diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index dcedfe00f04d..749246817aed 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -1411,6 +1411,13 @@ int cmd_report(int argc, const char **argv) if (ret < 0) goto exit; + /* + * tasks_mode require access to exited threads to list those that are in + * the data file. Off-cpu events are synthesized after other events and + * reference exited threads. + */ + symbol_conf.keep_exited_threads = true; + annotation_options__init(&report.annotation_opts); ret = perf_config(report__config, &report); diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index e6a8d758f6fe..7c6874804660 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2158,9 +2158,13 @@ int machine__process_exit_event(struct machine *machine, union perf_event *event if (dump_trace) perf_event__fprintf_task(event, stdout); - if (thread != NULL) - thread__put(thread); - + if (thread != NULL) { + if (symbol_conf.keep_exited_threads) + thread__set_exited(thread, /*exited=*/true); + else + machine__remove_thread(machine, thread); + } + thread__put(thread); return 0; } diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 1e9aa8ed15b6..c6afba7ab1a5 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -115,6 +115,11 @@ static int perf_session__open(struct perf_session *session, int repipe_fd) return -1; } + if (perf_header__has_feat(&session->header, HEADER_AUXTRACE)) { + /* Auxiliary events may reference exited threads, hold onto dead ones. */ + symbol_conf.keep_exited_threads = true; + } + if (perf_data__is_pipe(data)) return 0; diff --git a/tools/perf/util/symbol_conf.h b/tools/perf/util/symbol_conf.h index 2b2fb9e224b0..6040286e07a6 100644 --- a/tools/perf/util/symbol_conf.h +++ b/tools/perf/util/symbol_conf.h @@ -43,7 +43,8 @@ struct symbol_conf { disable_add2line_warn, buildid_mmap2, guest_code, - lazy_load_kernel_maps; + lazy_load_kernel_maps, + keep_exited_threads; const char *vmlinux_name, *kallsyms_name, *source_prefix, diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index e79225a0ea46..0df775b5c110 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -36,13 +36,22 @@ struct thread_rb_node { }; DECLARE_RC_STRUCT(thread) { + /** @maps: mmaps associated with this thread. */ struct maps *maps; pid_t pid_; /* Not all tools update this */ + /** @tid: thread ID number unique to a machine. */ pid_t tid; + /** @ppid: parent process of the process this thread belongs to. */ pid_t ppid; int cpu; int guest_cpu; /* For QEMU thread */ refcount_t refcnt; + /** + * @exited: Has the thread had an exit event. Such threads are usually + * removed from the machine's threads but some events/tools require + * access to dead threads. + */ + bool exited; bool comm_set; int comm_len; struct list_head namespaces_list; @@ -189,6 +198,11 @@ static inline refcount_t *thread__refcnt(struct thread *thread) return &RC_CHK_ACCESS(thread)->refcnt; } +static inline void thread__set_exited(struct thread *thread, bool exited) +{ + RC_CHK_ACCESS(thread)->exited = exited; +} + static inline bool thread__comm_set(const struct thread *thread) { return RC_CHK_ACCESS(thread)->comm_set;