perf stat: Fix shadow stats for clock events

mainline inclusion
from mainline-5.0
commit 57ddf091
category: bugfix
bugzilla: 6781
CVE: NA

-------------------------------------------------

Commit 0aa802a7 ("perf stat: Get rid of extra clock display
function") introduced scale and unit for clock events. Thus,
perf_stat__update_shadow_stats() now saves scaled values of clock events
in msecs, instead of original nsecs. But while calculating values of
shadow stats we still consider clock event values in nsecs. This results
in a wrong shadow stat values. Ex,

  # ./perf stat -e task-clock,cycles ls
    <SNIP>
              2.60 msec task-clock:u    #    0.877 CPUs utilized
         2,430,564      cycles:u        # 1215282.000 GHz

Fix this by saving original nsec values for clock events in
perf_stat__update_shadow_stats(). After patch:

  # ./perf stat -e task-clock,cycles ls
    <SNIP>
              3.14 msec task-clock:u    #    0.839 CPUs utilized
         3,094,528      cycles:u        #    0.985 GHz
Suggested-by: NJiri Olsa <jolsa@redhat.com>
Reported-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: yuzhoujian@didichuxing.com
Fixes: 0aa802a7 ("perf stat: Get rid of extra clock display function")
Link: http://lkml.kernel.org/r/20181116042843.24067-1-ravi.bangoria@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
(cherry picked from commit 57ddf091)
Signed-off-by: NXie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

tools/perf/util/stat-shadow.c

@@ -209,11 +209,12 @@ void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 count,
 				    int cpu, struct runtime_stat *st)
 {
 	int ctx = evsel_context(counter);
+	u64 count_ns = count;
 
 	count *= counter->scale;
 
 	if (perf_evsel__is_clock(counter))
-		update_runtime_stat(st, STAT_NSECS, 0, cpu, count);
+		update_runtime_stat(st, STAT_NSECS, 0, cpu, count_ns);
 	else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
 		update_runtime_stat(st, STAT_CYCLES, ctx, cpu, count);
 	else if (perf_stat_evsel__is(counter, CYCLES_IN_TX))