Fix some OOM issues with split attention.

comfy/ldm/modules/attention.py

@@ -229,7 +229,7 @@ def attention_split(q, k, v, heads, mask=None):
 
     gb = 1024 ** 3
     tensor_size = q.shape[0] * q.shape[1] * k.shape[1] * element_size
-    modifier = 3 if element_size == 2 else 2.5
+    modifier = 3
     mem_required = tensor_size * modifier
     steps = 1
 
@@ -257,10 +257,10 @@ def attention_split(q, k, v, heads, mask=None):
                         s1 = einsum('b i d, b j d -> b i j', q[:, i:end].float(), k.float()) * scale
                 else:
                     s1 = einsum('b i d, b j d -> b i j', q[:, i:end], k) * scale
-                first_op_done = True
 
                 s2 = s1.softmax(dim=-1).to(v.dtype)
                 del s1
+                first_op_done = True
 
                 r1[:, i:end] = einsum('b i j, b j d -> b i d', s2, v)
                 del s2