltop error: syscall returned with %d (%s)\n", fd[i][counter], strerror(err)); if (err == EPERM) printf("Are you root?\n"); exit(-1); } assert(fd[i][counter] >= 0); fcntl(fd[i][counter], F_SETFL, O_NONBLOCK); /* * First counter acts as the group leader: */ if (group && group_fd == -1) group_fd = fd[i][counter]; event_array[nr_poll].fd = fd[i][counter]; event_array[nr_poll].events = POLLIN; nr_poll++; mmap_array[i][counter].counter = counter; mmap_array[i][counter].prev = 0; mmap_array[i][counter].mask = mmap_pages*page_size - 1; mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size, PROT_READ, MAP_SHARED, fd[i][counter], 0); if (mmap_array[i][counter].base == MAP_FAILED) { printf("kerneltop error: failed to mmap with %d (%s)\n", errno, strerror(errno)); exit(-1); } } } if (pthread_create(&thread, NULL, display_thread, NULL)) { printf("Could not create display thread.\n"); exit(-1); } if (realtime_prio) { struct sched_param param; param.sched_priority = realtime_prio; if (sched_setscheduler(0, SCHED_FIFO, ¶m)) { printf("Could not set realtime priority.\n"); exit(-1); } } while (1) { int hits = events; for (i = 0; i < nr_cpus; i++) { for (counter = 0; counter < nr_counters; counter++) mmap_read(&mmap_array[i][counter]); } if (hits == events) ret = poll(event_array, nr_poll, 100); } return 0; } static const char * const top_usage[] = { "perf top []", NULL }; static char events_help_msg[EVENTS_HELP_MAX]; static const struct option options[] = { OPT_CALLBACK('e', "event", NULL, "event", events_help_msg, parse_events), OPT_INTEGER('c', "count", &default_interval, "event period to sample"), OPT_INTEGER('p', "pid", &target_pid, "profile events on existing pid"), OPT_BOOLEAN('a', "all-cpus", &system_wide, "system-wide collection from all CPUs"), OPT_INTEGER('C', "CPU", &profile_cpu, "CPU to profile on"), OPT_INTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"), OPT_INTEGER('r', "realtime", &realtime_prio, "collect data with this RT SCHED_FIFO priority"), OPT_INTEGER('d', "delay", &delay_secs, "number of seconds to delay between refreshes"), OPT_BOOLEAN('D', "dump-symtab", &dump_symtab, "dump the symbol table used for profiling"), OPT_INTEGER('f', "--count-filter", &count_filter, "only display functions with more events than this"), OPT_BOOLEAN('g', "group", &group, "put the counters into a counter group"), OPT_STRING('s', "sym-filter", &sym_filter, "pattern", "only display symbols matchig this pattern"), OPT_BOOLEAN('z', "zero", &group, "zero history across updates"), OPT_BOOLEAN('M', "use-mmap", &use_mmap, "track mmap events"), OPT_BOOLEAN('U', "use-munmap", &use_munmap, "track munmap events"), OPT_INTEGER('F', "--freq", &freq, "profile at this frequency"), OPT_END() }; int cmd_top(int argc, const char **argv, const char *prefix) { int counter; page_size = sysconf(_SC_PAGE_SIZE); create_events_help(events_help_msg); memcpy(event_id, default_event_id, sizeof(default_event_id)); argc = parse_options(argc, argv, options, top_usage, 0); if (argc) usage_with_options(top_usage, options); if (freq) { default_interval = freq; freq = 1; } /* CPU and PID are mutually exclusive */ if (target_pid != -1 && profile_cpu != -1) { printf("WARNING: PID switch overriding CPU\n"); sleep(1); profile_cpu = -1; } if (!nr_counters) { nr_counters = 1; event_id[0] = 0; } for (counter = 0; counter < nr_counters; counter++) { if (event_count[counter]) continue; event_count[counter] = default_interval; } nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); assert(nr_cpus <= MAX_NR_CPUS); assert(nr_cpus >= 0); if (target_pid != -1 || profile_cpu != -1) nr_cpus = 1; parse_symbols(); return __cmd_top(); }