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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-04-02 11:12:01 +0200
committerIngo Molnar <mingo@elte.hu>2009-04-06 09:30:45 +0200
commitc457810ab4a825161aec6ef71b581e1bc8febd1a (patch)
treeeccb22f8c868c4d8807657658027261eb97ed37f /kernel/perf_counter.c
parent8a057d84912f36e53f970c4d177cb4bb6b2f9e08 (diff)
downloadlwn-c457810ab4a825161aec6ef71b581e1bc8febd1a.tar.gz
lwn-c457810ab4a825161aec6ef71b581e1bc8febd1a.zip
perf_counter: per event wakeups
By request, provide a way to request a wakeup every 'n' events instead of every page of output. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Orig-LKML-Reference: <20090402091319.323309784@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_counter.c')
-rw-r--r--kernel/perf_counter.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 995063df910f..9bcab10e735d 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1760,7 +1760,15 @@ static void perf_output_copy(struct perf_output_handle *handle,
static void perf_output_end(struct perf_output_handle *handle)
{
- if (handle->wakeup)
+ int wakeup_events = handle->counter->hw_event.wakeup_events;
+
+ if (wakeup_events) {
+ int events = atomic_inc_return(&handle->data->events);
+ if (events >= wakeup_events) {
+ atomic_sub(wakeup_events, &handle->data->events);
+ __perf_output_wakeup(handle);
+ }
+ } else if (handle->wakeup)
__perf_output_wakeup(handle);
rcu_read_unlock();
}