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perf sched: Add -C option to measure on a specific CPU

Browse source 
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 <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Mike Galbraith 2009-10-10 14:46:04 +02:00 committed by Ingo Molnar
parent 7e4ff9e3e8
commit 55ffb7a6bd
1 changed files with 100 additions and 1 deletions
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101
tools/perf/builtin-sched.c
View file

@ -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()