perf stat: Move stats related code to util/stat.c
Then, the code can be shared between kvm events and perf stat.
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
[ Dong Hao <haodong@linux.vnet.ibm.com>: rebase it on acme's git tree ]
Signed-off-by: Dong Hao <haodong@linux.vnet.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1347870675-31495-3-git-send-email-haodong@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
new file mode 100644
index 0000000..588367c3
--- /dev/null
+++ b/tools/perf/util/stat.h
@@ -0,0 +1,16 @@
+#ifndef __PERF_STATS_H
+#define __PERF_STATS_H
+
+#include "types.h"
+
+struct stats
+{
+ double n, mean, M2;
+};
+
+void update_stats(struct stats *stats, u64 val);
+double avg_stats(struct stats *stats);
+double stddev_stats(struct stats *stats);
+double rel_stddev_stats(double stddev, double avg);
+
+#endif
