3 files changed, 23 insertions, 30 deletions

diff --git a/lib/igt_core.c b/lib/igt_core.c
index 0a2ddad9..1287ff65 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -843,56 +843,45 @@ bool __igt_fork_helper(struct igt_helper_process *proc)
 }
 
 /**
- * igt_stop_helper:
+ * igt_wait_helper:
  * @proc: #igt_helper_process structure
  *
- * Terminates a helper process. It is an error to call this on a helper process
- * which hasn't been spawned yet.
+ * Joins a helper process. It is an error to call this on a helper process which
+ * hasn't been spawned yet.
  */
-void igt_stop_helper(struct igt_helper_process *proc)
+int igt_wait_helper(struct igt_helper_process *proc)
 {
-	int status, ret;
+	int status = -1;
 
 	assert(proc->running);
 
-	ret = kill(proc->pid,
-		   proc->use_SIGKILL ? SIGKILL : SIGTERM);
-	assert(ret == 0);
-
-	while (waitpid(proc->pid, &status, 0) == -1 &&
-	       errno == EINTR)
-		;
-	igt_assert(WIFSIGNALED(status) &&
-		   WTERMSIG(status) == (proc->use_SIGKILL ? SIGKILL : SIGTERM));
+	waitpid(proc->pid, &status, WNOHANG);
 
 	proc->running = false;
 
 	helper_process_pids[proc->id] = -1;
 	helper_process_count--;
+
+	return status;
 }
 
 /**
- * igt_wait_helper:
+ * igt_stop_helper:
  * @proc: #igt_helper_process structure
  *
- * Joins a helper process. It is an error to call this on a helper process which
- * hasn't been spawned yet.
+ * Terminates a helper process. It is an error to call this on a helper process
+ * which hasn't been spawned yet.
  */
-void igt_wait_helper(struct igt_helper_process *proc)
+void igt_stop_helper(struct igt_helper_process *proc)
 {
 	int status;
 
-	assert(proc->running);
-
-	while (waitpid(proc->pid, &status, 0) == -1 &&
-	       errno == EINTR)
-		;
-	igt_assert(WIFEXITED(status) && WEXITSTATUS(status) == 0);
-
-	proc->running = false;
+	/* failure here means the pid is already dead and so waiting is safe */
+	kill(proc->pid, proc->use_SIGKILL ? SIGKILL : SIGTERM);
 
-	helper_process_pids[proc->id] = -1;
-	helper_process_count--;
+	status = igt_wait_helper(proc);
+	assert(WIFSIGNALED(status) &&
+	       WTERMSIG(status) == (proc->use_SIGKILL ? SIGKILL : SIGTERM));
 }
 
 static void children_exit_handler(int sig)
diff --git a/lib/igt_core.h b/lib/igt_core.h
index 0e84e980..2838cb18 100644
--- a/lib/igt_core.h
+++ b/lib/igt_core.h
@@ -420,7 +420,7 @@ bool __igt_fork_helper(struct igt_helper_process *proc);
  */
 #define igt_fork_helper(proc) \
 	for (; __igt_fork_helper(proc); exit(0))
-void igt_wait_helper(struct igt_helper_process *proc);
+int igt_wait_helper(struct igt_helper_process *proc);
 void igt_stop_helper(struct igt_helper_process *proc);
 
 /* exit handler code */
diff --git a/tests/pm_rps.c b/tests/pm_rps.c
index 96fec991..8593e364 100644
--- a/tests/pm_rps.c
+++ b/tests/pm_rps.c
@@ -253,8 +253,12 @@ static void load_helper_run(enum load load)
 
 static void load_helper_stop(void)
 {
+	int status;
+
 	kill(lh.igt_proc.pid, SIGUSR1);
-	igt_wait_helper(&lh.igt_proc);
+	status = igt_wait_helper(&lh.igt_proc);
+
+	igt_assert(WIFSIGNALED(status) && WTERMSIG(status) == SIGUSR1);
 }
 
 static void load_helper_init(void)