Gaudi: Use exponential growth to replace BATCH_BUCKET_SIZE (#3131)

* Gaudi: Use exponential growth to replace BATCH_BUCKET_SIZE

Signed-off-by: yuanwu <yuan.wu@intel.com>

* Remove debug modifications

Signed-off-by: yuanwu <yuan.wu@intel.com>

---------

Signed-off-by: yuanwu <yuan.wu@intel.com>

Author: yuanwu2017

backends/gaudi/server/text_generation_server/models/causal_lm.py

@@ -57,8 +57,7 @@
 PAD_SEQUENCE_TO_MULTIPLE_OF = int(os.environ.get("PAD_SEQUENCE_TO_MULTIPLE_OF", 256))
 CHUNK_SIZES = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048]
 LAZY_MODE = int(os.environ.get("PT_HPU_LAZY_MODE", 1))
-BATCH_BUCKET_SIZE = int(os.environ.get("BATCH_BUCKET_SIZE", 8))
-PREFILL_BATCH_BUCKET_SIZE = int(os.environ.get("PREFILL_BATCH_BUCKET_SIZE", 2))
+BATCH_SIZE_EXPONENT_BASE = int(os.environ.get("BATCH_SIZE_EXPONENT_BASE", 2))
 MAX_BATCH_SIZE = (
     int(os.environ.get("MAX_BATCH_SIZE"))
     if os.environ.get("MAX_BATCH_SIZE") is not None
@@ -74,10 +73,16 @@ def torch_compile_for_eager(func):
     )
 
 
-def round_up(number, k):
+def round_up_seq(number, k):
     return (number + k - 1) // k * k
 
 
+def round_up_batch(number):
+    return BATCH_SIZE_EXPONENT_BASE ** (
+        math.ceil(math.log(number, BATCH_SIZE_EXPONENT_BASE))
+    )
+
+
 def to_tensor_indices(indices, device):
     return torch.tensor(indices, dtype=torch.long, device=device)
 
@@ -399,7 +404,7 @@ def recombine(
 
         total_requests = sum(len(b) for b in batches)
         new_bs = total_requests
-        new_bs = round_up(total_requests, BATCH_BUCKET_SIZE)
+        new_bs = round_up_batch(total_requests)
 
         batch_id = batches[0].batch_id
         device = batches[0].input_ids.device
@@ -540,7 +545,7 @@ def from_pb(
         # TODO: by tokenizing all inputs at once we loose information on actual input lengths
         # this means that we cannot shift inputs to the left after a long input sequence
         # was filtered out
-        new_bs = round_up(len(requests), PREFILL_BATCH_BUCKET_SIZE)
+        new_bs = round_up_batch(len(requests))
         missing_inputs = new_bs - len(inputs)
         dummy_inputs = ["?"] * missing_inputs
         parameters = [r.parameters for r in pb.requests]
@@ -572,7 +577,7 @@ def from_pb(
             assert (
                 PAD_SEQUENCE_TO_MULTIPLE_OF <= max_input_length
             ), "PAD_SEQUENCE_TO_MULTIPLE_OF cannot be higher than max_input_length"
-            rounded_seq_len = round_up(input_len + 1, PAD_SEQUENCE_TO_MULTIPLE_OF)
+            rounded_seq_len = round_up_seq(input_len + 1, PAD_SEQUENCE_TO_MULTIPLE_OF)
             if rounded_seq_len <= max_input_length:
                 bucket_size = rounded_seq_len - 1
             else:
@@ -1068,10 +1073,10 @@ def generate_token(
         if (
             self.enable_hpu_graph
             and self.limit_hpu_graph
-            and round_up(batch.batch_size, BATCH_BUCKET_SIZE) != self.prev_bs
+            and round_up_batch(batch.batch_size) != self.prev_bs
         ):
             self.model.clear_cache()
-            self.prev_bs = round_up(batch.batch_size, BATCH_BUCKET_SIZE)
+            self.prev_bs = round_up_batch(batch.batch_size)
         dbg_trace(
             scenario,
             f"bs:{batch.batch_size} num_reqs:{len(batch.requests)} seq_len:{batch.seq_length} padding:{batch.right_padding}",
@@ -1325,15 +1330,14 @@ def warmup(
 
         # Warmup prefill batch_size
         max_input_tokens = request.max_input_tokens
+        max_exp = math.ceil(math.log(max_prefill_batch_size, BATCH_SIZE_EXPONENT_BASE))
         prefill_batch_size_list = [
-            batch
-            for batch in range(
-                PREFILL_BATCH_BUCKET_SIZE,
-                max_prefill_batch_size,
-                PREFILL_BATCH_BUCKET_SIZE,
+            BATCH_SIZE_EXPONENT_BASE**exp
+            for exp in range(
+                0,
+                max_exp + 1,
             )
         ]
-        prefill_batch_size_list.append(max_prefill_batch_size)
         prefill_seqlen_list = [
             seq
             for seq in range(
@@ -1370,12 +1374,10 @@ def warmup(
         )
 
         max_decode_batch_size = math.floor(MAX_BATCH_TOTAL_TOKENS / MAX_TOTAL_TOKENS)
-        max_decode_batch_size = round_up(max_decode_batch_size, BATCH_BUCKET_SIZE)
+        max_exp = math.ceil(math.log(max_decode_batch_size, BATCH_SIZE_EXPONENT_BASE))
         decode_batch_size_list = [
-            i
-            for i in range(BATCH_BUCKET_SIZE, max_decode_batch_size, BATCH_BUCKET_SIZE)
+            BATCH_SIZE_EXPONENT_BASE**exp for exp in range(0, max_exp + 1)
         ]
-        decode_batch_size_list.append(max_decode_batch_size)
         decode_batch_size_list.sort(reverse=True)
 
         try: