// SPDX-License-Identifier: GPL-2.0 #include #include #include "builtin.h" #include "perf.h" #include "util/evlist.h" // for struct evsel_str_handler #include "util/evsel.h" #include "util/symbol.h" #include "util/thread.h" #include "util/header.h" #include "util/target.h" #include "util/callchain.h" #include "util/lock-contention.h" #include #include #include "util/trace-event.h" #include "util/tracepoint.h" #include "util/debug.h" #include "util/session.h" #include "util/tool.h" #include "util/data.h" #include "util/string2.h" #include "util/map.h" #include #include #include #include #include #include #include #include #include #include #include #include static struct perf_session *session; static struct target target; /* based on kernel/lockdep.c */ #define LOCKHASH_BITS 12 #define LOCKHASH_SIZE (1UL << LOCKHASH_BITS) static struct hlist_head lockhash_table[LOCKHASH_SIZE]; #define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS) #define lockhashentry(key) (lockhash_table + __lockhashfn((key))) static struct rb_root thread_stats; static bool combine_locks; static bool show_thread_stats; static bool use_bpf; static unsigned long bpf_map_entries = 10240; static enum { LOCK_AGGR_ADDR, LOCK_AGGR_TASK, LOCK_AGGR_CALLER, } aggr_mode = LOCK_AGGR_ADDR; static u64 sched_text_start; static u64 sched_text_end; static u64 lock_text_start; static u64 lock_text_end; static struct thread_stat *thread_stat_find(u32 tid) { struct rb_node *node; struct thread_stat *st; node = thread_stats.rb_node; while (node) { st = container_of(node, struct thread_stat, rb); if (st->tid == tid) return st; else if (tid < st->tid) node = node->rb_left; else node = node->rb_right; } return NULL; } static void thread_stat_insert(struct thread_stat *new) { struct rb_node **rb = &thread_stats.rb_node; struct rb_node *parent = NULL; struct thread_stat *p; while (*rb) { p = container_of(*rb, struct thread_stat, rb); parent = *rb; if (new->tid < p->tid) rb = &(*rb)->rb_left; else if (new->tid > p->tid) rb = &(*rb)->rb_right; else BUG_ON("inserting invalid thread_stat\n"); } rb_link_node(&new->rb, parent, rb); rb_insert_color(&new->rb, &thread_stats); } static struct thread_stat *thread_stat_findnew_after_first(u32 tid) { struct thread_stat *st; st = thread_stat_find(tid); if (st) return st; st = zalloc(sizeof(struct thread_stat)); if (!st) { pr_err("memory allocation failed\n"); return NULL; } st->tid = tid; INIT_LIST_HEAD(&st->seq_list); thread_stat_insert(st); return st; } static struct thread_stat *thread_stat_findnew_first(u32 tid); static struct thread_stat *(*thread_stat_findnew)(u32 tid) = thread_stat_findnew_first; static struct thread_stat *thread_stat_findnew_first(u32 tid) { struct thread_stat *st; st = zalloc(sizeof(struct thread_stat)); if (!st) { pr_err("memory allocation failed\n"); return NULL; } st->tid = tid; INIT_LIST_HEAD(&st->seq_list); rb_link_node(&st->rb, NULL, &thread_stats.rb_node); rb_insert_color(&st->rb, &thread_stats); thread_stat_findnew = thread_stat_findnew_after_first; return st; } /* build simple key function one is bigger than two */ #define SINGLE_KEY(member) \ static int lock_stat_key_ ## member(struct lock_stat *one, \ struct lock_stat *two) \ { \ return one->member > two->member; \ } SINGLE_KEY(nr_acquired) SINGLE_KEY(nr_contended) SINGLE_KEY(avg_wait_time) SINGLE_KEY(wait_time_total) SINGLE_KEY(wait_time_max) static int lock_stat_key_wait_time_min(struct lock_stat *one, struct lock_stat *two) { u64 s1 = one->wait_time_min; u64 s2 = two->wait_time_min; if (s1 == ULLONG_MAX) s1 = 0; if (s2 == ULLONG_MAX) s2 = 0; return s1 > s2; } struct lock_key { /* * name: the value for specify by user * this should be simpler than raw name of member * e.g. nr_acquired -> acquired, wait_time_total -> wait_total */ const char *name; /* header: the string printed on the header line */ const char *header; /* len: the printing width of the field */ int len; /* key: a pointer to function to compare two lock stats for sorting */ int (*key)(struct lock_stat*, struct lock_stat*); /* print: a pointer to function to print a given lock stats */ void (*print)(struct lock_key*, struct lock_stat*); /* list: list entry to link this */ struct list_head list; }; static void lock_stat_key_print_time(unsigned long long nsec, int len) { static const struct { float base; const char *unit; } table[] = { { 1e9 * 3600, "h " }, { 1e9 * 60, "m " }, { 1e9, "s " }, { 1e6, "ms" }, { 1e3, "us" }, { 0, NULL }, }; for (int i = 0; table[i].unit; i++) { if (nsec < table[i].base) continue; pr_info("%*.2f %s", len - 3, nsec / table[i].base, table[i].unit); return; } pr_info("%*llu %s", len - 3, nsec, "ns"); } #define PRINT_KEY(member) \ static void lock_stat_key_print_ ## member(struct lock_key *key, \ struct lock_stat *ls) \ { \ pr_info("%*llu", key->len, (unsigned long long)ls->member); \ } #define PRINT_TIME(member) \ static void lock_stat_key_print_ ## member(struct lock_key *key, \ struct lock_stat *ls) \ { \ lock_stat_key_print_time((unsigned long long)ls->member, key->len); \ } PRINT_KEY(nr_acquired) PRINT_KEY(nr_contended) PRINT_TIME(avg_wait_time) PRINT_TIME(wait_time_total) PRINT_TIME(wait_time_max) static void lock_stat_key_print_wait_time_min(struct lock_key *key, struct lock_stat *ls) { u64 wait_time = ls->wait_time_min; if (wait_time == ULLONG_MAX) wait_time = 0; lock_stat_key_print_time(wait_time, key->len); } static const char *sort_key = "acquired"; static int (*compare)(struct lock_stat *, struct lock_stat *); static struct rb_root sorted; /* place to store intermediate data */ static struct rb_root result; /* place to store sorted data */ static LIST_HEAD(lock_keys); static const char *output_fields; #define DEF_KEY_LOCK(name, header, fn_suffix, len) \ { #name, header, len, lock_stat_key_ ## fn_suffix, lock_stat_key_print_ ## fn_suffix, {} } static struct lock_key report_keys[] = { DEF_KEY_LOCK(acquired, "acquired", nr_acquired, 10), DEF_KEY_LOCK(contended, "contended", nr_contended, 10), DEF_KEY_LOCK(avg_wait, "avg wait", avg_wait_time, 12), DEF_KEY_LOCK(wait_total, "total wait", wait_time_total, 12), DEF_KEY_LOCK(wait_max, "max wait", wait_time_max, 12), DEF_KEY_LOCK(wait_min, "min wait", wait_time_min, 12), /* extra comparisons much complicated should be here */ { } }; static struct lock_key contention_keys[] = { DEF_KEY_LOCK(contended, "contended", nr_contended, 10), DEF_KEY_LOCK(wait_total, "total wait", wait_time_total, 12), DEF_KEY_LOCK(wait_max, "max wait", wait_time_max, 12), DEF_KEY_LOCK(wait_min, "min wait", wait_time_min, 12), DEF_KEY_LOCK(avg_wait, "avg wait", avg_wait_time, 12), /* extra comparisons much complicated should be here */ { } }; static int select_key(bool contention) { int i; struct lock_key *keys = report_keys; if (contention) keys = contention_keys; for (i = 0; keys[i].name; i++) { if (!strcmp(keys[i].name, sort_key)) { compare = keys[i].key; /* selected key should be in the output fields */ if (list_empty(&keys[i].list)) list_add_tail(&keys[i].list, &lock_keys); return 0; } } pr_err("Unknown compare key: %s\n", sort_key); return -1; } static int add_output_field(bool contention, char *name) { int i; struct lock_key *keys = report_keys; if (contention) keys = contention_keys; for (i = 0; keys[i].name; i++) { if (strcmp(keys[i].name, name)) continue; /* prevent double link */ if (list_empty(&keys[i].list)) list_add_tail(&keys[i].list, &lock_keys); return 0; } pr_err("Unknown output field: %s\n", name); return -1; } static int setup_output_field(bool contention, const char *str) { char *tok, *tmp, *orig; int i, ret = 0; struct lock_key *keys = report_keys; if (contention) keys = contention_keys; /* no output field given: use all of them */ if (str == NULL) { for (i = 0; keys[i].name; i++) list_add_tail(&keys[i].list, &lock_keys); return 0; } for (i = 0; keys[i].name; i++) INIT_LIST_HEAD(&keys[i].list); orig = tmp = strdup(str); if (orig == NULL) return -ENOMEM; while ((tok = strsep(&tmp, ",")) != NULL){ ret = add_output_field(contention, tok); if (ret < 0) break; } free(orig); return ret; } static void combine_lock_stats(struct lock_stat *st) { struct rb_node **rb = &sorted.rb_node; struct rb_node *parent = NULL; struct lock_stat *p; int ret; while (*rb) { p = container_of(*rb, struct lock_stat, rb); parent = *rb; if (st->name && p->name) ret = strcmp(st->name, p->name); else ret = !!st->name - !!p->name; if (ret == 0) { p->nr_acquired += st->nr_acquired; p->nr_contended += st->nr_contended; p->wait_time_total += st->wait_time_total; if (p->nr_contended) p->avg_wait_time = p->wait_time_total / p->nr_contended; if (p->wait_time_min > st->wait_time_min) p->wait_time_min = st->wait_time_min; if (p->wait_time_max < st->wait_time_max) p->wait_time_max = st->wait_time_max; p->broken |= st->broken; st->combined = 1; return; } if (ret < 0) rb = &(*rb)->rb_left; else rb = &(*rb)->rb_right; } rb_link_node(&st->rb, parent, rb); rb_insert_color(&st->rb, &sorted); } static void insert_to_result(struct lock_stat *st, int (*bigger)(struct lock_stat *, struct lock_stat *)) { struct rb_node **rb = &result.rb_node; struct rb_node *parent = NULL; struct lock_stat *p; if (combine_locks && st->combined) return; while (*rb) { p = container_of(*rb, struct lock_stat, rb); parent = *rb; if (bigger(st, p)) rb = &(*rb)->rb_left; else rb = &(*rb)->rb_right; } rb_link_node(&st->rb, parent, rb); rb_insert_color(&st->rb, &result); } /* returns left most element of result, and erase it */ static struct lock_stat *pop_from_result(void) { struct rb_node *node = result.rb_node; if (!node) return NULL; while (node->rb_left) node = node->rb_left; rb_erase(node, &result); return container_of(node, struct lock_stat, rb); } static struct lock_stat *lock_stat_find(u64 addr) { struct hlist_head *entry = lockhashentry(addr); struct lock_stat *ret; hlist_for_each_entry(ret, entry, hash_entry) { if (ret->addr == addr) return ret; } return NULL; } static struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags) { struct hlist_head *entry = lockhashentry(addr); struct lock_stat *ret, *new; hlist_for_each_entry(ret, entry, hash_entry) { if (ret->addr == addr) return ret; } new = zalloc(sizeof(struct lock_stat)); if (!new) goto alloc_failed; new->addr = addr; new->name = strdup(name); if (!new->name) { free(new); goto alloc_failed; } new->flags = flags; new->wait_time_min = ULLONG_MAX; hlist_add_head(&new->hash_entry, entry); return new; alloc_failed: pr_err("memory allocation failed\n"); return NULL; } struct trace_lock_handler { /* it's used on CONFIG_LOCKDEP */ int (*acquire_event)(struct evsel *evsel, struct perf_sample *sample); /* it's used on CONFIG_LOCKDEP && CONFIG_LOCK_STAT */ int (*acquired_event)(struct evsel *evsel, struct perf_sample *sample); /* it's used on CONFIG_LOCKDEP && CONFIG_LOCK_STAT */ int (*contended_event)(struct evsel *evsel, struct perf_sample *sample); /* it's used on CONFIG_LOCKDEP */ int (*release_event)(struct evsel *evsel, struct perf_sample *sample); /* it's used when CONFIG_LOCKDEP is off */ int (*contention_begin_event)(struct evsel *evsel, struct perf_sample *sample); /* it's used when CONFIG_LOCKDEP is off */ int (*contention_end_event)(struct evsel *evsel, struct perf_sample *sample); }; static struct lock_seq_stat *get_seq(struct thread_stat *ts, u64 addr) { struct lock_seq_stat *seq; list_for_each_entry(seq, &ts->seq_list, list) { if (seq->addr == addr) return seq; } seq = zalloc(sizeof(struct lock_seq_stat)); if (!seq) { pr_err("memory allocation failed\n"); return NULL; } seq->state = SEQ_STATE_UNINITIALIZED; seq->addr = addr; list_add(&seq->list, &ts->seq_list); return seq; } enum broken_state { BROKEN_ACQUIRE, BROKEN_ACQUIRED, BROKEN_CONTENDED, BROKEN_RELEASE, BROKEN_MAX, }; static int bad_hist[BROKEN_MAX]; enum acquire_flags { TRY_LOCK = 1, READ_LOCK = 2, }; static int report_lock_acquire_event(struct evsel *evsel, struct perf_sample *sample) { struct lock_stat *ls; struct thread_stat *ts; struct lock_seq_stat *seq; const char *name = evsel__strval(evsel, sample, "name"); u64 addr = evsel__intval(evsel, sample, "lockdep_addr"); int flag = evsel__intval(evsel, sample, "flags"); u64 key; switch (aggr_mode) { case LOCK_AGGR_ADDR: key = addr; break; case LOCK_AGGR_TASK: key = sample->tid; break; case LOCK_AGGR_CALLER: default: pr_err("Invalid aggregation mode: %d\n", aggr_mode); return -EINVAL; } ls = lock_stat_findnew(key, name, 0); if (!ls) return -ENOMEM; ts = thread_stat_findnew(sample->tid); if (!ts) return -ENOMEM; seq = get_seq(ts, addr); if (!seq) return -ENOMEM; switch (seq->state) { case SEQ_STATE_UNINITIALIZED: case SEQ_STATE_RELEASED: if (!flag) { seq->state = SEQ_STATE_ACQUIRING; } else { if (flag & TRY_LOCK) ls->nr_trylock++; if (flag & READ_LOCK) ls->nr_readlock++; seq->state = SEQ_STATE_READ_ACQUIRED; seq->read_count = 1; ls->nr_acquired++; } break; case SEQ_STATE_READ_ACQUIRED: if (flag & READ_LOCK) { seq->read_count++; ls->nr_acquired++; goto end; } else { goto broken; } break; case SEQ_STATE_ACQUIRED: case SEQ_STATE_ACQUIRING: case SEQ_STATE_CONTENDED: broken: /* broken lock sequence */ if (!ls->broken) { ls->broken = 1; bad_hist[BROKEN_ACQUIRE]++; } list_del_init(&seq->list); free(seq); goto end; default: BUG_ON("Unknown state of lock sequence found!\n"); break; } ls->nr_acquire++; seq->prev_event_time = sample->time; end: return 0; } static int report_lock_acquired_event(struct evsel *evsel, struct perf_sample *sample) { struct lock_stat *ls; struct thread_stat *ts; struct lock_seq_stat *seq; u64 contended_term; const char *name = evsel__strval(evsel, sample, "name"); u64 addr = evsel__intval(evsel, sample, "lockdep_addr"); u64 key; switch (aggr_mode) { case LOCK_AGGR_ADDR: key = addr; break; case LOCK_AGGR_TASK: key = sample->tid; break; case LOCK_AGGR_CALLER: default: pr_err("Invalid aggregation mode: %d\n", aggr_mode); return -EINVAL; } ls = lock_stat_findnew(key, name, 0); if (!ls) return -ENOMEM; ts = thread_stat_findnew(sample->tid); if (!ts) return -ENOMEM; seq = get_seq(ts, addr); if (!seq) return -ENOMEM; switch (seq->state) { case SEQ_STATE_UNINITIALIZED: /* orphan event, do nothing */ return 0; case SEQ_STATE_ACQUIRING: break; case SEQ_STATE_CONTENDED: contended_term = sample->time - seq->prev_event_time; ls->wait_time_total += contended_term; if (contended_term < ls->wait_time_min) ls->wait_time_min = contended_term; if (ls->wait_time_max < contended_term) ls->wait_time_max = contended_term; break; case SEQ_STATE_RELEASED: case SEQ_STATE_ACQUIRED: case SEQ_STATE_READ_ACQUIRED: /* broken lock sequence */ if (!ls->broken) { ls->broken = 1; bad_hist[BROKEN_ACQUIRED]++; } list_del_init(&seq->list); free(seq); goto end; default: BUG_ON("Unknown state of lock sequence found!\n"); break; } seq->state = SEQ_STATE_ACQUIRED; ls->nr_acquired++; ls->avg_wait_time = ls->nr_contended ? ls->wait_time_total/ls->nr_contended : 0; seq->prev_event_time = sample->time; end: return 0; } static int report_lock_contended_event(struct evsel *evsel, struct perf_sample *sample) { struct lock_stat *ls; struct thread_stat *ts; struct lock_seq_stat *seq; const char *name = evsel__strval(evsel, sample, "name"); u64 addr = evsel__intval(evsel, sample, "lockdep_addr"); u64 key; switch (aggr_mode) { case LOCK_AGGR_ADDR: key = addr; break; case LOCK_AGGR_TASK: key = sample->tid; break; case LOCK_AGGR_CALLER: default: pr_err("Invalid aggregation mode: %d\n", aggr_mode); return -EINVAL; } ls = lock_stat_findnew(key, name, 0); if (!ls) return -ENOMEM; ts = thread_stat_findnew(sample->tid); if (!ts) return -ENOMEM; seq = get_seq(ts, addr); if (!seq) return -ENOMEM; switch (seq->state) { case SEQ_STATE_UNINITIALIZED: /* orphan event, do nothing */ return 0; case SEQ_STATE_ACQUIRING: break; case SEQ_STATE_RELEASED: case SEQ_STATE_ACQUIRED: case SEQ_STATE_READ_ACQUIRED: case SEQ_STATE_CONTENDED: /* broken lock sequence */ if (!ls->broken) { ls->broken = 1; bad_hist[BROKEN_CONTENDED]++; } list_del_init(&seq->list); free(seq); goto end; default: BUG_ON("Unknown state of lock sequence found!\n"); break; } seq->state = SEQ_STATE_CONTENDED; ls->nr_contended++; ls->avg_wait_time = ls->wait_time_total/ls->nr_contended; seq->prev_event_time = sample->time; end: return 0; } static int report_lock_release_event(struct evsel *evsel, struct perf_sample *sample) { struct lock_stat *ls; struct thread_stat *ts; struct lock_seq_stat *seq; const char *name = evsel__strval(evsel, sample, "name"); u64 addr = evsel__intval(evsel, sample, "lockdep_addr"); u64 key; switch (aggr_mode) { case LOCK_AGGR_ADDR: key = addr; break; case LOCK_AGGR_TASK: key = sample->tid; break; case LOCK_AGGR_CALLER: default: pr_err("Invalid aggregation mode: %d\n", aggr_mode); return -EINVAL; } ls = lock_stat_findnew(key, name, 0); if (!ls) return -ENOMEM; ts = thread_stat_findnew(sample->tid); if (!ts) return -ENOMEM; seq = get_seq(ts, addr); if (!seq) return -ENOMEM; switch (seq->state) { case SEQ_STATE_UNINITIALIZED: goto end; case SEQ_STATE_ACQUIRED: break; case SEQ_STATE_READ_ACQUIRED: seq->read_count--; BUG_ON(seq->read_count < 0); if (seq->read_count) { ls->nr_release++; goto end; } break; case SEQ_STATE_ACQUIRING: case SEQ_STATE_CONTENDED: case SEQ_STATE_RELEASED: /* broken lock sequence */ if (!ls->broken) { ls->broken = 1; bad_hist[BROKEN_RELEASE]++; } goto free_seq; default: BUG_ON("Unknown state of lock sequence found!\n"); break; } ls->nr_release++; free_seq: list_del_init(&seq->list); free(seq); end: return 0; } bool is_lock_function(struct machine *machine, u64 addr) { if (!sched_text_start) { struct map *kmap; struct symbol *sym; sym = machine__find_kernel_symbol_by_name(machine, "__sched_text_start", &kmap); if (!sym) { /* to avoid retry */ sched_text_start = 1; return false; } sched_text_start = kmap->unmap_ip(kmap, sym->start); /* should not fail from here */ sym = machine__find_kernel_symbol_by_name(machine, "__sched_text_end", &kmap); sched_text_end = kmap->unmap_ip(kmap, sym->start); sym = machine__find_kernel_symbol_by_name(machine, "__lock_text_start", &kmap); lock_text_start = kmap->unmap_ip(kmap, sym->start); sym = machine__find_kernel_symbol_by_name(machine, "__lock_text_end", &kmap); lock_text_end = kmap->unmap_ip(kmap, sym->start); } /* failed to get kernel symbols */ if (sched_text_start == 1) return false; /* mutex and rwsem functions are in sched text section */ if (sched_text_start <= addr && addr < sched_text_end) return true; /* spinlock functions are in lock text section */ if (lock_text_start <= addr && addr < lock_text_end) return true; return false; } static int lock_contention_caller(struct evsel *evsel, struct perf_sample *sample, char *buf, int size) { struct thread *thread; struct callchain_cursor *cursor = &callchain_cursor; struct machine *machine = &session->machines.host; struct symbol *sym; int skip = 0; int ret; /* lock names will be replaced to task name later */ if (show_thread_stats) return -1; thread = machine__findnew_thread(machine, -1, sample->pid); if (thread == NULL) return -1; /* use caller function name from the callchain */ ret = thread__resolve_callchain(thread, cursor, evsel, sample, NULL, NULL, CONTENTION_STACK_DEPTH); if (ret != 0) { thread__put(thread); return -1; } callchain_cursor_commit(cursor); thread__put(thread); while (true) { struct callchain_cursor_node *node; node = callchain_cursor_current(cursor); if (node == NULL) break; /* skip first few entries - for lock functions */ if (++skip <= CONTENTION_STACK_SKIP) goto next; sym = node->ms.sym; if (sym && !is_lock_function(machine, node->ip)) { struct map *map = node->ms.map; u64 offset; offset = map->map_ip(map, node->ip) - sym->start; if (offset) scnprintf(buf, size, "%s+%#lx", sym->name, offset); else strlcpy(buf, sym->name, size); return 0; } next: callchain_cursor_advance(cursor); } return -1; } static u64 callchain_id(struct evsel *evsel, struct perf_sample *sample) { struct callchain_cursor *cursor = &callchain_cursor; struct machine *machine = &session->machines.host; struct thread *thread; u64 hash = 0; int skip = 0; int ret; thread = machine__findnew_thread(machine, -1, sample->pid); if (thread == NULL) return -1; /* use caller function name from the callchain */ ret = thread__resolve_callchain(thread, cursor, evsel, sample, NULL, NULL, CONTENTION_STACK_DEPTH); thread__put(thread); if (ret != 0) return -1; callchain_cursor_commit(cursor); while (true) { struct callchain_cursor_node *node; node = callchain_cursor_current(cursor); if (node == NULL) break; /* skip first few entries - for lock functions */ if (++skip <= CONTENTION_STACK_SKIP) goto next; if (node->ms.sym && is_lock_function(machine, node->ip)) goto next; hash ^= hash_long((unsigned long)node->ip, 64); next: callchain_cursor_advance(cursor); } return hash; } static int report_lock_contention_begin_event(struct evsel *evsel, struct perf_sample *sample) { struct lock_stat *ls; struct thread_stat *ts; struct lock_seq_stat *seq; u64 addr = evsel__intval(evsel, sample, "lock_addr"); u64 key; switch (aggr_mode) { case LOCK_AGGR_ADDR: key = addr; break; case LOCK_AGGR_TASK: key = sample->tid; break; case LOCK_AGGR_CALLER: key = callchain_id(evsel, sample); break; default: pr_err("Invalid aggregation mode: %d\n", aggr_mode); return -EINVAL; } ls = lock_stat_find(key); if (!ls) { char buf[128]; const char *caller = buf; unsigned int flags = evsel__intval(evsel, sample, "flags"); if (lock_contention_caller(evsel, sample, buf, sizeof(buf)) < 0) caller = "Unknown"; ls = lock_stat_findnew(key, caller, flags); if (!ls) return -ENOMEM; } ts = thread_stat_findnew(sample->tid); if (!ts) return -ENOMEM; seq = get_seq(ts, addr); if (!seq) return -ENOMEM; switch (seq->state) { case SEQ_STATE_UNINITIALIZED: case SEQ_STATE_ACQUIRED: break; case SEQ_STATE_CONTENDED: /* * It can have nested contention begin with mutex spinning, * then we would use the original contention begin event and * ignore the second one. */ goto end; case SEQ_STATE_ACQUIRING: case SEQ_STATE_READ_ACQUIRED: case SEQ_STATE_RELEASED: /* broken lock sequence */ if (!ls->broken) { ls->broken = 1; bad_hist[BROKEN_CONTENDED]++; } list_del_init(&seq->list); free(seq); goto end; default: BUG_ON("Unknown state of lock sequence found!\n"); break; } if (seq->state != SEQ_STATE_CONTENDED) { seq->state = SEQ_STATE_CONTENDED; seq->prev_event_time = sample->time; ls->nr_contended++; } end: return 0; } static int report_lock_contention_end_event(struct evsel *evsel, struct perf_sample *sample) { struct lock_stat *ls; struct thread_stat *ts; struct lock_seq_stat *seq; u64 contended_term; u64 addr = evsel__intval(evsel, sample, "lock_addr"); u64 key; switch (aggr_mode) { case LOCK_AGGR_ADDR: key = addr; break; case LOCK_AGGR_TASK: key = sample->tid; break; case LOCK_AGGR_CALLER: key = callchain_id(evsel, sample); break; default: pr_err("Invalid aggregation mode: %d\n", aggr_mode); return -EINVAL; } ls = lock_stat_find(key); if (!ls) return 0; ts = thread_stat_find(sample->tid); if (!ts) return 0; seq = get_seq(ts, addr); if (!seq) return -ENOMEM; switch (seq->state) { case SEQ_STATE_UNINITIALIZED: goto end; case SEQ_STATE_CONTENDED: contended_term = sample->time - seq->prev_event_time; ls->wait_time_total += contended_term; if (contended_term < ls->wait_time_min) ls->wait_time_min = contended_term; if (ls->wait_time_max < contended_term) ls->wait_time_max = contended_term; break; case SEQ_STATE_ACQUIRING: case SEQ_STATE_ACQUIRED: case SEQ_STATE_READ_ACQUIRED: case SEQ_STATE_RELEASED: /* broken lock sequence */ if (!ls->broken) { ls->broken = 1; bad_hist[BROKEN_ACQUIRED]++; } list_del_init(&seq->list); free(seq); goto end; default: BUG_ON("Unknown state of lock sequence found!\n"); break; } seq->state = SEQ_STATE_ACQUIRED; ls->nr_acquired++; ls->avg_wait_time = ls->wait_time_total/ls->nr_acquired; end: return 0; } /* lock oriented handlers */ /* TODO: handlers for CPU oriented, thread oriented */ static struct trace_lock_handler report_lock_ops = { .acquire_event = report_lock_acquire_event, .acquired_event = report_lock_acquired_event, .contended_event = report_lock_contended_event, .release_event = report_lock_release_event, .contention_begin_event = report_lock_contention_begin_event, .contention_end_event = report_lock_contention_end_event, }; static struct trace_lock_handler contention_lock_ops = { .contention_begin_event = report_lock_contention_begin_event, .contention_end_event = report_lock_contention_end_event, }; static struct trace_lock_handler *trace_handler; static int evsel__process_lock_acquire(struct evsel *evsel, struct perf_sample *sample) { if (trace_handler->acquire_event) return trace_handler->acquire_event(evsel, sample); return 0; } static int evsel__process_lock_acquired(struct evsel *evsel, struct perf_sample *sample) { if (trace_handler->acquired_event) return trace_handler->acquired_event(evsel, sample); return 0; } static int evsel__process_lock_contended(struct evsel *evsel, struct perf_sample *sample) { if (trace_handler->contended_event) return trace_handler->contended_event(evsel, sample); return 0; } static int evsel__process_lock_release(struct evsel *evsel, struct perf_sample *sample) { if (trace_handler->release_event) return trace_handler->release_event(evsel, sample); return 0; } static int evsel__process_contention_begin(struct evsel *evsel, struct perf_sample *sample) { if (trace_handler->contention_begin_event) return trace_handler->contention_begin_event(evsel, sample); return 0; } static int evsel__process_contention_end(struct evsel *evsel, struct perf_sample *sample) { if (trace_handler->contention_end_event) return trace_handler->contention_end_event(evsel, sample); return 0; } static void print_bad_events(int bad, int total) { /* Output for debug, this have to be removed */ int i; int broken = 0; const char *name[4] = { "acquire", "acquired", "contended", "release" }; for (i = 0; i < BROKEN_MAX; i++) broken += bad_hist[i]; if (broken == 0 && !verbose) return; pr_info("\n=== output for debug===\n\n"); pr_info("bad: %d, total: %d\n", bad, total); pr_info("bad rate: %.2f %%\n", (double)bad / (double)total * 100); pr_info("histogram of events caused bad sequence\n"); for (i = 0; i < BROKEN_MAX; i++) pr_info(" %10s: %d\n", name[i], bad_hist[i]); } /* TODO: various way to print, coloring, nano or milli sec */ static void print_result(void) { struct lock_stat *st; struct lock_key *key; char cut_name[20]; int bad, total; pr_info("%20s ", "Name"); list_for_each_entry(key, &lock_keys, list) pr_info("%*s ", key->len, key->header); pr_info("\n\n"); bad = total = 0; while ((st = pop_from_result())) { total++; if (st->broken) bad++; if (!st->nr_acquired) continue; bzero(cut_name, 20); if (strlen(st->name) < 20) { /* output raw name */ const char *name = st->name; if (show_thread_stats) { struct thread *t; /* st->addr contains tid of thread */ t = perf_session__findnew(session, st->addr); name = thread__comm_str(t); } pr_info("%20s ", name); } else { strncpy(cut_name, st->name, 16); cut_name[16] = '.'; cut_name[17] = '.'; cut_name[18] = '.'; cut_name[19] = '\0'; /* cut off name for saving output style */ pr_info("%20s ", cut_name); } list_for_each_entry(key, &lock_keys, list) { key->print(key, st); pr_info(" "); } pr_info("\n"); } print_bad_events(bad, total); } static bool info_threads, info_map; static void dump_threads(void) { struct thread_stat *st; struct rb_node *node; struct thread *t; pr_info("%10s: comm\n", "Thread ID"); node = rb_first(&thread_stats); while (node) { st = container_of(node, struct thread_stat, rb); t = perf_session__findnew(session, st->tid); pr_info("%10d: %s\n", st->tid, thread__comm_str(t)); node = rb_next(node); thread__put(t); } } static int compare_maps(struct lock_stat *a, struct lock_stat *b) { int ret; if (a->name && b->name) ret = strcmp(a->name, b->name); else ret = !!a->name - !!b->name; if (!ret) return a->addr < b->addr; else return ret < 0; } static void dump_map(void) { unsigned int i; struct lock_stat *st; pr_info("Address of instance: name of class\n"); for (i = 0; i < LOCKHASH_SIZE; i++) { hlist_for_each_entry(st, &lockhash_table[i], hash_entry) { insert_to_result(st, compare_maps); } } while ((st = pop_from_result())) pr_info(" %#llx: %s\n", (unsigned long long)st->addr, st->name); } static int dump_info(void) { int rc = 0; if (info_threads) dump_threads(); else if (info_map) dump_map(); else { rc = -1; pr_err("Unknown type of information\n"); } return rc; } typedef int (*tracepoint_handler)(struct evsel *evsel, struct perf_sample *sample); static int process_sample_event(struct perf_tool *tool __maybe_unused, union perf_event *event, struct perf_sample *sample, struct evsel *evsel, struct machine *machine) { int err = 0; struct thread *thread = machine__findnew_thread(machine, sample->pid, sample->tid); if (thread == NULL) { pr_debug("problem processing %d event, skipping it.\n", event->header.type); return -1; } if (evsel->handler != NULL) { tracepoint_handler f = evsel->handler; err = f(evsel, sample); } thread__put(thread); return err; } static void combine_result(void) { unsigned int i; struct lock_stat *st; if (!combine_locks) return; for (i = 0; i < LOCKHASH_SIZE; i++) { hlist_for_each_entry(st, &lockhash_table[i], hash_entry) { combine_lock_stats(st); } } } static void sort_result(void) { unsigned int i; struct lock_stat *st; for (i = 0; i < LOCKHASH_SIZE; i++) { hlist_for_each_entry(st, &lockhash_table[i], hash_entry) { insert_to_result(st, compare); } } } static const char *get_type_str(struct lock_stat *st) { static const struct { unsigned int flags; const char *name; } table[] = { { 0, "semaphore" }, { LCB_F_SPIN, "spinlock" }, { LCB_F_SPIN | LCB_F_READ, "rwlock:R" }, { LCB_F_SPIN | LCB_F_WRITE, "rwlock:W"}, { LCB_F_READ, "rwsem:R" }, { LCB_F_WRITE, "rwsem:W" }, { LCB_F_RT, "rtmutex" }, { LCB_F_RT | LCB_F_READ, "rwlock-rt:R" }, { LCB_F_RT | LCB_F_WRITE, "rwlock-rt:W"}, { LCB_F_PERCPU | LCB_F_READ, "pcpu-sem:R" }, { LCB_F_PERCPU | LCB_F_WRITE, "pcpu-sem:W" }, { LCB_F_MUTEX, "mutex" }, { LCB_F_MUTEX | LCB_F_SPIN, "mutex" }, }; for (unsigned int i = 0; i < ARRAY_SIZE(table); i++) { if (table[i].flags == st->flags) return table[i].name; } return "unknown"; } static void sort_contention_result(void) { sort_result(); } static void print_contention_result(void) { struct lock_stat *st; struct lock_key *key; int bad, total; list_for_each_entry(key, &lock_keys, list) pr_info("%*s ", key->len, key->header); if (show_thread_stats) pr_info(" %10s %s\n\n", "pid", "comm"); else pr_info(" %10s %s\n\n", "type", "caller"); bad = total = 0; if (use_bpf) bad = bad_hist[BROKEN_CONTENDED]; while ((st = pop_from_result())) { total += use_bpf ? st->nr_contended : 1; if (st->broken) bad++; list_for_each_entry(key, &lock_keys, list) { key->print(key, st); pr_info(" "); } if (show_thread_stats) { struct thread *t; int pid = st->addr; /* st->addr contains tid of thread */ t = perf_session__findnew(session, pid); pr_info(" %10d %s\n", pid, thread__comm_str(t)); continue; } pr_info(" %10s %s\n", get_type_str(st), st->name); } print_bad_events(bad, total); } static const struct evsel_str_handler lock_tracepoints[] = { { "lock:lock_acquire", evsel__process_lock_acquire, }, /* CONFIG_LOCKDEP */ { "lock:lock_acquired", evsel__process_lock_acquired, }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */ { "lock:lock_contended", evsel__process_lock_contended, }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */ { "lock:lock_release", evsel__process_lock_release, }, /* CONFIG_LOCKDEP */ }; static const struct evsel_str_handler contention_tracepoints[] = { { "lock:contention_begin", evsel__process_contention_begin, }, { "lock:contention_end", evsel__process_contention_end, }, }; static bool force; static int __cmd_report(bool display_info) { int err = -EINVAL; struct perf_tool eops = { .sample = process_sample_event, .comm = perf_event__process_comm, .mmap = perf_event__process_mmap, .namespaces = perf_event__process_namespaces, .ordered_events = true, }; struct perf_data data = { .path = input_name, .mode = PERF_DATA_MODE_READ, .force = force, }; session = perf_session__new(&data, &eops); if (IS_ERR(session)) { pr_err("Initializing perf session failed\n"); return PTR_ERR(session); } /* for lock function check */ symbol_conf.sort_by_name = true; symbol__init(&session->header.env); if (!perf_session__has_traces(session, "lock record")) goto out_delete; if (perf_session__set_tracepoints_handlers(session, lock_tracepoints)) { pr_err("Initializing perf session tracepoint handlers failed\n"); goto out_delete; } if (perf_session__set_tracepoints_handlers(session, contention_tracepoints)) { pr_err("Initializing perf session tracepoint handlers failed\n"); goto out_delete; } if (setup_output_field(false, output_fields)) goto out_delete; if (select_key(false)) goto out_delete; if (show_thread_stats) aggr_mode = LOCK_AGGR_TASK; err = perf_session__process_events(session); if (err) goto out_delete; setup_pager(); if (display_info) /* used for info subcommand */ err = dump_info(); else { combine_result(); sort_result(); print_result(); } out_delete: perf_session__delete(session); return err; } static void sighandler(int sig __maybe_unused) { } static int __cmd_contention(int argc, const char **argv) { int err = -EINVAL; struct perf_tool eops = { .sample = process_sample_event, .comm = perf_event__process_comm, .mmap = perf_event__process_mmap, .ordered_events = true, }; struct perf_data data = { .path = input_name, .mode = PERF_DATA_MODE_READ, .force = force, }; struct lock_contention con = { .target = &target, .result = &lockhash_table[0], .map_nr_entries = bpf_map_entries, }; session = perf_session__new(use_bpf ? NULL : &data, &eops); if (IS_ERR(session)) { pr_err("Initializing perf session failed\n"); return PTR_ERR(session); } /* for lock function check */ symbol_conf.sort_by_name = true; symbol__init(&session->header.env); if (use_bpf) { err = target__validate(&target); if (err) { char errbuf[512]; target__strerror(&target, err, errbuf, 512); pr_err("%s\n", errbuf); goto out_delete; } signal(SIGINT, sighandler); signal(SIGCHLD, sighandler); signal(SIGTERM, sighandler); con.machine = &session->machines.host; con.evlist = evlist__new(); if (con.evlist == NULL) { err = -ENOMEM; goto out_delete; } err = evlist__create_maps(con.evlist, &target); if (err < 0) goto out_delete; if (argc) { err = evlist__prepare_workload(con.evlist, &target, argv, false, NULL); if (err < 0) goto out_delete; } if (lock_contention_prepare(&con) < 0) { pr_err("lock contention BPF setup failed\n"); goto out_delete; } } else { if (!perf_session__has_traces(session, "lock record")) goto out_delete; if (!evlist__find_evsel_by_str(session->evlist, "lock:contention_begin")) { pr_err("lock contention evsel not found\n"); goto out_delete; } if (perf_session__set_tracepoints_handlers(session, contention_tracepoints)) { pr_err("Initializing perf session tracepoint handlers failed\n"); goto out_delete; } } if (setup_output_field(true, output_fields)) goto out_delete; if (select_key(true)) goto out_delete; if (show_thread_stats) aggr_mode = LOCK_AGGR_TASK; else aggr_mode = LOCK_AGGR_CALLER; if (use_bpf) { lock_contention_start(); if (argc) evlist__start_workload(con.evlist); /* wait for signal */ pause(); lock_contention_stop(); lock_contention_read(&con); /* abuse bad hist stats for lost entries */ bad_hist[BROKEN_CONTENDED] = con.lost; } else { err = perf_session__process_events(session); if (err) goto out_delete; } setup_pager(); sort_contention_result(); print_contention_result(); out_delete: evlist__delete(con.evlist); lock_contention_finish(); perf_session__delete(session); return err; } static int __cmd_record(int argc, const char **argv) { const char *record_args[] = { "record", "-R", "-m", "1024", "-c", "1", "--synth", "task", }; const char *callgraph_args[] = { "--call-graph", "fp," __stringify(CONTENTION_STACK_DEPTH), }; unsigned int rec_argc, i, j, ret; unsigned int nr_tracepoints; unsigned int nr_callgraph_args = 0; const char **rec_argv; bool has_lock_stat = true; for (i = 0; i < ARRAY_SIZE(lock_tracepoints); i++) { if (!is_valid_tracepoint(lock_tracepoints[i].name)) { pr_debug("tracepoint %s is not enabled. " "Are CONFIG_LOCKDEP and CONFIG_LOCK_STAT enabled?\n", lock_tracepoints[i].name); has_lock_stat = false; break; } } if (has_lock_stat) goto setup_args; for (i = 0; i < ARRAY_SIZE(contention_tracepoints); i++) { if (!is_valid_tracepoint(contention_tracepoints[i].name)) { pr_err("tracepoint %s is not enabled.\n", contention_tracepoints[i].name); return 1; } } nr_callgraph_args = ARRAY_SIZE(callgraph_args); setup_args: rec_argc = ARRAY_SIZE(record_args) + nr_callgraph_args + argc - 1; if (has_lock_stat) nr_tracepoints = ARRAY_SIZE(lock_tracepoints); else nr_tracepoints = ARRAY_SIZE(contention_tracepoints); /* factor of 2 is for -e in front of each tracepoint */ rec_argc += 2 * nr_tracepoints; rec_argv = calloc(rec_argc + 1, sizeof(char *)); if (!rec_argv) return -ENOMEM; for (i = 0; i < ARRAY_SIZE(record_args); i++) rec_argv[i] = strdup(record_args[i]); for (j = 0; j < nr_tracepoints; j++) { const char *ev_name; if (has_lock_stat) ev_name = strdup(lock_tracepoints[j].name); else ev_name = strdup(contention_tracepoints[j].name); if (!ev_name) return -ENOMEM; rec_argv[i++] = "-e"; rec_argv[i++] = ev_name; } for (j = 0; j < nr_callgraph_args; j++, i++) rec_argv[i] = callgraph_args[j]; for (j = 1; j < (unsigned int)argc; j++, i++) rec_argv[i] = argv[j]; BUG_ON(i != rec_argc); ret = cmd_record(i, rec_argv); free(rec_argv); return ret; } static int parse_map_entry(const struct option *opt, const char *str, int unset __maybe_unused) { unsigned long *len = (unsigned long *)opt->value; unsigned long val; char *endptr; errno = 0; val = strtoul(str, &endptr, 0); if (*endptr != '\0' || errno != 0) { pr_err("invalid BPF map length: %s\n", str); return -1; } *len = val; return 0; } int cmd_lock(int argc, const char **argv) { const struct option lock_options[] = { OPT_STRING('i', "input", &input_name, "file", "input file name"), OPT_INCR('v', "verbose", &verbose, "be more verbose (show symbol address, etc)"), OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace, "dump raw trace in ASCII"), OPT_BOOLEAN('f', "force", &force, "don't complain, do it"), OPT_STRING(0, "vmlinux", &symbol_conf.vmlinux_name, "file", "vmlinux pathname"), OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name, "file", "kallsyms pathname"), OPT_END() }; const struct option info_options[] = { OPT_BOOLEAN('t', "threads", &info_threads, "dump thread list in perf.data"), OPT_BOOLEAN('m', "map", &info_map, "map of lock instances (address:name table)"), OPT_PARENT(lock_options) }; const struct option report_options[] = { OPT_STRING('k', "key", &sort_key, "acquired", "key for sorting (acquired / contended / avg_wait / wait_total / wait_max / wait_min)"), OPT_STRING('F', "field", &output_fields, NULL, "output fields (acquired / contended / avg_wait / wait_total / wait_max / wait_min)"), /* TODO: type */ OPT_BOOLEAN('c', "combine-locks", &combine_locks, "combine locks in the same class"), OPT_BOOLEAN('t', "threads", &show_thread_stats, "show per-thread lock stats"), OPT_PARENT(lock_options) }; struct option contention_options[] = { OPT_STRING('k', "key", &sort_key, "wait_total", "key for sorting (contended / wait_total / wait_max / wait_min / avg_wait)"), OPT_STRING('F', "field", &output_fields, "contended,wait_total,wait_max,avg_wait", "output fields (contended / wait_total / wait_max / wait_min / avg_wait)"), OPT_BOOLEAN('t', "threads", &show_thread_stats, "show per-thread lock stats"), OPT_BOOLEAN('b', "use-bpf", &use_bpf, "use BPF program to collect lock contention stats"), OPT_BOOLEAN('a', "all-cpus", &target.system_wide, "System-wide collection from all CPUs"), OPT_STRING('C', "cpu", &target.cpu_list, "cpu", "List of cpus to monitor"), OPT_STRING('p', "pid", &target.pid, "pid", "Trace on existing process id"), OPT_STRING(0, "tid", &target.tid, "tid", "Trace on existing thread id (exclusive to --pid)"), OPT_CALLBACK(0, "map-nr-entries", &bpf_map_entries, "num", "Max number of BPF map entries", parse_map_entry), OPT_PARENT(lock_options) }; const char * const info_usage[] = { "perf lock info []", NULL }; const char *const lock_subcommands[] = { "record", "report", "script", "info", "contention", NULL }; const char *lock_usage[] = { NULL, NULL }; const char * const report_usage[] = { "perf lock report []", NULL }; const char * const contention_usage[] = { "perf lock contention []", NULL }; unsigned int i; int rc = 0; for (i = 0; i < LOCKHASH_SIZE; i++) INIT_HLIST_HEAD(lockhash_table + i); argc = parse_options_subcommand(argc, argv, lock_options, lock_subcommands, lock_usage, PARSE_OPT_STOP_AT_NON_OPTION); if (!argc) usage_with_options(lock_usage, lock_options); if (strlen(argv[0]) > 2 && strstarts("record", argv[0])) { return __cmd_record(argc, argv); } else if (strlen(argv[0]) > 2 && strstarts("report", argv[0])) { trace_handler = &report_lock_ops; if (argc) { argc = parse_options(argc, argv, report_options, report_usage, 0); if (argc) usage_with_options(report_usage, report_options); } rc = __cmd_report(false); } else if (!strcmp(argv[0], "script")) { /* Aliased to 'perf script' */ return cmd_script(argc, argv); } else if (!strcmp(argv[0], "info")) { if (argc) { argc = parse_options(argc, argv, info_options, info_usage, 0); if (argc) usage_with_options(info_usage, info_options); } /* recycling report_lock_ops */ trace_handler = &report_lock_ops; rc = __cmd_report(true); } else if (strlen(argv[0]) > 2 && strstarts("contention", argv[0])) { trace_handler = &contention_lock_ops; sort_key = "wait_total"; output_fields = "contended,wait_total,wait_max,avg_wait"; #ifndef HAVE_BPF_SKEL set_option_nobuild(contention_options, 'b', "use-bpf", "no BUILD_BPF_SKEL=1", false); #endif if (argc) { argc = parse_options(argc, argv, contention_options, contention_usage, 0); } rc = __cmd_contention(argc, argv); } else { usage_with_options(lock_usage, lock_options); } return rc; }