aux: Suspend signal helper for shell commands

The clone() system call with a larger executable (like /bin/sh) may have
difficulty to make progress on some platforms if interrupted frequently.
So suspend the signal helper process for the duration of the syscall.
This is needed to solve an actual problem by the next patch.

v2:
- Clarify/fix code comments. (Chris)
- Update igt_system_quiet() as well accordingly.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index 499a1679..688ad1b8 100644
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -55,6 +55,8 @@ extern int num_trash_bos;
 /* generally useful helpers */
 void igt_fork_signal_helper(void);
 void igt_stop_signal_helper(void);
+void igt_suspend_signal_helper(void);
+void igt_resume_signal_helper(void);
 
 void igt_fork_shrink_helper(int fd);
 void igt_stop_shrink_helper(void);