diff --git a/nanovllm/__init__.py b/nanovllm/__init__.py
index e84e8cc..551af23 100644
--- a/nanovllm/__init__.py
+++ b/nanovllm/__init__.py
@@ -1,2 +1,2 @@
 from nanovllm.llm import LLM
-from nanovllm.sampling_params import SamplingParams
\ No newline at end of file
+from nanovllm.sampling_params import SamplingParams
diff --git a/nanovllm/config.py b/nanovllm/config.py
index ce9446b..6c4e7f9 100644
--- a/nanovllm/config.py
+++ b/nanovllm/config.py
@@ -1,14 +1,16 @@
+import os
 from dataclasses import dataclass
 from transformers import AutoConfig
 
 
 @dataclass
 class Config:
-    model: str = ''
+    model: str
     max_num_batched_tokens: int = 32768
     max_num_seqs: int = 512
     max_model_len: int = 4096
     gpu_memory_utilization: float = 0.9
+    tensor_parallel_size: int = 1
     enforce_eager: bool = False
     hf_config: AutoConfig | None = None
     eos: int = -1
@@ -16,5 +18,8 @@ class Config:
     num_kvcache_blocks: int = -1
 
     def __post_init__(self):
-        assert self.model
-        assert self.kvcache_block_size % 256 == 0
\ No newline at end of file
+        assert os.path.isdir(self.model)
+        assert self.kvcache_block_size % 256 == 0
+        assert 1 <= self.tensor_parallel_size <= 8
+        self.hf_config = AutoConfig.from_pretrained(self.model)
+        self.max_model_len = min(self.max_model_len, self.hf_config.max_position_embeddings)
diff --git a/nanovllm/engine/block_manager.py b/nanovllm/engine/block_manager.py
index f916fc4..9327e95 100644
--- a/nanovllm/engine/block_manager.py
+++ b/nanovllm/engine/block_manager.py
@@ -107,7 +107,7 @@ class BlockManager:
             block_table.append(block_id)
         elif len(seq) % self.block_size == 0:
             assert last_block.hash == -1
-            token_ids = seq.last_block()
+            token_ids = seq.block(seq.num_blocks-1)
             prefix = self.blocks[block_table[-2]].hash if len(block_table) > 1 else -1
             h = compute_hash(token_ids, prefix)
             last_block.update(h, token_ids)
diff --git a/nanovllm/engine/llm_engine.py b/nanovllm/engine/llm_engine.py
index 07a53c2..53a4887 100644
--- a/nanovllm/engine/llm_engine.py
+++ b/nanovllm/engine/llm_engine.py
@@ -1,6 +1,9 @@
+import atexit
+from dataclasses import fields
 from time import perf_counter
 from tqdm.auto import tqdm
 from transformers import AutoConfig, AutoTokenizer
+import torch.multiprocessing as mp
 
 from nanovllm.config import Config
 from nanovllm.sampling_params import SamplingParams
@@ -12,17 +15,27 @@ from nanovllm.engine.model_runner import ModelRunner
 class LLMEngine:
 
     def __init__(self, model, **kwargs):
-        config = Config(model)
-        for k, v in kwargs.items():
-            if hasattr(config, k):
-                setattr(config, k, v)
-        Sequence.block_size = config.kvcache_block_size
-        config.hf_config = AutoConfig.from_pretrained(config.model)
-        config.max_model_len = min(config.max_model_len, config.hf_config.max_position_embeddings)
+        config_fileds = {field.name for field in fields(Config)}
+        config_kwargs = {k: v for k, v in kwargs.items() if k in config_fileds}
+        config = Config(model, **config_kwargs)
+        self.ps = []
+        self.events = []
+        for i in range(1, config.tensor_parallel_size):
+            event = mp.Event()
+            process = mp.Process(target=ModelRunner, args=(config, i, event))
+            process.start()
+            self.ps.append(process)
+            self.events.append(event)
+        self.model_runner = ModelRunner(config, 0, self.events)
         self.tokenizer = AutoTokenizer.from_pretrained(config.model, use_fast=True)
         config.eos = self.tokenizer.eos_token_id
-        self.model_runner = ModelRunner(config)
         self.scheduler = Scheduler(config)
+        atexit.register(self.exit)
+
+    def exit(self):
+        self.model_runner.call("exit")
+        for p in self.ps:
+            p.join()
 
     def add_request(self, prompt: str | list[int], sampling_params: SamplingParams):
         if isinstance(prompt, str):
@@ -32,7 +45,7 @@ class LLMEngine:
 
     def step(self):
         seqs, is_prefill = self.scheduler.schedule()
-        token_ids = self.model_runner.run(seqs, is_prefill)
+        token_ids = self.model_runner.call("run", seqs, is_prefill)
         self.scheduler.postprocess(seqs, token_ids)
         outputs = [(seq.seq_id, seq.completion_token_ids) for seq in seqs if seq.is_finished]
         num_tokens = sum(len(seq) for seq in seqs) if is_prefill else -len(seqs)
@@ -79,4 +92,4 @@ class LLMEngine:
         outputs = [{"text": self.tokenizer.decode(token_ids), "token_ids": token_ids} for token_ids in outputs]
         if use_tqdm:
             pbar.close()
-        return outputs
\ No newline at end of file
+        return outputs
diff --git a/nanovllm/engine/model_runner.py b/nanovllm/engine/model_runner.py
index b39fabb..8973310 100644
--- a/nanovllm/engine/model_runner.py
+++ b/nanovllm/engine/model_runner.py
@@ -1,4 +1,8 @@
+import pickle
 import torch
+import torch.distributed as dist
+from multiprocess.synchronize import Event
+from multiprocess.shared_memory import SharedMemory
 
 from nanovllm.config import Config
 from nanovllm.engine.sequence import Sequence
@@ -11,12 +15,17 @@ from nanovllm.utils.loader import load_model
 
 class ModelRunner:
 
-    def __init__(self, config: Config):
+    def __init__(self, config: Config, rank: int, event: Event | list[Event]):
         self.config = config
         hf_config = config.hf_config
         self.block_size = config.kvcache_block_size
         self.enforce_eager = config.enforce_eager
+        self.world_size = config.tensor_parallel_size
+        self.rank = rank
+        self.event = event
     
+        dist.init_process_group("nccl", "tcp://localhost:2333", world_size=self.world_size, rank=rank)
+        torch.cuda.set_device(rank)
         default_dtype = torch.get_default_dtype()
         torch.set_default_dtype(hf_config.torch_dtype)
         torch.set_default_device("cuda")
@@ -29,14 +38,63 @@ class ModelRunner:
         torch.set_default_device("cpu")
         torch.set_default_dtype(default_dtype)
 
+        if self.world_size > 1:
+            if rank == 0:
+                self.shm = SharedMemory(name="nanovllm", create=True, size=2**20)
+                dist.barrier()
+            else:
+                dist.barrier()
+                self.shm = SharedMemory(name="nanovllm")
+                self.loop()
+
+    def exit(self):
+        if self.world_size > 1:
+            self.shm.close()
+            if self.rank == 0:
+                self.shm.unlink()
+        # dist.destroy_process_group()
+
+    def loop(self):
+        while True:
+            method_name, args = self.read_shm()
+            self.call(method_name, *args)
+            if method_name == "exit":
+                break
+
+    def read_shm(self):
+        assert self.world_size > 1 and self.rank
+        self.event.wait()
+        n = int.from_bytes(self.shm.buf[0:4], "little")
+        method_name, *args = pickle.loads(self.shm.buf[4:n+4])
+        self.event.clear()
+        return method_name, args
+
+    def write_shm(self, method_name, *args):
+        assert self.world_size > 1 and not self.rank
+        data = pickle.dumps([method_name, *args])
+        n = len(data)
+        assert n + 4 <= self.shm.size
+        self.shm.buf[0:4] = n.to_bytes(4, "little")
+        self.shm.buf[4:n+4] = data
+        for event in self.event:
+            event.set()
+
+    def call(self, method_name, *args):
+        if self.world_size > 1 and self.rank == 0:
+            self.write_shm(method_name, *args)
+        method = getattr(self, method_name, None)
+        assert callable(method)
+        return method(*args)
+
     def allocate_kv_cache(self, gpu_memory_utilization):
         config = self.config
         hf_config = config.hf_config
         total, used, _ = get_gpu_memory()
         free = total * gpu_memory_utilization - used
-        block_bytes = 2 * hf_config.num_hidden_layers * self.block_size * hf_config.num_key_value_heads * hf_config.head_dim * hf_config.torch_dtype.itemsize
+        num_kv_heads = hf_config.num_key_value_heads // dist.get_world_size()
+        block_bytes = 2 * hf_config.num_hidden_layers * self.block_size * num_kv_heads * hf_config.head_dim * hf_config.torch_dtype.itemsize
         config.num_kvcache_blocks = int(free) // block_bytes
-        self.kv_cache = torch.zeros(2, hf_config.num_hidden_layers, config.num_kvcache_blocks, self.block_size, hf_config.num_key_value_heads, hf_config.head_dim)
+        self.kv_cache = torch.zeros(2, hf_config.num_hidden_layers, config.num_kvcache_blocks, self.block_size, num_kv_heads, hf_config.head_dim)
         layer_id = 0
         for module in self.model.modules():
             if hasattr(module, "k_cache") and hasattr(module, "v_cache"):
@@ -66,7 +124,7 @@ class ModelRunner:
         for seq in seqs:
             seqlen = len(seq)
             input_ids.extend(seq[seq.num_cached_tokens:])
-            positions.extend(list(range(seq.num_cached_tokens, len(seq))))
+            positions.extend(list(range(seq.num_cached_tokens, seqlen)))
             seqlen_q = seqlen - seq.num_cached_tokens
             seqlen_k = seqlen
             cu_seqlens_q.append(cu_seqlens_q[-1] + seqlen_q)
@@ -78,7 +136,7 @@ class ModelRunner:
                 if i != seq.num_blocks - 1:
                     end = start + self.block_size
                 else:
-                    end = start + len(seq.last_block())
+                    end = start + seq.last_block_num_tokens 
                 slot_mapping.extend(list(range(start, end)))
         assert len(input_ids) == len(slot_mapping)
         assert len(input_ids) == cu_seqlens_q[-1]
@@ -102,7 +160,7 @@ class ModelRunner:
             input_ids.append(seq.last_token)
             positions.append(len(seq))
             context_lens.append(len(seq))
-            slot_mapping.append(seq.block_table[-1] * self.block_size + len(seq.last_block()) - 1)
+            slot_mapping.append(seq.block_table[-1] * self.block_size + seq.last_block_num_tokens  - 1)
         input_ids = torch.tensor(input_ids, dtype=torch.int64, pin_memory=True).cuda(non_blocking=True)
         positions = torch.tensor(positions, dtype=torch.int64, pin_memory=True).cuda(non_blocking=True)
         slot_mapping = torch.tensor(slot_mapping, dtype=torch.int32, pin_memory=True).cuda(non_blocking=True)
@@ -148,7 +206,7 @@ class ModelRunner:
         input_ids, positions = self.prepare_prefill(seqs) if is_prefill else self.prepare_decode(seqs)
         temperatures = self.prepare_sample(seqs)
         logits = self.run_model(input_ids, positions, is_prefill)
-        token_ids = self.sampler(logits, temperatures).tolist()
+        token_ids = self.sampler(logits, temperatures).tolist() if self.rank == 0 else None
         reset_context()
         return token_ids
 
diff --git a/nanovllm/engine/scheduler.py b/nanovllm/engine/scheduler.py
index 6d1eb53..c5735fe 100644
--- a/nanovllm/engine/scheduler.py
+++ b/nanovllm/engine/scheduler.py
@@ -14,8 +14,6 @@ class Scheduler:
         self.block_manager = BlockManager(config.num_kvcache_blocks, config.kvcache_block_size)
         self.waiting: deque[Sequence] = deque()
         self.running: deque[Sequence] = deque()
-        self.num_finished = 0
-        self.num_tokens = 0
 
     def is_finished(self):
         return not self.waiting and not self.running
@@ -67,11 +65,9 @@ class Scheduler:
         self.waiting.appendleft(seq)
 
     def postprocess(self, seqs: list[Sequence], token_ids: list[int]) -> list[bool]:
-        self.num_tokens += len(token_ids)
         for seq, token_id in zip(seqs, token_ids):
             seq.append_token(token_id)
             if (not seq.ignore_eos and token_id == self.eos) or seq.num_completion_tokens == seq.max_tokens:
                 seq.status = SequenceStatus.FINISHED
                 self.block_manager.deallocate(seq)
                 self.running.remove(seq)
-                self.num_finished += 1
diff --git a/nanovllm/engine/sequence.py b/nanovllm/engine/sequence.py
index 51c0438..00866b4 100644
--- a/nanovllm/engine/sequence.py
+++ b/nanovllm/engine/sequence.py
@@ -19,15 +19,17 @@ class Sequence:
         self.seq_id = next(Sequence.counter)
         self.status = SequenceStatus.WAITING
         self.token_ids = copy(token_ids)
+        self.last_token = token_ids[-1]
+        self.num_tokens = len(self.token_ids)
         self.num_prompt_tokens = len(token_ids)
-        self._num_cached_tokens = 0
+        self.num_cached_tokens = 0
         self.block_table = []
         self.temperature = sampling_params.temperature
         self.max_tokens = sampling_params.max_tokens
         self.ignore_eos = sampling_params.ignore_eos
 
     def __len__(self):
-        return len(self.token_ids)
+        return self.num_tokens
 
     def __lt__(self, other):
         return self.seq_id < other.seq_id
@@ -41,7 +43,7 @@ class Sequence:
 
     @property
     def num_completion_tokens(self):
-        return len(self.token_ids) - self.num_prompt_tokens
+        return self.num_tokens - self.num_prompt_tokens
 
     @property
     def prompt_token_ids(self):
@@ -51,33 +53,29 @@ class Sequence:
     def completion_token_ids(self):
         return self.token_ids[self.num_prompt_tokens:]
 
-    @property
-    def num_cached_tokens(self):
-        return self._num_cached_tokens
-
-    @num_cached_tokens.setter
-    def num_cached_tokens(self, num_cached_tokens):
-        assert num_cached_tokens % self.block_size == 0
-        self._num_cached_tokens = num_cached_tokens
-
     @property
     def num_cached_blocks(self):
         return self.num_cached_tokens // self.block_size
 
     @property
     def num_blocks(self):
-        return (len(self.token_ids) + self.block_size - 1) // self.block_size
+        return (self.num_tokens + self.block_size - 1) // self.block_size
 
     @property
-    def last_token(self):
-        return self.token_ids[-1]
+    def last_block_num_tokens(self):
+        return self.num_tokens - (self.num_blocks - 1) * self.block_size
 
     def block(self, i):
+        assert 0 <= i < self.num_blocks
         return self.token_ids[i*self.block_size: (i+1)*self.block_size]
 
-    def last_block(self):
-        n = self.num_blocks
-        return self.token_ids[(n-1)*self.block_size:]
-
     def append_token(self, token_id: int):
         self.token_ids.append(token_id)
+        self.last_token = token_id
+        self.num_tokens += 1
+
+    def __getstate__(self):
+        state = vars(self).copy()
+        if self.num_completion_tokens:
+            state.pop("token_ids")
+        return state
diff --git a/nanovllm/layers/activation.py b/nanovllm/layers/activation.py
index 041ee20..8d026e1 100755
--- a/nanovllm/layers/activation.py
+++ b/nanovllm/layers/activation.py
@@ -11,4 +11,4 @@ class SiluAndMul(nn.Module):
     @torch.compile
     def forward(self, x: torch.Tensor) -> torch.Tensor:
         x, y = x.chunk(2, -1)
-        return F.silu(x) * y
+        return y.mul_(F.silu(x))
diff --git a/nanovllm/layers/embed_head.py b/nanovllm/layers/embed_head.py
index 72b6e01..6422337 100644
--- a/nanovllm/layers/embed_head.py
+++ b/nanovllm/layers/embed_head.py
@@ -14,8 +14,8 @@ class VocabParallelEmbedding(nn.Module):
         embedding_dim: int,
     ):
         super().__init__()
-        self.tp_rank = 0  # get_tensor_model_parallel_rank()
-        self.tp_size = 1  # get_tensor_model_parallel_world_size()
+        self.tp_rank = dist.get_rank()
+        self.tp_size = dist.get_world_size()
         assert num_embeddings % self.tp_size == 0
         self.num_embeddings = num_embeddings
         self.num_embeddings_per_partition = self.num_embeddings // self.tp_size
@@ -39,7 +39,7 @@ class VocabParallelEmbedding(nn.Module):
             x = mask * (x - self.vocab_start_idx)
         y = F.embedding(x, self.weight)
         if self.tp_size > 1:
-            y = mask * y
+            y = mask.unsqueeze(1) * y
             dist.all_reduce(y)
         return y
 
@@ -65,8 +65,8 @@ class ParallelLMHead(VocabParallelEmbedding):
             last_indices = context.cu_seqlens_q[1:] - 1
             x = x[last_indices].contiguous()
         logits = F.linear(x, self.weight, self.bias)
-        # if self.tp_size > 1:
-        #     all_logits = [torch.empty_like(logits) for _ in range(self.tp_size)]
-        #     dist.gather(logits, all_logits, 0)
-        #     logits = torch.cat(all_logits, -1)
-        return logits if self.tp_rank == 0 else None
\ No newline at end of file
+        if self.tp_size > 1:
+            all_logits = [torch.empty_like(logits) for _ in range(self.tp_size)] if self.tp_rank == 0 else None
+            dist.gather(logits, all_logits, 0)
+            logits = torch.cat(all_logits, -1) if self.tp_rank == 0 else None
+        return logits
diff --git a/nanovllm/layers/linear.py b/nanovllm/layers/linear.py
index d5133f1..0ae6eed 100755
--- a/nanovllm/layers/linear.py
+++ b/nanovllm/layers/linear.py
@@ -21,8 +21,8 @@ class LinearBase(nn.Module):
         self.input_size = input_size
         self.output_size = output_size
         self.tp_dim = tp_dim
-        self.tp_rank = 0  # get_tensor_model_parallel_rank()
-        self.tp_size = 1  # get_tensor_model_parallel_world_size()
+        self.tp_rank = dist.get_rank()
+        self.tp_size = dist.get_world_size()
 
     def forward(self, x: torch.Tensor) -> torch.Tensor:
         raise NotImplementedError
@@ -65,7 +65,6 @@ class ColumnParallelLinear(LinearBase):
         self.input_size_per_partition = input_size
         self.output_size_per_partition = divide(output_size, self.tp_size)
         self.output_partition_sizes = [self.output_size_per_partition]
-        # If QKV or MergedColumn, use output size of each partition.
         if hasattr(self, "output_sizes"):
             self.output_partition_sizes = [
                 divide(output_size, self.tp_size)
@@ -101,8 +100,6 @@ class MergedColumnParallelLinear(ColumnParallelLinear):
         bias: bool = False,
     ):
         self.output_sizes = output_sizes
-        tp_size = 1  # get_tensor_model_parallel_world_size()
-        assert all(output_size % tp_size == 0 for output_size in output_sizes)
         super().__init__(input_size, sum(output_sizes), bias=bias)
 
     def weight_loader(self, param: nn.Parameter, loaded_weight: torch.Tensor, loaded_shard_id: int):
@@ -110,7 +107,7 @@ class MergedColumnParallelLinear(ColumnParallelLinear):
         shard_offset = sum(self.output_sizes[:loaded_shard_id]) // self.tp_size
         shard_size = self.output_sizes[loaded_shard_id] // self.tp_size
         param_data = param_data.narrow(self.tp_dim, shard_offset, shard_size)
-        # loaded_weight = loaded_weight.narrow(self.tp_dim, self.tp_rank * shard_size, shard_size)
+        loaded_weight = loaded_weight.chunk(self.tp_size, self.tp_dim)[self.tp_rank]
         assert param_data.size() == loaded_weight.size()
         param_data.copy_(loaded_weight)
 
@@ -131,8 +128,7 @@ class QKVParallelLinear(ColumnParallelLinear):
         if total_num_kv_heads is None:
             total_num_kv_heads = total_num_heads
         self.total_num_kv_heads = total_num_kv_heads
-        # Divide the weight matrix along the last dimension.
-        tp_size = 1  # get_tensor_model_parallel_world_size()
+        tp_size = dist.get_world_size()
         self.num_heads = divide(self.total_num_heads, tp_size)
         self.num_kv_heads = divide(self.total_num_kv_heads, tp_size)
         input_size = self.hidden_size
@@ -158,7 +154,7 @@ class QKVParallelLinear(ColumnParallelLinear):
             shard_size = self.num_kv_heads * self.head_size
             shard_offset = self.num_heads * self.head_size + self.num_kv_heads * self.head_size
         param_data = param_data.narrow(self.tp_dim, shard_offset, shard_size)
-        # loaded_weight = loaded_weight.narrow(self.tp_dim, self.tp_rank * shard_size, shard_size)
+        loaded_weight = loaded_weight.chunk(self.tp_size, self.tp_dim)[self.tp_rank]
         assert param_data.size() == loaded_weight.size()
         param_data.copy_(loaded_weight)
 
diff --git a/nanovllm/layers/rotary_embedding.py b/nanovllm/layers/rotary_embedding.py
index 26ca5f9..1f483e7 100644
--- a/nanovllm/layers/rotary_embedding.py
+++ b/nanovllm/layers/rotary_embedding.py
@@ -70,4 +70,4 @@ def get_rope(
 ):
     assert rope_scaling is None
     rotary_emb = RotaryEmbedding(head_size, rotary_dim, max_position, base)
-    return rotary_emb
\ No newline at end of file
+    return rotary_emb
diff --git a/nanovllm/llm.py b/nanovllm/llm.py
index 1c3efe9..4f51a44 100644
--- a/nanovllm/llm.py
+++ b/nanovllm/llm.py
@@ -2,4 +2,4 @@ from nanovllm.engine.llm_engine import LLMEngine
 
 
 class LLM(LLMEngine):
-    pass
\ No newline at end of file
+    pass
diff --git a/nanovllm/models/qwen3.py b/nanovllm/models/qwen3.py
index f65475f..c306be5 100755
--- a/nanovllm/models/qwen3.py
+++ b/nanovllm/models/qwen3.py
@@ -1,5 +1,6 @@
 import torch
 from torch import nn
+import torch.distributed as dist
 from transformers import Qwen3Config
 
 from nanovllm.layers.activation import SiluAndMul
@@ -26,7 +27,7 @@ class Qwen3Attention(nn.Module):
     ) -> None:
         super().__init__()
         self.hidden_size = hidden_size
-        tp_size = 1  # get_tensor_model_parallel_world_size()
+        tp_size = dist.get_world_size()
         self.total_num_heads = num_heads
         assert self.total_num_heads % tp_size == 0
         self.num_heads = self.total_num_heads // tp_size
diff --git a/nanovllm/utils/context.py b/nanovllm/utils/context.py
index d4cfd3d..65bbd18 100644
--- a/nanovllm/utils/context.py
+++ b/nanovllm/utils/context.py
@@ -25,4 +25,4 @@ def set_context(is_prefill, cu_seqlens_q=None, cu_seqlens_k=None, max_seqlen_q=0
 
 def reset_context():
     global _CONTEXT
-    _CONTEXT = Context()
\ No newline at end of file
+    _CONTEXT = Context()
diff --git a/nanovllm/utils/loader.py b/nanovllm/utils/loader.py
index c052e0f..4ef8040 100644
--- a/nanovllm/utils/loader.py
+++ b/nanovllm/utils/loader.py
@@ -10,7 +10,6 @@ def default_weight_loader(param: nn.Parameter, loaded_weight: torch.Tensor):
 
 
 def load_model(model: nn.Module, path: str):
-    assert os.path.isdir(path)
     packed_modules_mapping = getattr(model, "packed_modules_mapping", {})
     for file in glob(os.path.join(path, "*.safetensors")):
         with safe_open(file, "pt", "cpu") as f:
diff --git a/pyproject.toml b/pyproject.toml
index efb424b..bf3ecda 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "nano-vllm"
-version = "0.1.0"
+version = "0.2.0"
 authors = [{ name = "Xingkai Yu" }]
 license = "MIT"
 license-files = ["LICENSE"]