sched: Deliver sched_switch events to the current task
authorAndrew Vagin <avagin@openvz.org>
Thu, 12 Jul 2012 10:14:29 +0000 (14:14 +0400)
committerIngo Molnar <mingo@kernel.org>
Thu, 26 Jul 2012 10:23:10 +0000 (12:23 +0200)
commit895dd92c032e1604aa0d7afaef7716e058343b67
tree8662091be28c24a44287fc43790cf92547499a83
parent045e7e6047037d93824d265cc30c33eb631f8883
sched: Deliver sched_switch events to the current task

Otherwise they can't be filtered for a defined task:

  perf record -e sched:sched_switch ./foo

This command doesn't report any events without this patch.

I think it isn't a security concern if someone knows who will
be executed next - this can already be observed by polling /proc
state. By default perf is disabled for non-root users in any case.

I need these events for profiling sleep times.  sched_switch is used for
getting callchains and sched_stat_* is used for getting time periods.
These events are combined in user space, then it can be analyzed by
perf tools.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arun Sharma <asharma@fb.com>
Link: http://lkml.kernel.org/r/1342088069-1005148-1-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/sched/core.c