From: Mike Galbraith Date: Sat, 10 Oct 2009 12:46:04 +0000 (+0200) Subject: perf sched: Add -C option to measure on a specific CPU X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=55ffb7a6bd45d0083ffb132381cb46964a4afe01;p=linux-beck.git perf sched: Add -C option to measure on a specific CPU To refresh, trying to sched record only one CPU results in bogus latencies as below. I fixed^Wmade it stop doing the bad thing today, by following task migration events properly. Before: marge:/root/tmp # taskset -c 1 perf sched record -C 0 -- sleep 10 marge:/root/tmp # perf sched lat ----------------------------------------------------------------------------------------- Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | ----------------------------------------------------------------------------------------- Xorg:4943 | 1.290 ms | 1 | avg: 1670.132 ms | max: 1670.132 ms | hald-addon-stor:3569 | 0.091 ms | 3 | avg: 658.609 ms | max: 1975.797 ms | hald-addon-stor:3573 | 0.209 ms | 4 | avg: 499.138 ms | max: 1990.565 ms | audispd:4270 | 0.012 ms | 1 | avg: 0.015 ms | max: 0.015 ms | .... marge:/root/tmp # perf sched trace|grep 'Xorg:4943' swapper-0 [000] 401.184013288: sched_stat_runtime: task: Xorg:4943 runtime: 1233188 [ns], vruntime: 19105169779 [ns] rt2870TimerQHan-4947 [000] 402.854140127: sched_stat_wait: task: Xorg:4943 wait: 580073 [ns] rt2870TimerQHan-4947 [000] 402.854141770: sched_migrate_task: task Xorg:4943 [140] from: 1 to: 0 rt2870TimerQHan-4947 [000] 402.854143854: sched_stat_wait: task: Xorg:4943 wait: 0 [ns] rt2870TimerQHan-4947 [000] 402.854145397: sched_switch: task rt2870TimerQHan:4947 [140] (D) ==> Xorg:4943 [140] Xorg-4943 [000] 402.854193133: sched_stat_runtime: task: Xorg:4943 runtime: 56546 [ns], vruntime: 11766332500 [ns] Xorg-4943 [000] 402.854196842: sched_switch: task Xorg:4943 [140] (S) ==> swapper:0 [140] After: marge:/root/tmp # taskset -c 1 perf sched record -C 0 -- sleep 10 marge:/root/tmp # perf sched lat ----------------------------------------------------------------------------------------- Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | ----------------------------------------------------------------------------------------- amarokapp:11150 | 271.297 ms | 878 | avg: 0.130 ms | max: 1.057 ms | konsole:5965 | 1.370 ms | 12 | avg: 0.092 ms | max: 0.855 ms | Xorg:4943 | 179.980 ms | 1109 | avg: 0.087 ms | max: 1.206 ms | hald-addon-stor:3574 | 0.212 ms | 9 | avg: 0.040 ms | max: 0.169 ms | hald-addon-stor:3570 | 0.223 ms | 9 | avg: 0.037 ms | max: 0.223 ms | klauncher:5864 | 0.550 ms | 8 | avg: 0.032 ms | max: 0.048 ms | The 'Maximum delay ms' results are now sane. Signed-off-by: Mike Galbraith LKML-Reference: Signed-off-by: Ingo Molnar --- diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 6b00529ce348..387a44234368 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -33,6 +33,8 @@ static u64 sample_type; static char default_sort_order[] = "avg, max, switch, runtime"; static char *sort_order = default_sort_order; +static int profile_cpu = -1; + static char *cwd; static int cwdlen; @@ -75,6 +77,7 @@ enum sched_event_type { SCHED_EVENT_RUN, SCHED_EVENT_SLEEP, SCHED_EVENT_WAKEUP, + SCHED_EVENT_MIGRATION, }; struct sched_atom { @@ -399,6 +402,8 @@ process_sched_event(struct task_desc *this_task __used, struct sched_atom *atom) ret = sem_post(atom->wait_sem); BUG_ON(ret); break; + case SCHED_EVENT_MIGRATION: + break; default: BUG_ON(1); } @@ -746,6 +751,22 @@ struct trace_fork_event { u32 child_pid; }; +struct trace_migrate_task_event { + u32 size; + + u16 common_type; + u8 common_flags; + u8 common_preempt_count; + u32 common_pid; + u32 common_tgid; + + char comm[16]; + u32 pid; + + u32 prio; + u32 cpu; +}; + struct trace_sched_handler { void (*switch_event)(struct trace_switch_event *, struct event *, @@ -770,6 +791,12 @@ struct trace_sched_handler { int cpu, u64 timestamp, struct thread *thread); + + void (*migrate_task_event)(struct trace_migrate_task_event *, + struct event *, + int cpu, + u64 timestamp, + struct thread *thread); }; @@ -1140,7 +1167,12 @@ latency_wakeup_event(struct trace_wakeup_event *wakeup_event, atom = list_entry(atoms->work_list.prev, struct work_atom, list); - if (atom->state != THREAD_SLEEPING) + /* + * You WILL be missing events if you've recorded only + * one CPU, or are only looking at only one, so don't + * make useless noise. + */ + if (profile_cpu == -1 && atom->state != THREAD_SLEEPING) nr_state_machine_bugs++; nr_timestamps++; @@ -1153,11 +1185,51 @@ latency_wakeup_event(struct trace_wakeup_event *wakeup_event, atom->wake_up_time = timestamp; } +static void +latency_migrate_task_event(struct trace_migrate_task_event *migrate_task_event, + struct event *__event __used, + int cpu __used, + u64 timestamp, + struct thread *thread __used) +{ + struct work_atoms *atoms; + struct work_atom *atom; + struct thread *migrant; + + /* + * Only need to worry about migration when profiling one CPU. + */ + if (profile_cpu == -1) + return; + + migrant = threads__findnew(migrate_task_event->pid, &threads, &last_match); + atoms = thread_atoms_search(&atom_root, migrant, &cmp_pid); + if (!atoms) { + thread_atoms_insert(migrant); + register_pid(migrant->pid, migrant->comm); + atoms = thread_atoms_search(&atom_root, migrant, &cmp_pid); + if (!atoms) + die("migration-event: Internal tree error"); + add_sched_out_event(atoms, 'R', timestamp); + } + + BUG_ON(list_empty(&atoms->work_list)); + + atom = list_entry(atoms->work_list.prev, struct work_atom, list); + atom->sched_in_time = atom->sched_out_time = atom->wake_up_time = timestamp; + + nr_timestamps++; + + if (atom->sched_out_time > timestamp) + nr_unordered_timestamps++; +} + static struct trace_sched_handler lat_ops = { .wakeup_event = latency_wakeup_event, .switch_event = latency_switch_event, .runtime_event = latency_runtime_event, .fork_event = latency_fork_event, + .migrate_task_event = latency_migrate_task_event, }; static void output_lat_thread(struct work_atoms *work_list) @@ -1517,6 +1589,26 @@ process_sched_exit_event(struct event *event, printf("sched_exit event %p\n", event); } +static void +process_sched_migrate_task_event(struct raw_event_sample *raw, + struct event *event, + int cpu __used, + u64 timestamp __used, + struct thread *thread __used) +{ + struct trace_migrate_task_event migrate_task_event; + + FILL_COMMON_FIELDS(migrate_task_event, event, raw->data); + + FILL_ARRAY(migrate_task_event, comm, event, raw->data); + FILL_FIELD(migrate_task_event, pid, event, raw->data); + FILL_FIELD(migrate_task_event, prio, event, raw->data); + FILL_FIELD(migrate_task_event, cpu, event, raw->data); + + if (trace_handler->migrate_task_event) + trace_handler->migrate_task_event(&migrate_task_event, event, cpu, timestamp, thread); +} + static void process_raw_event(event_t *raw_event __used, void *more_data, int cpu, u64 timestamp, struct thread *thread) @@ -1540,6 +1632,8 @@ process_raw_event(event_t *raw_event __used, void *more_data, process_sched_fork_event(raw, event, cpu, timestamp, thread); if (!strcmp(event->name, "sched_process_exit")) process_sched_exit_event(event, cpu, timestamp, thread); + if (!strcmp(event->name, "sched_migrate_task")) + process_sched_migrate_task_event(raw, event, cpu, timestamp, thread); } static int @@ -1589,6 +1683,9 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head) return -1; } + if (profile_cpu != -1 && profile_cpu != (int) cpu) + return 0; + process_raw_event(event, more_data, cpu, timestamp, thread); return 0; @@ -1771,6 +1868,8 @@ static const struct option latency_options[] = { "sort by key(s): runtime, switch, avg, max"), OPT_BOOLEAN('v', "verbose", &verbose, "be more verbose (show symbol address, etc)"), + OPT_INTEGER('C', "CPU", &profile_cpu, + "CPU to profile on"), OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace, "dump raw trace in ASCII"), OPT_END()