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, 31 insertions, 12 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index b46f6e4bff3c..e42626422587 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -16,6 +16,7 @@
 #include "thread_map.h"
 
 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
+#define GROUP_FD(group_fd, cpu) (*(int *)xyarray__entry(group_fd, cpu, 0))
 
 int __perf_evsel__sample_size(u64 sample_type)
 {
@@ -204,15 +205,16 @@ int __perf_evsel__read(struct perf_evsel *evsel,
 }
 
 static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
-                              struct thread_map *threads, bool group)
+                              struct thread_map *threads, bool group,
+                              struct xyarray *group_fds)
 {
         int cpu, thread;
         unsigned long flags = 0;
-        int pid = -1;
+        int pid = -1, err;
 
         if (evsel->fd == NULL &&
             perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
-                return -1;
+                return -ENOMEM;
 
         if (evsel->cgrp) {
                 flags = PERF_FLAG_PID_CGROUP;
@@ -220,7 +222,7 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
         }
 
         for (cpu = 0; cpu < cpus->nr; cpu++) {
-                int group_fd = -1;
+                int group_fd = group_fds ? GROUP_FD(group_fds, cpu) : -1;
 
                 for (thread = 0; thread < threads->nr; thread++) {
 
@@ -231,8 +233,10 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
                                                                      pid,
                                                                      cpus->map[cpu],
                                                                      group_fd, flags);
-                        if (FD(evsel, cpu, thread) < 0)
+                        if (FD(evsel, cpu, thread) < 0) {
+                                err = -errno;
                                 goto out_close;
+                        }
 
                         if (group && group_fd == -1)
                                 group_fd = FD(evsel, cpu, thread);
@@ -249,7 +253,17 @@ out_close:
                 }
                 thread = threads->nr;
         } while (--cpu >= 0);
-        return -1;
+        return err;
+}
+
+void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
+{
+        if (evsel->fd == NULL)
+                return;
+
+        perf_evsel__close_fd(evsel, ncpus, nthreads);
+        perf_evsel__free_fd(evsel);
+        evsel->fd = NULL;
 }
 
 static struct {
@@ -269,7 +283,8 @@ static struct {
 };
 
 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
-                     struct thread_map *threads, bool group)
+                     struct thread_map *threads, bool group,
+                     struct xyarray *group_fd)
 {
         if (cpus == NULL) {
                 /* Work around old compiler warnings about strict aliasing */
@@ -279,19 +294,23 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
         if (threads == NULL)
                 threads = &empty_thread_map.map;
 
-        return __perf_evsel__open(evsel, cpus, threads, group);
+        return __perf_evsel__open(evsel, cpus, threads, group, group_fd);
 }
 
 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
-                             struct cpu_map *cpus, bool group)
+                             struct cpu_map *cpus, bool group,
+                             struct xyarray *group_fd)
 {
-        return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group);
+        return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group,
+                                  group_fd);
 }
 
 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
-                                struct thread_map *threads, bool group)
+                                struct thread_map *threads, bool group,
+                                struct xyarray *group_fd)
 {
-        return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group);
+        return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group,
+                                  group_fd);
 }
 
 static int perf_event__parse_id_sample(const union perf_event *event, u64 type,