perf evsel: Support event groups

The perf_evsel__open now have an extra boolean argument specifying if
event grouping is desired.

The first file descriptor created on a CPU becomes the group leader.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index da90902..b5fe522 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -169,7 +169,7 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
                                    PERF_FORMAT_TOTAL_TIME_RUNNING;
 
        if (system_wide)
-               return perf_evsel__open_per_cpu(evsel, cpus);
+               return perf_evsel__open_per_cpu(evsel, cpus, false);
 
        attr->inherit = !no_inherit;
        if (target_pid == -1 && target_tid == -1) {
@@ -177,7 +177,7 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
                attr->enable_on_exec = 1;
        }
 
-       return perf_evsel__open_per_thread(evsel, threads);
+       return perf_evsel__open_per_thread(evsel, threads, false);
 }
 
 /*

diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 5dcdba6..4282d67 100644 (file)
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -289,7 +289,7 @@ static int test__open_syscall_event(void)
                goto out_thread_map_delete;
        }
 
-       if (perf_evsel__open_per_thread(evsel, threads) < 0) {
+       if (perf_evsel__open_per_thread(evsel, threads, false) < 0) {
                pr_debug("failed to open counter: %s, "
                         "tweak /proc/sys/kernel/perf_event_paranoid?\n",
                         strerror(errno));
@@ -364,7 +364,7 @@ static int test__open_syscall_event_on_all_cpus(void)
                goto out_thread_map_delete;
        }
 
-       if (perf_evsel__open(evsel, cpus, threads) < 0) {
+       if (perf_evsel__open(evsel, cpus, threads, false) < 0) {
                pr_debug("failed to open counter: %s, "
                         "tweak /proc/sys/kernel/perf_event_paranoid?\n",
                         strerror(errno));

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f5cfed6..da473ec 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -128,7 +128,7 @@ 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)
+                             struct thread_map *threads, bool group)
 {
        int cpu, thread;
 
@@ -137,12 +137,18 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
                return -1;
 
        for (cpu = 0; cpu < cpus->nr; cpu++) {
+               int group_fd = -1;
+
                for (thread = 0; thread < threads->nr; thread++) {
                        FD(evsel, cpu, thread) = sys_perf_event_open(&evsel->attr,
                                                                     threads->map[thread],
-                                                                    cpus->map[cpu], -1, 0);
+                                                                    cpus->map[cpu],
+                                                                    group_fd, 0);
                        if (FD(evsel, cpu, thread) < 0)
                                goto out_close;
+
+                       if (group && group_fd == -1)
+                               group_fd = FD(evsel, cpu, thread);
                }
        }
 
@@ -175,10 +181,9 @@ static struct {
        .threads = { -1, },
 };
 
-int perf_evsel__open(struct perf_evsel *evsel,
-                    struct cpu_map *cpus, struct thread_map *threads)
+int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
+                    struct thread_map *threads, bool group)
 {
-
        if (cpus == NULL) {
                /* Work around old compiler warnings about strict aliasing */
                cpus = &empty_cpu_map.map;
@@ -187,15 +192,17 @@ int perf_evsel__open(struct perf_evsel *evsel,
        if (threads == NULL)
                threads = &empty_thread_map.map;
 
-       return __perf_evsel__open(evsel, cpus, threads);
+       return __perf_evsel__open(evsel, cpus, threads, group);
 }
 
-int perf_evsel__open_per_cpu(struct perf_evsel *evsel, struct cpu_map *cpus)
+int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
+                            struct cpu_map *cpus, bool group)
 {
-       return __perf_evsel__open(evsel, cpus, &empty_thread_map.map);
+       return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group);
 }
 
-int perf_evsel__open_per_thread(struct perf_evsel *evsel, struct thread_map *threads)
+int perf_evsel__open_per_thread(struct perf_evsel *evsel,
+                               struct thread_map *threads, bool group)
 {
-       return __perf_evsel__open(evsel, &empty_cpu_map.map, threads);
+       return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group);
 }

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index b2d755f..0962b50 100644 (file)
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -45,10 +45,12 @@ int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus);
 void perf_evsel__free_fd(struct perf_evsel *evsel);
 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
 
-int perf_evsel__open_per_cpu(struct perf_evsel *evsel, struct cpu_map *cpus);
-int perf_evsel__open_per_thread(struct perf_evsel *evsel, struct thread_map *threads);
-int perf_evsel__open(struct perf_evsel *evsel, 
-                    struct cpu_map *cpus, struct thread_map *threads);
+int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
+                            struct cpu_map *cpus, bool group);
+int perf_evsel__open_per_thread(struct perf_evsel *evsel,
+                               struct thread_map *threads, bool group);
+int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
+                    struct thread_map *threads, bool group);
 
 #define perf_evsel__match(evsel, t, c)         \
        (evsel->attr.type == PERF_TYPE_##t &&   \