perf_counter: Log vfork as a fork event

Right now we don't output vfork events. Even though we should
always see an exec after a vfork, we may get perfcounter
samples between the vfork and exec. These samples can lead to
some confusion when parsing perfcounter data.

To keep things consistent we should always log a fork event. It
will result in a little more log data, but is less confusing to
trace parsing tools.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090716104817.589309391@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 6 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 467746b3f0aa..4812d60b29f8 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1408,14 +1408,11 @@ long do_fork(unsigned long clone_flags,
                 if (clone_flags & CLONE_VFORK) {
                         p->vfork_done = &vfork;
                         init_completion(&vfork);
-                } else if (!(clone_flags & CLONE_VM)) {
-                        /*
-                         * vfork will do an exec which will call
-                         * set_task_comm()
-                         */
-                        perf_counter_fork(p);
                 }
 
+                if (!(clone_flags & CLONE_THREAD))
+                        perf_counter_fork(p);
+
                 audit_finish_fork(p);
                 tracehook_report_clone(regs, clone_flags, nr, p);