Merge tag 'pci-v4.8-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

[cascardo/linux.git] / tools / perf / builtin-stat.c

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 0c16d20..3c7452b 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -331,7 +331,7 @@ static int read_counter(struct perf_evsel *counter)
        return 0;
 }
 
-static void read_counters(bool close_counters)
+static void read_counters(void)
 {
        struct perf_evsel *counter;
 
@@ -341,11 +341,6 @@ static void read_counters(bool close_counters)
 
                if (perf_stat_process_counter(&stat_config, counter))
                        pr_warning("failed to process counter %s\n", counter->name);
-
-               if (close_counters) {
-                       perf_evsel__close_fd(counter, perf_evsel__nr_cpus(counter),
-                                            thread_map__nr(evsel_list->threads));
-               }
        }
 }
 
@@ -353,7 +348,7 @@ static void process_interval(void)
 {
        struct timespec ts, rs;
 
-       read_counters(false);
+       read_counters();
 
        clock_gettime(CLOCK_MONOTONIC, &ts);
        diff_timespec(&rs, &ts, &ref_time);
@@ -380,6 +375,17 @@ static void enable_counters(void)
                perf_evlist__enable(evsel_list);
 }
 
+static void disable_counters(void)
+{
+       /*
+        * If we don't have tracee (attaching to task or cpu), counters may
+        * still be running. To get accurate group ratios, we must stop groups
+        * from counting before reading their constituent counters.
+        */
+       if (!target__none(&target))
+               perf_evlist__disable(evsel_list);
+}
+
 static volatile int workload_exec_errno;
 
 /*
@@ -657,11 +663,20 @@ try_again:
                }
        }
 
+       disable_counters();
+
        t1 = rdclock();
 
        update_stats(&walltime_nsecs_stats, t1 - t0);
 
-       read_counters(true);
+       /*
+        * Closing a group leader splits the group, and as we only disable
+        * group leaders, results in remaining events becoming enabled. To
+        * avoid arbitrary skew, we must read all counters before closing any
+        * group leaders.
+        */
+       read_counters();
+       perf_evlist__close(evsel_list);
 
        return WEXITSTATUS(status);
 }