fix UOp.metadata on KERNEL op [pr] (tinygrad#8953)

* fix UOp.metadata on KERNEL op [pr]

* hotfix: is not None

Author: Qazalin

tinygrad/engine/schedule.py

@@ -267,8 +267,8 @@ def inputs(self) -> tuple[Buffer, ...]:
   def output_idxs(self) -> tuple[int, ...]: return tuple(x.src[0].arg for x in self.ast.src) if self.ast.op is Ops.SINK else (0,)
 
 def kernel_to_si(k:UOp) -> ScheduleItem:
-  assert k.op is Ops.KERNEL, f"must be KERNEL {k}"
-  return ScheduleItem(k.arg.ast, tuple(u.buf_uop.buffer for u in k.src), k.arg.metadata)
+  assert k.op is Ops.KERNEL and isinstance(k.metadata, tuple), f"must be KERNEL {k}"
+  return ScheduleItem(k.arg.ast, tuple(u.buf_uop.buffer for u in k.src), k.metadata)
 
 # **** Kernel creation
 
@@ -433,7 +433,7 @@ def create_schedule_with_vars(big_sink:UOp) -> tuple[list[ScheduleItem], dict[Va
   for k,v in tensor_map.items():
     if (b:=buffer_map.get(v)) is not None:
       buf_tensors.setdefault(b, []).append(k)
-      ops_metadata[b] = k.metadata
+      if isinstance(k.metadata, Metadata): ops_metadata[b] = k.metadata
   realize_map = group_realizes(sink, ctx:=ScheduleContext(ops_metadata))
   if len(realize_map) == 0: return [], {}, becomes_map
 
@@ -460,7 +460,7 @@ def create_schedule_with_vars(big_sink:UOp) -> tuple[list[ScheduleItem], dict[Va
   in_degree: defaultdict[ScheduleItem, int] = defaultdict(int)
   for si in prescheduled:
     # realize outputs before a parent is assigned to
-    parents_assigns = dedup(xsi for x in ctx.preloads[si.bufs[0]] if (xsi:=schedule_targets.get(x.buffer)) and xsi is not si)
+    parents_assigns = dedup(xsi for x in ctx.preloads[si.bufs[0]] if (xsi:=schedule_targets.get(x.buffer)) is not None and xsi is not si)
     for assign in parents_assigns:
       graph[si].append(assign)
       in_degree[assign] += 1

tinygrad/ops.py

@@ -506,7 +506,7 @@ def copy_to_device(self, device:str|tuple[str, ...], clone:bool=False) -> UOp:
     return ret
   def clone(self) -> UOp: return self.copy_to_device(self.device, clone=True)
   @property
-  def metadata(self): return all_metadata.get(self, None)
+  def metadata(self) -> tuple[Metadata, ...]|Metadata|None: return self.arg.metadata if self.op is Ops.KERNEL else all_metadata.get(self, None)
 
   # *** uop movement ops ***