feat(server): add paged attention to flash models (#516)

Closes #478

server/text_generation_server/models/flash_llama.py

@@ -64,10 +64,12 @@ class FlashLlama(FlashCausalLM):
         model = FlashLlamaForCausalLM(config, weights)
 
         torch.distributed.barrier(group=self.process_group)
-        super(FlashCausalLM, self).__init__(
+        super(FlashLlama, self).__init__(
             model=model,
             tokenizer=tokenizer,
-            requires_padding=False,
+            num_layers=len(model.model.layers),
+            num_kv_heads=model.model.num_heads,
+            head_size=model.model.head_size,
             dtype=dtype,
             device=device,
             rank=rank,

server/text_generation_server/models/flash_neox.py

@@ -55,10 +55,12 @@ class FlashNeoXSharded(FlashCausalLM):
         model = FlashGPTNeoXForCausalLM(config, weights)
 
         torch.distributed.barrier(group=self.process_group)
-        super(FlashCausalLM, self).__init__(
+        super(FlashNeoXSharded, self).__init__(
             model=model.to(device),
             tokenizer=tokenizer,
-            requires_padding=False,
+            num_layers=len(model.gpt_neox.layers),
+            num_kv_heads=model.gpt_neox.num_heads,
+            head_size=model.gpt_neox.head_size,
             dtype=dtype,
             device=device,
             rank=rank,

server/text_generation_server/models/flash_rw.py

@@ -55,10 +55,12 @@ class FlashRWSharded(FlashCausalLM):
         model = FlashRWForCausalLM(config, weights)
 
         torch.distributed.barrier(group=self.process_group)
-        super(FlashCausalLM, self).__init__(
+        super(FlashRWSharded, self).__init__(
             model=model.to(device),
             tokenizer=tokenizer,
-            requires_padding=False,
+            num_layers=len(model.transformer.h),
+            num_kv_heads=model.transformer.cache_size,
+            head_size=model.transformer.head_size,
             dtype=dtype,
             device=device,
             rank=rank,

server/text_generation_server/models/flash_santacoder.py

@@ -52,17 +52,22 @@ class FlashSantacoderSharded(FlashCausalLM):
         torch.distributed.barrier(group=self.process_group)
         filenames = weight_files(model_id, revision=revision, extension=".safetensors")
         weights = Weights(
-            filenames, device=device, dtype=dtype, process_group=self.process_group,
-            aliases = {"transformer.wte.weight": ["lm_head.weight"]}
+            filenames,
+            device=device,
+            dtype=dtype,
+            process_group=self.process_group,
+            aliases={"transformer.wte.weight": ["lm_head.weight"]},
         )
 
         model = FlashSantacoderForCausalLM(config, weights)
 
         torch.distributed.barrier(group=self.process_group)
-        super(FlashCausalLM, self).__init__(
+        super(FlashSantacoderSharded, self).__init__(
             model=model.to(device),
             tokenizer=tokenizer,
-            requires_padding=False,
+            num_layers=len(model.transformer.h),
+            num_kv_heads=1,
+            head_size=model.transformer.head_size,
             dtype=dtype,
             device=device,
             rank=rank,

server/text_generation_server/models/model.py

@@ -22,6 +22,9 @@ class Model(ABC):
         rank: int = 0,
         world_size: int = 1,
     ):
+        if torch.cuda.is_available():
+            torch.cuda.set_per_process_memory_fraction(1.0)
+
         self.model = model.eval()
         self.tokenizer = tokenizer
         self.all_special_ids = set(tokenizer.all_special_ids)
@@ -55,6 +58,9 @@ class Model(ABC):
     def generate_token(self, batch: B) -> Tuple[List[GeneratedText], Optional[B]]:
         raise NotImplementedError
 
+    def warmup(self, batch: B, max_total_tokens: int):
+        self.generate_token(batch)
+
     def decode_token(
         self,
         all_input_ids: List[int],

server/text_generation_server/models/seq2seq_lm.py

@@ -127,7 +127,7 @@ class Seq2SeqLMBatch(Batch):
             read_offsets.append(1)
         all_decoder_input_ids = decoder_input_ids.view(-1).split(1)
 
-        max_tokens = len(inputs) * max_input_length + max_decode_tokens
+        max_tokens = len(inputs) * (max_input_length + max_decode_tokens)
 
         return cls(
             batch_id=pb.id,

server/text_generation_server/server.py

@@ -53,6 +53,13 @@ class TextGenerationService(generate_pb2_grpc.TextGenerationServiceServicer):
 
         return generate_pb2.FilterBatchResponse(batch=filtered_batch.to_pb())
 
+    async def Warmup(self, request, context):
+        batch = self.model.batch_type.from_pb(
+            request.batch, self.model.tokenizer, self.model.dtype, self.model.device
+        )
+        self.model.warmup(batch, request.max_total_tokens)
+        return generate_pb2.WarmupResponse()
+
     async def Prefill(self, request, context):
         batch = self.model.batch_type.from_pb(
             request.batch, self.model.tokenizer, self.model.dtype, self.model.device

server/text_generation_server/utils/tokens.py

@@ -216,6 +216,8 @@ class HeterogeneousNextTokenChooser:
 
         self.seeds = seeds
         self.do_sample = do_sample
+        self.dtype = dtype
+        self.device = device
 
     def __call__(self, input_ids: torch.Tensor, scores: torch.Tensor):
         if self.watermark_processor is not None:

server/text_generation_server/utils/weights.py

@@ -5,7 +5,14 @@ import torch
 
 
 class Weights:
-    def __init__(self, filenames: List[Path], device, dtype, process_group, aliases: Optional[Dict[str, List[str]]]=None):
+    def __init__(
+        self,
+        filenames: List[Path],
+        device,
+        dtype,
+        process_group,
+        aliases: Optional[Dict[str, List[str]]] = None,
+    ):
         routing = {}
         for filename in filenames:
             with safe_open(filename, framework="pytorch") as f:
@@ -43,7 +50,7 @@ class Weights:
         return str(filename), tensor_name
 
     def _get_slice(self, tensor_name: str):
-        filename, tensor_name= self.get_filename(tensor_name)
+        filename, tensor_name = self.get_filename(tensor_name)
         f = self._get_handle(filename)
         slice_ = f.get_slice(tensor_name)
         return slice_
@@ -94,12 +101,20 @@ class Weights:
     def get_multi_weights_col(self, prefixes: List[str], quantize: str, dim: int):
         if quantize == "gptq":
             try:
-                qweight = torch.cat([self.get_sharded(f"{p}.qweight", dim=1) for p in prefixes], dim=1)
+                qweight = torch.cat(
+                    [self.get_sharded(f"{p}.qweight", dim=1) for p in prefixes], dim=1
+                )
             except RuntimeError:
-                raise RuntimeError("Cannot load `gptq` weight, make sure the model is already quantized, or quantize it with `text-generation-server quantize ORIGINAL_MODEL_ID NEW_MODEL_ID`")
-
-            qzeros = torch.cat([self.get_sharded(f"{p}.qzeros", dim=1) for p in prefixes], dim=1)
-            scales = torch.cat([self.get_sharded(f"{p}.scales", dim=1) for p in prefixes], dim=1)
+                raise RuntimeError(
+                    "Cannot load `gptq` weight, make sure the model is already quantized, or quantize it with `text-generation-server quantize ORIGINAL_MODEL_ID NEW_MODEL_ID`"
+                )
+
+            qzeros = torch.cat(
+                [self.get_sharded(f"{p}.qzeros", dim=1) for p in prefixes], dim=1
+            )
+            scales = torch.cat(
+                [self.get_sharded(f"{p}.scales", dim=1) for p in prefixes], dim=1
+            )
             w = [self.get_tensor(f"{p}.g_idx") for p in prefixes]
             for w2 in w[1:]:
                 torch.testing.assert_close(w2, w[0])
@@ -118,7 +133,9 @@ class Weights:
             try:
                 qweight = self.get_sharded(f"{prefix}.qweight", dim=0)
             except RuntimeError:
-                raise RuntimeError("Cannot load `gptq` weight, make sure the model is already quantized, or quantize it with `text-generation-server quantize ORIGINAL_MODEL_ID NEW_MODEL_ID`")
+                raise RuntimeError(
+                    "Cannot load `gptq` weight, make sure the model is already quantized, or quantize it with `text-generation-server quantize ORIGINAL_MODEL_ID NEW_MODEL_ID`"
+                )
             qzeros = self.get_tensor(f"{prefix}.qzeros")
             scales = self.get_tensor(f"{prefix}.scales")
             g_idx = self.get_sharded(f"{prefix}.g_idx", dim=0)