WF_SYNC
if (wake_flags & WF_SYNC)
WARN_ON_ONCE(wake_flags & ~(WF_SYNC|WF_CURRENT_CPU));
SCX_WAKE_SYNC = WF_SYNC,
int sync = (wake_flags & WF_SYNC) && !(current->flags & PF_EXITING);
if (wake_flags & WF_SYNC)
__wake_up_common_lock(wq_head, mode, 1, WF_SYNC, key);
__wake_up_common(wq_head, mode, 1, WF_SYNC, key);