debug maskdino (#250)

Avoid fp16 overflow.

Author: HaoZhang534

projects/maskdino/modeling/matcher.py

@@ -125,8 +125,8 @@ def memory_efficient_forward(self, outputs, targets, cost=["cls", "box", "mask"]
             # focal loss
             alpha = 0.25
             gamma = 2.0
-            neg_cost_class = (1 - alpha) * (out_prob ** gamma) * (-(1 - out_prob + 1e-8).log())
-            pos_cost_class = alpha * ((1 - out_prob) ** gamma) * (-(out_prob + 1e-8).log())
+            neg_cost_class = (1 - alpha) * (out_prob ** gamma) * (-(1 - out_prob + 1e-5).log())
+            pos_cost_class = alpha * ((1 - out_prob) ** gamma) * (-(out_prob + 1e-5).log())
             cost_class = pos_cost_class[:, tgt_ids] - neg_cost_class[:, tgt_ids]
 
             # Compute the classification cost. Contrary to the loss, we don't use the NLL,