lockmgr_slock_try
if (lockmgr_slock_try(lk, &x, flags, true)) {
if (__predict_true(lockmgr_slock_try(lk, &x, flags, true))) {
static __always_inline bool lockmgr_slock_try(struct lock *lk, uintptr_t *xp,
if (lockmgr_slock_try(lk, &x, flags, false))