Resolve MPS's lack of cummax

Author: sadra-barikbin

ignite/metrics/vision/object_detection_average_precision_recall.py

@@ -1,3 +1,4 @@
+import os
 from typing import Callable, cast, Dict, List, Optional, Sequence, Tuple, Union
 
 import torch
@@ -234,7 +235,10 @@ def _compute_average_precision(self, recall: torch.Tensor, precision: torch.Tens
         Returns:
             average_precision: (n-1)-dimensional tensor containing the average precision for mean dimensions.
         """
+        mps_cpu_fallback = os.environ.get("PYTORCH_ENABLE_MPS_FALLBACK", False)
+        os.environ["PYTORCH_ENABLE_MPS_FALLBACK"] = True
         precision_integrand = precision.flip(-1).cummax(dim=-1).values.flip(-1)
+        os.environ["PYTORCH_ENABLE_MPS_FALLBACK"] = mps_cpu_fallback
         rec_thresholds = cast(torch.Tensor, self.rec_thresholds).repeat((*recall.shape[:-1], 1))
         rec_thresh_indices = (
             torch.searchsorted(recall, rec_thresholds)