From c66de4a5be7913247bd83d79168f8e4420c9cfbc Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 5 May 2009 17:50:22 +0200 Subject: 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 Signed-off-by: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <20090505155436.925084300@chello.nl> Signed-off-by: Ingo Molnar --- include/linux/perf_counter.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index a356fa69796c..17b63105f2aa 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]; }; -- cgit v1.2.3