From 8e3747c13c39246c7e46def7cf495d9d21d4c5f9 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 2 Jun 2009 16:16:02 +0200 Subject: perf_counter: Change data head from u32 to u64 Since some people worried that 4G might not be a large enough as an mmap data window, extend it to 64 bit for capable platforms. Reported-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/perf_counter.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux/perf_counter.h') diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index cef9931793f..c046f7d97cf 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -212,7 +212,7 @@ struct perf_counter_mmap_page { * User-space reading this value should issue an rmb(), on SMP capable * platforms, after reading this value -- see perf_counter_wakeup(). */ - __u32 data_head; /* head in the data section */ + __u64 data_head; /* head in the data section */ }; #define PERF_EVENT_MISC_CPUMODE_MASK (3 << 0) @@ -397,10 +397,11 @@ struct perf_mmap_data { int nr_locked; /* nr pages mlocked */ atomic_t poll; /* POLL_ for wakeups */ - atomic_t head; /* write position */ atomic_t events; /* event limit */ - atomic_t done_head; /* completed head */ + atomic_long_t head; /* write position */ + atomic_long_t done_head; /* completed head */ + atomic_t lock; /* concurrent writes */ atomic_t wakeup; /* needs a wakeup */ -- cgit v1.2.3