perf stats: Add max and min stats

Need an initialization function to set min to -1 to
differentiate from an actual min of 0.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1375473947-64285-3-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 7c59c28afcc5..6506b3dfb605 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -10,6 +10,12 @@ void update_stats(struct stats *stats, u64 val)
         delta = val - stats->mean;
         stats->mean += delta / stats->n;
         stats->M2 += delta*(val - stats->mean);
+
+        if (val > stats->max)
+                stats->max = val;
+
+        if (val < stats->min)
+                stats->min = val;
 }
 
 double avg_stats(struct stats *stats)