Add test for Mixtral model. (#131)

* Add test for Mixtral model.

* Fix per comments.

Author: wang2yn84

jetstream_pt/third_party/mixtral/config.py

@@ -75,4 +75,15 @@ def from_name(cls, name: str):
         num_experts=8,
         num_activated_experts=2,
     ),
+    "Mixtral-tiny": dict(
+        block_size=128,
+        n_layer=3,
+        n_head=32,
+        n_local_heads=8,
+        dim=128,
+        intermediate_size=None,
+        rope_base=1000000.0,
+        num_experts=8,
+        num_activated_experts=2,
+    ),
 }

jetstream_pt/third_party/mixtral/model_original.py

@@ -23,6 +23,12 @@
 from .config import ModelArgs, find_multiple
 
 
+def find_multiple(n: int, k: int) -> int:
+  if n % k == 0:
+    return n
+  return n + k - (n % k)
+
+
 class KVCache(nn.Module):
 
   def __init__(
@@ -31,7 +37,8 @@ def __init__(
       max_seq_length,
       n_heads,
       head_dim,
-      dtype=torch.bfloat16,
+      # dtype=torch.bfloat16,
+      dtype=torch.float32,
   ):
     super().__init__()
     cache_shape = (max_batch_size, n_heads, max_seq_length, head_dim)
@@ -191,22 +198,21 @@ class ConditionalFeedForward(nn.Module):
 
   def __init__(self, config):
     super().__init__()
+    # Replace the weight init of torch.empty with torch.rand for testing purpose
     self.w1 = nn.Parameter(
-        torch.empty(config.num_experts, config.intermediate_size, config.dim)
+        torch.rand(config.num_experts, config.intermediate_size, config.dim)
     )
     self.w2 = nn.Parameter(
-        torch.empty(config.num_experts, config.dim, config.intermediate_size)
+        torch.rand(config.num_experts, config.dim, config.intermediate_size)
     )
     self.w3 = nn.Parameter(
-        torch.empty(config.num_experts, config.intermediate_size, config.dim)
+        torch.rand(config.num_experts, config.intermediate_size, config.dim)
     )
 
   def forward(self, x: Tensor, expert_indices: Tensor) -> Tensor:
-    # T = num_tokens, I = intermediate size, D = hidden dim, A = activated experts
     w1_weights = self.w1[expert_indices]  # [T, A, D, D]
     w3_weights = self.w3[expert_indices]  # [T, A, D, D]
     w2_weights = self.w2[expert_indices]  # [T, A, D, D]
-    # x: [T, D]
     x1 = F.silu(torch.einsum("ti,taoi -> tao", x, w1_weights))
     x3 = torch.einsum("ti, taoi -> tao", x, w3_weights)
     expert_outs = torch.einsum("tao, taio -> tai", (x1 * x3), w2_weights)
@@ -215,7 +221,7 @@ def forward(self, x: Tensor, expert_indices: Tensor) -> Tensor:
 
 class MOEFeedForward(nn.Module):
 
-  def __init__(self, config, env=None) -> None:
+  def __init__(self, config) -> None:
     super().__init__()
     self.gate = nn.Linear(config.dim, config.num_experts, bias=False)
     self.cond_ffn = ConditionalFeedForward(config)
@@ -261,7 +267,8 @@ def precompute_freqs_cis(
   freqs = torch.outer(t, freqs)
   freqs_cis = torch.polar(torch.ones_like(freqs), freqs)
   cache = torch.stack([freqs_cis.real, freqs_cis.imag], dim=-1)
-  return cache.to(dtype=torch.bfloat16)
+  # return cache.to(dtype=torch.bfloat16)
+  return cache
 
 
 def apply_rotary_emb(x: Tensor, freqs_cis: Tensor) -> Tensor:

tests/helpers.py

@@ -1,8 +1,8 @@
 import jax
 import torch
 import torch_xla2
-import jax
 from jetstream_pt.third_party.llama import model_args
+from jetstream_pt.third_party.mixtral import config as mixtral_config
 from jetstream_pt import environment
 
 
@@ -31,13 +31,38 @@ def make_env_tiny(bf16_enable=True):
   return env, config
 
 
+def make_mixtral_env(bf16_enable=True):
+  torch_dtype = torch.bfloat16 if bf16_enable else torch.float32
+  torch.set_default_dtype(torch_dtype)
+  jax.config.update("jax_dynamic_shapes", False)
+  jax.config.update("jax_traceback_filtering", "off")
+  config = mixtral_config.ModelArgs.from_name("Mixtral-tiny")
+  environment_data = environment.JetEngineEnvironmentData()
+  environment_data.max_input_sequence_length = 128
+  environment_data.cache_sequence_length = 128
+  environment_data.bf16_enable = bf16_enable
+  environment_data.model_type = "mixtral"
+  environment_data.batch_size = 1
+  environment_data.num_layers = config.n_layer
+  environment_data.cache_shape = (
+      1,
+      config.n_local_heads,
+      environment_data.cache_sequence_length,
+      config.dim // config.n_head,
+  )
+  env = environment.JetEngineEnvironment(environment_data)
+  env.apply_sharding = lambda *args, **kwargs: None  # don't shard on cpu
+  return env, config
+
+
 def to_xla_tensor(tree):
   return torch_xla2.default_env().to_xla(tree)
 
 
 def call_xla_model(model, weights, args):
   with jax.default_device(jax.devices("cpu")[0]):
     xla_weights, xla_inputs = to_xla_tensor((weights, args))
-    result = torch.func.functional_call(model, xla_weights, xla_inputs)
+    with torch_xla2.default_env():
+      result = torch.func.functional_call(model, xla_weights, xla_inputs)
     result_torch = torch_xla2.tensor.j2t(result._elem)
     return result_torch

tests/test_model_impl.py

@@ -23,6 +23,7 @@
 from jetstream_pt.third_party.llama import model_original
 from jetstream_pt.third_party.gemma import model_original as gemma_orig
 from jetstream_pt.third_party.gemma import model as gemma
+from jetstream_pt.third_party.mixtral import model_original as mixtral_orig
 from jetstream_pt.third_party.mixtral import model as mixtral
 from jetstream_pt.third_party.mixtral import config as mixtral_config
 from jetstream_pt import torchjax
@@ -362,6 +363,68 @@ def test_transformer(self):
     print("Transformer: Diff norm", (result_torch - expected_out).norm())
     self.assertTrue(torch.allclose(result_torch, expected_out, atol=1e-4))
 
+  # pylint: disable-next=all
+  def test_mixtral_transformer(self):
+    """test transformer diff between original model vs xla_model"""
+    env, model_arg = helpers.make_mixtral_env(False)
+
+    model_orig = mixtral_orig.Transformer(model_arg)
+    model_orig.setup_caches(max_batch_size=1, max_seq_length=env.cache_len)
+
+    state_dict = dict(model_orig.state_dict())
+    state_dict["freqs_cis"] = model_orig.freqs_cis
+    new_dict = {}
+
+    for k, v in state_dict.items():
+      if "kv_cache" in k:
+        continue
+      if "wqkv" in k:
+        wq = k.replace("wqkv", "wq")
+        wk = k.replace("wqkv", "wk")
+        wv = k.replace("wqkv", "wv")
+        kv_size = model_arg.n_local_heads * model_arg.head_dim
+        wq_t, wk_t, wv_t = v.split([model_arg.dim, kv_size, kv_size], dim=0)
+
+        new_dict[wq] = wq_t
+        new_dict[wk] = wk_t
+        new_dict[wv] = wv_t
+        continue
+      # "Freqs_cis" for exported model is calculated differently, by complex data type
+      if "freqs_cis" in k:
+        new_dict[k] = mixtral.precompute_freqs_cis(
+            model_arg.block_size,
+            model_arg.dim // model_arg.n_head,
+            model_arg.rope_base,
+        )
+        continue
+      new_dict[k] = v
+
+    model_ours = mixtral.Transformer(model_arg, env)
+
+    # Invoke original model
+    seqlen = 32
+    x = torch.randint(0, 32000, (1, seqlen))  # (batch, seqlen, embedding dim)
+    start_pos = 0
+    mask = self._prefill_mask(seqlen, start_pos)
+    input_pos = torch.arange(0, seqlen)
+    inputs_orig = (x, input_pos)
+
+    expected_out = model_orig(*inputs_orig)
+
+    # Invoke the exported model
+    caches = env.make_caches_prefill()
+
+    input_ours = (
+        x,
+        input_pos,
+        caches,
+        mask,
+    )
+    result_torch = helpers.call_xla_model(model_ours, new_dict, input_ours)
+
+    print("Transformer: Diff norm", (result_torch - expected_out).norm())
+    self.assertTrue(torch.allclose(result_torch, expected_out, atol=1e-4))
+
   def test_mixtral_moe(self):
     config = mixtral_config.ModelArgs()
     config.intermediate_size = 16