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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-09-17 19:01:10 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-17 22:08:26 +0200 |
| commit | 2667de81f3256c944b06abdf2c56c2f192fcb724 (patch) | |
| tree | d642156cfe0c52d2fb7ec1de4a2060018c8e3f8d /include/linux/perf_counter.h | |
| parent | 850bc73ffcc99cddfb52bc23217c60810c508853 (diff) | |
| download | lwn-2667de81f3256c944b06abdf2c56c2f192fcb724.tar.gz lwn-2667de81f3256c944b06abdf2c56c2f192fcb724.zip | |
perf_counter: Allow for a wakeup watermark
Currently we wake the mmap() consumer once every PAGE_SIZE of data
and/or once event wakeup_events when specified.
For high speed sampling this results in too many wakeups wrt. the
buffer size, hence change this.
We move the default wakeup limit to 1/4-th the buffer size, and
provide for means to manually specify this limit.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/perf_counter.h')
| -rw-r--r-- | include/linux/perf_counter.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 972f90d7a32f..6c1ef72ea501 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -199,10 +199,14 @@ struct perf_counter_attr { inherit_stat : 1, /* per task counts */ enable_on_exec : 1, /* next exec enables */ task : 1, /* trace fork/exit */ + watermark : 1, /* wakeup_watermark */ - __reserved_1 : 50; + __reserved_1 : 49; - __u32 wakeup_events; /* wakeup every n events */ + union { + __u32 wakeup_events; /* wakeup every n events */ + __u32 wakeup_watermark; /* bytes before wakeup */ + }; __u32 __reserved_2; __u64 __reserved_3; @@ -521,6 +525,8 @@ struct perf_mmap_data { atomic_t wakeup; /* needs a wakeup */ atomic_t lost; /* nr records lost */ + long watermark; /* wakeup watermark */ + struct perf_counter_mmap_page *user_page; void *data_pages[0]; }; |