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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-04-02 11:12:01 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-06 09:30:45 +0200 |
| commit | c457810ab4a825161aec6ef71b581e1bc8febd1a (patch) | |
| tree | eccb22f8c868c4d8807657658027261eb97ed37f | |
| parent | 8a057d84912f36e53f970c4d177cb4bb6b2f9e08 (diff) | |
| download | lwn-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>
| -rw-r--r-- | include/linux/perf_counter.h | 3 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 10 |
2 files changed, 11 insertions, 2 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 06a6fba9f531..5428ba120d78 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -145,7 +145,7 @@ struct perf_counter_hw_event { __reserved_1 : 53; __u32 extra_config_len; - __u32 __reserved_4; + __u32 wakeup_events; /* wakeup every n events */ __u64 __reserved_2; __u64 __reserved_3; @@ -321,6 +321,7 @@ struct perf_mmap_data { int nr_pages; atomic_t wakeup; atomic_t head; + atomic_t events; struct perf_counter_mmap_page *user_page; void *data_pages[0]; }; 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(); } |