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>

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 7c59c28afcc524467f6d1824dccc2442e540c6a6..6506b3dfb6059f71aa6c345df21fcbc16e651604 100644 (file)
--- 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)

diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 588367c3c767f2fd6ff7f3f317986756174a2b3c..ae8ccd7227cfa2d3f0a2e74ab06efab814ac3bfd 100644 (file)
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -6,6 +6,7 @@
 struct stats
 {
        double n, mean, M2;
+       u64 max, min;
 };
 
 void update_stats(struct stats *stats, u64 val);
@@ -13,4 +14,12 @@ double avg_stats(struct stats *stats);
 double stddev_stats(struct stats *stats);
 double rel_stddev_stats(double stddev, double avg);
 
+static inline void init_stats(struct stats *stats)
+{
+       stats->n    = 0.0;
+       stats->mean = 0.0;
+       stats->M2   = 0.0;
+       stats->min  = (u64) -1;
+       stats->max  = 0;
+}
 #endif