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Example output: $ sudo ~/linux/tools/perf/perf lock con -abvo -Y mutex-spin -E3 perf bench sched pipe ... contended total wait max wait avg wait type caller 171 1.55 ms 20.26 us 9.06 us mutex pipe_read+0x57 0xffffffffac6318e7 pipe_read+0x57 0xffffffffac623862 vfs_read+0x332 0xffffffffac62434b ksys_read+0xbb 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 36 193.71 us 15.27 us 5.38 us mutex pipe_write+0x50 0xffffffffac631ee0 pipe_write+0x50 0xffffffffac6241db vfs_write+0x3bb 0xffffffffac6244ab ksys_write+0xbb 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 4 51.22 us 16.47 us 12.80 us mutex do_epoll_wait+0x24d 0xffffffffac691f0d do_epoll_wait+0x24d 0xffffffffac69249b do_epoll_pwait.part.0+0xb 0xffffffffac693ba5 __x64_sys_epoll_pwait+0x95 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 === owner stack trace === 3 31.24 us 15.27 us 10.41 us mutex pipe_read+0x348 0xffffffffac631bd8 pipe_read+0x348 0xffffffffac623862 vfs_read+0x332 0xffffffffac62434b ksys_read+0xbb 0xfffffffface604b2 do_syscall_64+0x82 0xffffffffad00012f entry_SYSCALL_64_after_hwframe+0x76 ... Signed-off-by: Chun-Tse Shao --- tools/perf/builtin-lock.c | 20 ++++++++++++- tools/perf/util/bpf_lock_contention.c | 41 +++++++++++++++++++++++++++ tools/perf/util/lock-contention.h | 2 ++ 3 files changed, 62 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index f9b7620444c0..0dfec175b25b 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -42,6 +42,7 @@ #include #include #include +#include static struct perf_session *session; static struct target target; @@ -1926,6 +1927,23 @@ static void print_contention_result(struct lock_contention *con) break; } + if (con->owner && con->save_callstack) { + struct rb_root root = RB_ROOT; + + + if (symbol_conf.field_sep) + fprintf(lock_output, "# owner stack trace:\n"); + else + fprintf(lock_output, "\n=== owner stack trace ===\n\n"); + while ((st = pop_owner_stack_trace(con))) + insert_to(&root, st, compare); + + while ((st = pop_from(&root))) { + print_lock_stat(con, st); + zfree(st); + } + } + if (print_nr_entries) { /* update the total/bad stats */ while ((st = pop_from_result())) { @@ -2071,7 +2089,7 @@ static int check_lock_contention_options(const struct option *options, } } - if (show_lock_owner) + if (show_lock_owner && !verbose) show_thread_stats = true; return 0; diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c index c9c58f243ceb..a63d5ffac386 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -414,6 +414,47 @@ static const char *lock_contention_get_name(struct lock_contention *con, return name_buf; } +struct lock_stat *pop_owner_stack_trace(struct lock_contention *con) +{ + int fd; + u64 *stack_trace; + struct contention_data data = {}; + size_t stack_size = con->max_stack * sizeof(*stack_trace); + struct lock_stat *st; + char name[KSYM_NAME_LEN]; + + fd = bpf_map__fd(skel->maps.owner_lock_stat); + + stack_trace = zalloc(stack_size); + if (stack_trace == NULL) + return NULL; + + if (bpf_map_get_next_key(fd, NULL, stack_trace)) + return NULL; + + bpf_map_lookup_elem(fd, stack_trace, &data); + st = zalloc(sizeof(struct lock_stat)); + + strcpy(name, stack_trace[0] ? lock_contention_get_name(con, NULL, + stack_trace, 0) : + "unknown"); + + st->name = strdup(name); + st->flags = data.flags; + st->nr_contended = data.count; + st->wait_time_total = data.total_time; + st->wait_time_max = data.max_time; + st->wait_time_min = data.min_time; + st->callstack = memdup(stack_trace, stack_size); + + if (data.count) + st->avg_wait_time = data.total_time / data.count; + + bpf_map_delete_elem(fd, stack_trace); + free(stack_trace); + + return st; +} int lock_contention_read(struct lock_contention *con) { int fd, stack, err = 0; diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h index 1a7248ff3889..83b400a36137 100644 --- a/tools/perf/util/lock-contention.h +++ b/tools/perf/util/lock-contention.h @@ -156,6 +156,8 @@ int lock_contention_stop(void); int lock_contention_read(struct lock_contention *con); int lock_contention_finish(struct lock_contention *con); +struct lock_stat *pop_owner_stack_trace(struct lock_contention *con); + #else /* !HAVE_BPF_SKEL */ static inline int lock_contention_prepare(struct lock_contention *con __maybe_unused)