diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2009-11-23 15:00:36 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-23 15:22:19 +0100 |
| commit | acd1d7c1f8f3d848a3c5327dc09f8c1efb971678 (patch) | |
| tree | 88ec283110f78cf803c71a3d1d919a422f2f13c5 /kernel/hw_breakpoint.c | |
| parent | 4ed7c92d68a5387ba5f7030dc76eab03558e27f5 (diff) | |
perf_events: Restore sanity to scaling land
It is quite possible to call update_event_times() on a context
that isn't actually running and thereby confuse the thing.
perf stat was reporting !100% scale values for software counters
(2e2af50b perf_events: Disable events when we detach them,
solved the worst of that, but there was still some left).
The thing that happens is that because we are not self-reaping
(we have a caring parent) there is a time between the last
schedule (out) and having do_exit() called which will detach the
events.
This period would be accounted as enabled,!running because the
event->state==INACTIVE, even though !event->ctx->is_active.
Similar issues could have been observed by calling read() on a
event while the attached task was not scheduled in.
Solve this by teaching update_event_times() about
ctx->is_active.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1258984836.4531.480.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/hw_breakpoint.c')
0 files changed, 0 insertions, 0 deletions