maybePerformBlockedException (cap, tso);
if (tso->what_next == ThreadKilled) { return; }
+ // NB. Blackholing is *not* optional, we must either do lazy
+ // blackholing, or eager blackholing consistently. See Note
+ // [upd-black-hole] in sm/Scav.c.
+
stack_end = &tso->stack[tso->stack_size];
frame = (StgClosure *)tso->sp;