diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-05 17:50:22 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-05 20:18:30 +0200 |
| commit | c66de4a5be7913247bd83d79168f8e4420c9cfbc (patch) | |
| tree | c671172166d94be75ad9d6df1fdafa0c006c4609 /include/linux | |
| parent | 066d7dea32c9bffe6decc0abe465627656cdd84e (diff) | |
perf_counter: uncouple data_head updates from wakeups
Keep data_head up-to-date irrespective of notifications. This fixes
the case where you disable a counter and don't get a notification for
the last few pending events, and it also allows polling usage.
[ Impact: increase precision of perfcounter mmap-ed fields ]
Suggested-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090505155436.925084300@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/perf_counter.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index a356fa69796..17b63105f2a 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -362,9 +362,11 @@ struct perf_mmap_data { atomic_t head; /* write position */ atomic_t events; /* event limit */ - atomic_t wakeup_head; /* completed head */ + atomic_t done_head; /* completed head */ atomic_t lock; /* concurrent writes */ + atomic_t wakeup; /* needs a wakeup */ + struct perf_counter_mmap_page *user_page; void *data_pages[0]; }; |