Free mem trigger with all2all for sync trigger eviction

fbgemm_gpu/fbgemm_gpu/split_table_batched_embeddings_ops_common.py

@@ -240,6 +240,19 @@ def validate(self) -> None:
         ), "backend_return_whole_row can only be enabled when enable_optimizer_offloading is enabled"
 
 
+class KVZCHEvictionTBEConfig(NamedTuple):
+    # Eviction trigger model for kvzch table: 0: disabled, 1: iteration, 2: mem_util, 3: manual, 4: id count, 5: free_mem
+    kvzch_eviction_trigger_mode: int = 2  # mem_util
+    # Minimum free memory (in GB) required before triggering eviction when using free_mem trigger mode.
+    eviction_free_mem_threshold_gb: int = 200  # 200GB
+    # Number of batches between checks for free memory threshold when using free_mem trigger mode.
+    eviction_free_mem_check_interval_batch: int = 1000
+    # The width of each feature score bucket used for threshold calculation in feature score-based eviction.
+    threshold_calculation_bucket_stride: float = 0.2
+    # Total number of feature score buckets used for threshold calculation in feature score-based eviction.
+    threshold_calculation_bucket_num: Optional[int] = 1000000  # 1M
+
+
 class BackendType(enum.IntEnum):
     SSD = 0
     DRAM = 1