Sample, record, parse and print the CPU field - it had all zeroes before.

Before (watch the second column, the CPU values):

            perf-32685 [000]     0.000000: sched_wakeup_new: task perf:32686 [120] success=1 [011]
            perf-32685 [000]     0.000000: sched_migrate_task: task perf:32685 [120] from: 1  to: 11
            perf-32685 [000]     0.000000: sched_process_fork: parent perf:32685  child perf:32686
            true-32686 [000]     0.000000: sched_wakeup: task migration/11:25 [0] success=1 [011]
            true-32686 [000]     0.000000: sched_wakeup: task distccd:12793 [125] success=1 [015]
            true-32686 [000]     0.000000: sched_wakeup: task distccd:12793 [125] success=1 [015]
            perf-32685 [000]     0.000000: sched_switch: task perf:32685 [120] (S) ==> swapper:0 [140]
            true-32686 [000]     0.000000: sched_switch: task perf:32686 [120] (R) ==> migration/11:25 [0]
            true-32686 [000]     0.000000: sched_switch: task perf:32686 [120] (R) ==> distccd:12793 [125]
            true-32686 [000]     0.000000: sched_switch: task true:32686 [120] (R) ==> distccd:12793 [125]
            true-32686 [000]     0.000000: sched_process_exit: task true:32686 [120]
            true-32686 [000]     0.000000: sched_stat_wait: task: distccd:12793 wait: 6767985949080 [ns]
            true-32686 [000]     0.000000: sched_stat_wait: task: distccd:12793 wait: 6767986139446 [ns]
            true-32686 [000]     0.000000: sched_stat_sleep: task: distccd:12793 sleep: 132844 [ns]
            true-32686 [000]     0.000000: sched_stat_sleep: task: distccd:12793 sleep: 131724 [ns]

After:

            perf-32685 [001]     0.000000: sched_wakeup_new: task perf:32686 [120] success=1 [011]
            perf-32685 [001]     0.000000: sched_migrate_task: task perf:32685 [120] from: 1  to: 11
            perf-32685 [001]     0.000000: sched_process_fork: parent perf:32685  child perf:32686
            true-32686 [011]     0.000000: sched_wakeup: task migration/11:25 [0] success=1 [011]
            true-32686 [015]     0.000000: sched_wakeup: task distccd:12793 [125] success=1 [015]
            true-32686 [015]     0.000000: sched_wakeup: task distccd:12793 [125] success=1 [015]
            perf-32685 [001]     0.000000: sched_switch: task perf:32685 [120] (S) ==> swapper:0 [140]
            true-32686 [011]     0.000000: sched_switch: task perf:32686 [120] (R) ==> migration/11:25 [0]
            true-32686 [015]     0.000000: sched_switch: task perf:32686 [120] (R) ==> distccd:12793 [125]
            true-32686 [015]     0.000000: sched_switch: task true:32686 [120] (R) ==> distccd:12793 [125]
            true-32686 [015]     0.000000: sched_process_exit: task true:32686 [120]
            true-32686 [015]     0.000000: sched_stat_wait: task: distccd:12793 wait: 6767985949080 [ns]
            true-32686 [015]     0.000000: sched_stat_wait: task: distccd:12793 wait: 6767986139446 [ns]
            true-32686 [015]     0.000000: sched_stat_sleep: task: distccd:12793 sleep: 132844 [ns]
            true-32686 [015]     0.000000: sched_stat_sleep: task: distccd:12793 sleep: 131724 [ns]

So we can now see how this workload migrated between CPUs.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>