perf evlist: Fix grouping of multiple events

The __perf_evsel__open routing was grouping just the threads for that
specific events per cpu when we want to group all threads in all events
to the first fd opened on that cpu.

So pass the xyarray with the first event, where the other events will be
able to get that first per cpu fd.

At some point top and record will switch to using perf_evlist__open that
takes care of this detail and probably will also handle the fallback
from hw to soft counters, etc.

Reported-by: Deng-Cheng Zhu <dczhu@mips.com>
Tested-by: Deng-Cheng Zhu <dczhu@mips.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ebm34rh098i9y9v4cytfdp0x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 14 insertions, 6 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7ce65f52415e..7d98676808d8 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -278,9 +278,14 @@ struct stats			runtime_itlb_cache_stats[MAX_NR_CPUS];
 struct stats                    runtime_dtlb_cache_stats[MAX_NR_CPUS];
 struct stats                    walltime_nsecs_stats;
 
-static int create_perf_stat_counter(struct perf_evsel *evsel)
+static int create_perf_stat_counter(struct perf_evsel *evsel,
+                                    struct perf_evsel *first)
 {
         struct perf_event_attr *attr = &evsel->attr;
+        struct xyarray *group_fd = NULL;
+
+        if (group && evsel != first)
+                group_fd = first->fd;
 
         if (scale)
                 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
@@ -289,14 +294,15 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
         attr->inherit = !no_inherit;
 
         if (system_wide)
-                return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, group);
-
+                return perf_evsel__open_per_cpu(evsel, evsel_list->cpus,
+                                                group, group_fd);
         if (target_pid == -1 && target_tid == -1) {
                 attr->disabled = 1;
                 attr->enable_on_exec = 1;
         }
 
-        return perf_evsel__open_per_thread(evsel, evsel_list->threads, group);
+        return perf_evsel__open_per_thread(evsel, evsel_list->threads,
+                                           group, group_fd);
 }
 
 /*
@@ -396,7 +402,7 @@ static int read_counter(struct perf_evsel *counter)
 static int run_perf_stat(int argc __used, const char **argv)
 {
         unsigned long long t0, t1;
-        struct perf_evsel *counter;
+        struct perf_evsel *counter, *first;
         int status = 0;
         int child_ready_pipe[2], go_pipe[2];
         const bool forks = (argc > 0);
@@ -453,8 +459,10 @@ static int run_perf_stat(int argc __used, const char **argv)
                 close(child_ready_pipe[0]);
         }
 
+        first = list_entry(evsel_list->entries.next, struct perf_evsel, node);
+
         list_for_each_entry(counter, &evsel_list->entries, node) {
-                if (create_perf_stat_counter(counter) < 0) {
+                if (create_perf_stat_counter(counter, first) < 0) {
                         if (errno == EINVAL || errno == ENOSYS || errno == ENOENT) {
                                 if (verbose)
                                         ui__warning("%s event is not supported by the kernel.\n",