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>
This commit is contained in:
David Ahern 2013-08-02 14:05:40 -06:00 committed by Arnaldo Carvalho de Melo
parent 42ee8c61cb
commit ffe4f3c0d1
2 changed files with 15 additions and 0 deletions

View file

@ -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)

View file

@ -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