Some events (context-switch, sched:sched_switch) are losing the conversion of sample data associated with a thread. For example:
$ perf record -e sched:sched_switch -c 1 -a -- sleep 5 $ perf script <selected events shown> ls 30482 [000] 1379727.583037: sched:sched_switch: prev_comm=ls prev_pid=30482 ... ls 30482 [000] 1379727.586339: sched:sched_switch: prev_comm=ls prev_pid=30482 ... :30482 30482 [000] 1379727.589462: sched:sched_switch: prev_comm=ls prev_pid=30482 ... The last line lost the conversion from pid to comm. If you look at the events (perf script -D) you see why - a SAMPLE is generated after the EXIT: 0 1379727589449774 0x1540b0 [0x38]: PERF_RECORD_EXIT(30482:30482):(30482:30482) 0 1379727589462497 0x1540e8 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 30482/30482: 0xffffffff816416f1 period: 1 addr: 0 ... thread: :30482:30482 When perf processes the EXIT event the thread is moved to the dead_threads list. When the SAMPLE event is processed no thread exists for the pid so a new one is created by machine__findnew_thread. This patch addresses the problem by saving the exit time and checking the dead_threads list for the requested pid. If the time passed into machine_findnew_thread is non-0 the dead_threads list is walked looking for the pid. If the thread struct associated with the pid exited within 1usec of the time passed in the thread is considered a match and returned. If samples do not contain timestamps then sample->time will be 0 and the dead_threads list will not be checked. -1 can be used to force always checking the dead_threads list and returning a match. with this patch we get: ls 30482 [000] 1379727.583037: sched:sched_switch: prev_comm=ls prev_pid=30482 ... ls 30482 [000] 1379727.586339: sched:sched_switch: prev_comm=ls prev_pid=30482 ... ls 30482 [000] 1379727.589462: sched:sched_switch: prev_comm=ls prev_pid=30482 ... and 0 1379727589449774 0x1540b0 [0x38]: PERF_RECORD_EXIT(30482:30482):(30482:30482) 0 1379727589462497 0x1540e8 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 30482/30482: 0xffffffff816416f1 period: 1 addr: 0 ... thread: ls:30482 Signed-off-by: David Ahern <dsah...@gmail.com> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Jiri Olsa <jo...@redhat.com> Cc: Mike Galbraith <efa...@gmx.de> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephane Eranian <eran...@google.com> --- tools/perf/builtin-inject.c | 2 +- tools/perf/builtin-kmem.c | 3 ++- tools/perf/builtin-kvm.c | 3 ++- tools/perf/builtin-lock.c | 3 ++- tools/perf/builtin-sched.c | 17 +++++++------- tools/perf/builtin-script.c | 3 ++- tools/perf/builtin-trace.c | 9 +++++--- tools/perf/perf.h | 3 +++ tools/perf/tests/hists_link.c | 2 +- tools/perf/util/build-id.c | 11 ++++----- tools/perf/util/event.c | 11 +++++++-- tools/perf/util/machine.c | 49 ++++++++++++++++++++++++++++++++--------- tools/perf/util/machine.h | 6 +++-- tools/perf/util/session.c | 2 +- tools/perf/util/thread.h | 2 +- 15 files changed, 87 insertions(+), 39 deletions(-) diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index 84ad6ab..60f42c8 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -209,7 +209,7 @@ static int perf_event__inject_buildid(struct perf_tool *tool, cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK; - thread = machine__findnew_thread(machine, event->ip.pid); + thread = machine__findnew_thread(machine, event->ip.pid, sample->time); if (thread == NULL) { pr_err("problem processing %d event, skipping it.\n", event->header.type); diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c index 46878da..873647a 100644 --- a/tools/perf/builtin-kmem.c +++ b/tools/perf/builtin-kmem.c @@ -305,8 +305,9 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused, struct perf_evsel *evsel, struct machine *machine) { - struct thread *thread = machine__findnew_thread(machine, event->ip.pid); + struct thread *thread; + thread = machine__findnew_thread(machine, event->ip.pid, sample->time); if (thread == NULL) { pr_debug("problem processing %d event, skipping it.\n", event->header.type); diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index 533501e..c9572c2 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -688,10 +688,11 @@ static int process_sample_event(struct perf_tool *tool, struct perf_evsel *evsel, struct machine *machine) { - struct thread *thread = machine__findnew_thread(machine, sample->tid); + struct thread *thread; struct perf_kvm_stat *kvm = container_of(tool, struct perf_kvm_stat, tool); + thread = machine__findnew_thread(machine, sample->tid, sample->time); if (thread == NULL) { pr_debug("problem processing %d event, skipping it.\n", event->header.type); diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 4258300..1854eb9 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -805,8 +805,9 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused, struct perf_evsel *evsel, struct machine *machine) { - struct thread *thread = machine__findnew_thread(machine, sample->tid); + struct thread *thread; + thread = machine__findnew_thread(machine, sample->tid, sample->time); if (thread == NULL) { pr_debug("problem processing %d event, skipping it.\n", event->header.type); diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 2da2a6c..abdcdbc 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -934,8 +934,8 @@ static int latency_switch_event(struct perf_sched *sched, return -1; } - sched_out = machine__findnew_thread(machine, prev_pid); - sched_in = machine__findnew_thread(machine, next_pid); + sched_out = machine__findnew_thread(machine, prev_pid, timestamp); + sched_in = machine__findnew_thread(machine, next_pid, timestamp); out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid); if (!out_events) { @@ -978,7 +978,7 @@ static int latency_runtime_event(struct perf_sched *sched, { const u32 pid = perf_evsel__intval(evsel, sample, "pid"); const u64 runtime = perf_evsel__intval(evsel, sample, "runtime"); - struct thread *thread = machine__findnew_thread(machine, pid); + struct thread *thread = machine__findnew_thread(machine, pid, sample->time); struct work_atoms *atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid); u64 timestamp = sample->time; int cpu = sample->cpu; @@ -1016,7 +1016,7 @@ static int latency_wakeup_event(struct perf_sched *sched, if (!success) return 0; - wakee = machine__findnew_thread(machine, pid); + wakee = machine__findnew_thread(machine, pid, timestamp); atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid); if (!atoms) { if (thread_atoms_insert(sched, wakee)) @@ -1070,7 +1070,7 @@ static int latency_migrate_task_event(struct perf_sched *sched, if (sched->profile_cpu == -1) return 0; - migrant = machine__findnew_thread(machine, pid); + migrant = machine__findnew_thread(machine, pid, timestamp); atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid); if (!atoms) { if (thread_atoms_insert(sched, migrant)) @@ -1289,8 +1289,8 @@ static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel, return -1; } - sched_out = machine__findnew_thread(machine, prev_pid); - sched_in = machine__findnew_thread(machine, next_pid); + sched_out = machine__findnew_thread(machine, prev_pid, timestamp); + sched_in = machine__findnew_thread(machine, next_pid, timestamp); sched->curr_thread[this_cpu] = sched_in; @@ -1425,9 +1425,10 @@ static int perf_sched__process_tracepoint_sample(struct perf_tool *tool __maybe_ struct perf_evsel *evsel, struct machine *machine) { - struct thread *thread = machine__findnew_thread(machine, sample->tid); + struct thread *thread; int err = 0; + thread = machine__findnew_thread(machine, sample->tid, sample->time); if (thread == NULL) { pr_debug("problem processing %s event, skipping it.\n", perf_evsel__name(evsel)); diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 92d4658..2e07c70 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -479,8 +479,9 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused, struct machine *machine) { struct addr_location al; - struct thread *thread = machine__findnew_thread(machine, event->ip.tid); + struct thread *thread; + thread = machine__findnew_thread(machine, event->ip.tid, sample->time); if (thread == NULL) { pr_debug("problem processing %d event, skipping it.\n", event->header.type); diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index ab3ed4a..8f3e3d9 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -301,7 +301,8 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel, char *msg; void *args; size_t printed = 0; - struct thread *thread = machine__findnew_thread(&trace->host, sample->tid); + struct thread *thread = machine__findnew_thread(&trace->host, sample->tid, + sample->time); struct syscall *sc = trace__syscall_info(trace, evsel, sample); struct thread_trace *ttrace = thread__trace(thread); @@ -344,7 +345,8 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel, { int ret; u64 duration = 0; - struct thread *thread = machine__findnew_thread(&trace->host, sample->tid); + struct thread *thread = machine__findnew_thread(&trace->host, sample->tid, + sample->time); struct thread_trace *ttrace = thread__trace(thread); struct syscall *sc = trace__syscall_info(trace, evsel, sample); @@ -397,7 +399,8 @@ static int trace__sched_stat_runtime(struct trace *trace, struct perf_evsel *evs { u64 runtime = perf_evsel__intval(evsel, sample, "runtime"); double runtime_ms = (double)runtime / NSEC_PER_MSEC; - struct thread *thread = machine__findnew_thread(&trace->host, sample->tid); + struct thread *thread = machine__findnew_thread(&trace->host, sample->tid, + sample->time); struct thread_trace *ttrace = thread__trace(thread); if (ttrace == NULL) diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 32bd102..c98e9c9 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -125,6 +125,9 @@ #ifndef NSEC_PER_SEC # define NSEC_PER_SEC 1000000000ULL #endif +#ifndef USECS_PER_SEC +#define USECS_PER_SEC 1000000ULL +#endif static inline unsigned long long rdclock(void) { diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c index 89085a9..963d21e 100644 --- a/tools/perf/tests/hists_link.c +++ b/tools/perf/tests/hists_link.c @@ -88,7 +88,7 @@ static struct machine *setup_fake_machine(struct machines *machines) for (i = 0; i < ARRAY_SIZE(fake_threads); i++) { struct thread *thread; - thread = machine__findnew_thread(machine, fake_threads[i].pid); + thread = machine__findnew_thread(machine, fake_threads[i].pid, 0); if (thread == NULL) goto out; diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 5295625..c524906 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -18,14 +18,15 @@ int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused, union perf_event *event, - struct perf_sample *sample __maybe_unused, + struct perf_sample *sample, struct perf_evsel *evsel __maybe_unused, struct machine *machine) { struct addr_location al; u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK; - struct thread *thread = machine__findnew_thread(machine, event->ip.pid); + struct thread *thread; + thread = machine__findnew_thread(machine, event->ip.pid, sample->time); if (thread == NULL) { pr_err("problem processing %d event, skipping it.\n", event->header.type); @@ -43,12 +44,12 @@ int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused, static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused, union perf_event *event, - struct perf_sample *sample - __maybe_unused, + struct perf_sample *sample, struct machine *machine) { - struct thread *thread = machine__findnew_thread(machine, event->fork.tid); + struct thread *thread; + thread = machine__findnew_thread(machine, event->fork.tid, sample->time); dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid, event->fork.ppid, event->fork.ptid); diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 5cd13d7..4c15f82 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -552,9 +552,15 @@ int perf_event__process_fork(struct perf_tool *tool __maybe_unused, int perf_event__process_exit(struct perf_tool *tool __maybe_unused, union perf_event *event, - struct perf_sample *sample __maybe_unused, + struct perf_sample *sample, struct machine *machine) { + struct thread *thread; + + thread = machine__find_thread(machine, event->fork.tid, 0); + if (thread) + thread->t_exit = sample->time; + return machine__process_exit_event(machine, event); } @@ -677,8 +683,9 @@ int perf_event__preprocess_sample(const union perf_event *event, symbol_filter_t filter) { u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK; - struct thread *thread = machine__findnew_thread(machine, event->ip.pid); + struct thread *thread; + thread = machine__findnew_thread(machine, event->ip.pid, sample->time); if (thread == NULL) return -1; diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index b2ecad6..87211e3 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -30,7 +30,7 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid) return -ENOMEM; if (pid != HOST_KERNEL_ID) { - struct thread *thread = machine__findnew_thread(machine, pid); + struct thread *thread = machine__findnew_thread(machine, pid, 0); char comm[64]; if (thread == NULL) @@ -234,7 +234,7 @@ void machines__set_id_hdr_size(struct machines *machines, u16 id_hdr_size) } static struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, - bool create) + bool create, u64 sample_time) { struct rb_node **p = &machine->threads.rb_node; struct rb_node *parent = NULL; @@ -263,6 +263,26 @@ static struct thread *__machine__findnew_thread(struct machine *machine, pid_t p p = &(*p)->rb_right; } + + /* + * it is possible that we get a sample right after an exit event. + * e.g., scheduling events, the process exits generating an exit + * event and then is scheduled out (a sample event). + */ + + if (sample_time) { + list_for_each_entry(th, &machine->dead_threads, node) { + if (th->pid != pid) + continue; + + if ((sample_time == (u64) -1) || + ((th->t_exit < sample_time) && + ((sample_time - th->t_exit) < USECS_PER_SEC))) { + return th; + } + } + } + if (!create) return NULL; @@ -276,20 +296,23 @@ static struct thread *__machine__findnew_thread(struct machine *machine, pid_t p return th; } -struct thread *machine__findnew_thread(struct machine *machine, pid_t pid) +struct thread *machine__findnew_thread(struct machine *machine, pid_t pid, + u64 sample_time) { - return __machine__findnew_thread(machine, pid, true); + return __machine__findnew_thread(machine, pid, true, sample_time); } -struct thread *machine__find_thread(struct machine *machine, pid_t pid) +struct thread *machine__find_thread(struct machine *machine, pid_t pid, + u64 sample_time) { - return __machine__findnew_thread(machine, pid, false); + return __machine__findnew_thread(machine, pid, false, sample_time); } int machine__process_comm_event(struct machine *machine, union perf_event *event) { - struct thread *thread = machine__findnew_thread(machine, event->comm.tid); + struct thread *thread; + thread = machine__findnew_thread(machine, event->comm.tid, 0); if (dump_trace) perf_event__fprintf_comm(event, stdout); @@ -969,7 +992,7 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event return 0; } - thread = machine__findnew_thread(machine, event->mmap.pid); + thread = machine__findnew_thread(machine, event->mmap.pid, 0); if (thread == NULL) goto out_problem; @@ -996,9 +1019,11 @@ out_problem: int machine__process_fork_event(struct machine *machine, union perf_event *event) { - struct thread *thread = machine__findnew_thread(machine, event->fork.tid); - struct thread *parent = machine__findnew_thread(machine, event->fork.ptid); + struct thread *thread; + struct thread *parent; + thread = machine__findnew_thread(machine, event->fork.tid, 0); + parent = machine__findnew_thread(machine, event->fork.ptid, 0); if (dump_trace) perf_event__fprintf_task(event, stdout); @@ -1024,7 +1049,9 @@ static void machine__remove_thread(struct machine *machine, struct thread *th) int machine__process_exit_event(struct machine *machine, union perf_event *event) { - struct thread *thread = machine__find_thread(machine, event->fork.tid); + struct thread *thread; + + thread = machine__find_thread(machine, event->fork.tid, 0); if (dump_trace) perf_event__fprintf_task(event, stdout); diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index 7794068..30612f3 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -36,7 +36,8 @@ struct map *machine__kernel_map(struct machine *machine, enum map_type type) return machine->vmlinux_maps[type]; } -struct thread *machine__find_thread(struct machine *machine, pid_t pid); +struct thread *machine__find_thread(struct machine *machine, pid_t pid, + u64 sample_time); int machine__process_comm_event(struct machine *machine, union perf_event *event); int machine__process_exit_event(struct machine *machine, union perf_event *event); @@ -99,7 +100,8 @@ static inline bool machine__is_host(struct machine *machine) return machine ? machine->pid == HOST_KERNEL_ID : false; } -struct thread *machine__findnew_thread(struct machine *machine, pid_t pid); +struct thread *machine__findnew_thread(struct machine *machine, pid_t pid, + u64 sample_time); size_t machine__fprintf(struct machine *machine, FILE *fp); diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index cf1fe01..504ae0c 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -999,7 +999,7 @@ void perf_event_header__bswap(struct perf_event_header *self) struct thread *perf_session__findnew(struct perf_session *session, pid_t pid) { - return machine__findnew_thread(&session->machines.host, pid); + return machine__findnew_thread(&session->machines.host, pid, 0); } static struct thread *perf_session__register_idle_thread(struct perf_session *self) diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index 5ad2664..735b343 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -17,7 +17,7 @@ struct thread { bool comm_set; char *comm; int comm_len; - + u64 t_exit; void *priv; }; -- 1.7.10.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/