Merge branch 'main' into leo/load-layers-individually

src/exo/worker/engines/mlx/auto_parallel.py

@@ -1,7 +1,10 @@
+import os
+import threading
 from abc import ABC, abstractmethod
+from collections.abc import Callable
 from functools import partial
 from inspect import signature
-from typing import TYPE_CHECKING, Callable, Protocol, cast
+from typing import TYPE_CHECKING, Any, Protocol, cast
 
 import mlx.core as mx
 import mlx.nn as nn
@@ -29,6 +32,40 @@ from mlx_lm.models.qwen3_next import Qwen3NextSparseMoeBlock
 from exo.shared.logging import logger
 from exo.shared.types.worker.shards import PipelineShardMetadata
 
+TimeoutCallback = Callable[[], None]
+
+
+def eval_with_timeout(
+    mlx_item: Any,  # pyright: ignore[reportAny]
+    timeout_seconds: float = 60.0,
+    on_timeout: TimeoutCallback | None = None,
+) -> None:
+    """Evaluate MLX item with a hard timeout.
+
+    If on_timeout callback is provided, it will be called before terminating
+    the process. This allows the runner to send a failure event before exit.
+    """
+    completed = threading.Event()
+
+    def watchdog() -> None:
+        if not completed.wait(timeout=timeout_seconds):
+            logger.error(
+                f"mlx_item evaluation timed out after {timeout_seconds:.0f}s. "
+                "This may indicate an issue with FAST_SYNCH and tensor parallel sharding. "
+                "Terminating process."
+            )
+            if on_timeout is not None:
+                on_timeout()
+            os._exit(1)
+
+    watchdog_thread = threading.Thread(target=watchdog, daemon=True)
+    watchdog_thread.start()
+
+    try:
+        mx.eval(mlx_item)  # pyright: ignore[reportAny]
+    finally:
+        completed.set()
+
 
 class _LayerCallable(Protocol):
     """Structural type that any compatible layer must satisfy.
@@ -225,9 +262,37 @@ def patch_pipeline_model[T](model: T, group: mx.distributed.Group) -> T:
     return model
 
 
+def patch_tensor_model[T](model: T) -> T:
+    """Patch model's __call__ to ensure distributed ops sync during inference."""
+    cls = model.__class__
+    original_call = cls.__call__
+    call_signature = signature(original_call)
+
+    def patched_call(
+        self: T,
+        *args: object,
+        **kwargs: object,
+    ) -> mx.array:
+        logits: mx.array = original_call(self, *args, **kwargs)  # pyright: ignore[reportAny]
+        cache = call_signature.bind_partial(self, *args, **kwargs).arguments.get(
+            "cache", None
+        )
+
+        # Add dependency to last cache entry to ensure distributed ops are evaluated
+        if cache is not None and len(cache) > 0:  # pyright: ignore[reportAny]
+            cache[-1].state = mx.depends(cache[-1].state, logits)  # pyright: ignore[reportAny,reportUnknownMemberType]
+
+        return logits
+
+    cls.__call__ = patched_call
+    return model
+
+
 def tensor_auto_parallel(
     model: nn.Module,
     group: mx.distributed.Group,
+    timeout_seconds: float = 60.0,
+    on_timeout: TimeoutCallback | None = None,
 ) -> nn.Module:
     all_to_sharded_linear = partial(
         shard_linear,
@@ -272,7 +337,7 @@ def tensor_auto_parallel(
     if hasattr(model, "shard"):
         try:
             model.shard(group)  # type: ignore
-            return model
+            return patch_tensor_model(model)
         except (AttributeError, TypeError, NameError):
             pass
 
@@ -322,7 +387,10 @@ def tensor_auto_parallel(
     else:
         raise ValueError(f"Unsupported model type: {type(model)}")
 
-    return tensor_parallel_sharding_strategy.shard_model(model)
+    model = tensor_parallel_sharding_strategy.shard_model(
+        model, timeout_seconds, on_timeout
+    )
+    return patch_tensor_model(model)
 
 
 class TensorParallelShardingStrategy(ABC):
@@ -342,13 +410,27 @@ class TensorParallelShardingStrategy(ABC):
         self.N = group.size()
 
     @abstractmethod
-    def shard_model(self, model: nn.Module) -> nn.Module: ...
+    def shard_model(
+        self,
+        model: nn.Module,
+        timeout_seconds: float,
+        on_timeout: TimeoutCallback | None,
+    ) -> nn.Module: ...
 
 
 class LlamaShardingStrategy(TensorParallelShardingStrategy):
-    def shard_model(self, model: nn.Module) -> nn.Module:
+    def shard_model(
+        self,
+        model: nn.Module,
+        timeout_seconds: float,
+        on_timeout: TimeoutCallback | None,
+    ) -> nn.Module:
         model = cast(LlamaModel, model)
         for layer in model.layers:
+            # Force load weights before sharding to avoid FAST_SYNCH deadlock
+            eval_with_timeout(
+                layer.parameters(), timeout_seconds / len(model.layers), on_timeout
+            )
             layer.self_attn.q_proj = self.all_to_sharded_linear(layer.self_attn.q_proj)
             layer.self_attn.k_proj = self.all_to_sharded_linear(layer.self_attn.k_proj)
             layer.self_attn.v_proj = self.all_to_sharded_linear(layer.self_attn.v_proj)
@@ -391,9 +473,17 @@ def _set_layers(model: nn.Module, layers: list[_LayerCallable]) -> None:
 
 
 class DeepSeekShardingStrategy(TensorParallelShardingStrategy):
-    def shard_model(self, model: nn.Module) -> nn.Module:
+    def shard_model(
+        self,
+        model: nn.Module,
+        timeout_seconds: float,
+        on_timeout: TimeoutCallback | None,
+    ) -> nn.Module:
         model = cast(DeepseekV3Model, model)
         for layer in model.layers:
+            eval_with_timeout(
+                layer.parameters(), timeout_seconds / len(model.layers), on_timeout
+            )
             # Shard the self attention
             if layer.self_attn.q_lora_rank is None:
                 layer.self_attn.q_proj = self.all_to_sharded_linear(
@@ -445,9 +535,17 @@ class ShardedDeepseekV3MoE(CustomMlxLayer):
 
 
 class MiniMaxShardingStrategy(TensorParallelShardingStrategy):
-    def shard_model(self, model: nn.Module) -> nn.Module:
+    def shard_model(
+        self,
+        model: nn.Module,
+        timeout_seconds: float,
+        on_timeout: TimeoutCallback | None,
+    ) -> nn.Module:
         model = cast(MiniMaxModel, model)
         for layer in model.layers:
+            eval_with_timeout(
+                layer.parameters(), timeout_seconds / len(model.layers), on_timeout
+            )
             # Shard the self attention
             layer.self_attn.q_proj = self.all_to_sharded_linear(layer.self_attn.q_proj)
             layer.self_attn.k_proj = self.all_to_sharded_linear(layer.self_attn.k_proj)
@@ -474,9 +572,17 @@ class MiniMaxShardingStrategy(TensorParallelShardingStrategy):
 
 
 class QwenShardingStrategy(TensorParallelShardingStrategy):
-    def shard_model(self, model: nn.Module) -> nn.Module:
+    def shard_model(
+        self,
+        model: nn.Module,
+        timeout_seconds: float,
+        on_timeout: TimeoutCallback | None,
+    ) -> nn.Module:
         model = cast(Qwen3MoeModel, model)
         for layer in model.layers:
+            eval_with_timeout(
+                layer.parameters(), timeout_seconds / len(model.layers), on_timeout
+            )
             # Shard the self attention
             layer.self_attn.q_proj = self.all_to_sharded_linear(layer.self_attn.q_proj)
             layer.self_attn.k_proj = self.all_to_sharded_linear(layer.self_attn.k_proj)
@@ -520,10 +626,18 @@ class ShardedQwenMoE(CustomMlxLayer):
 
 
 class GptOssShardingStrategy(TensorParallelShardingStrategy):
-    def shard_model(self, model: nn.Module) -> nn.Module:
+    def shard_model(
+        self,
+        model: nn.Module,
+        timeout_seconds: float,
+        on_timeout: TimeoutCallback | None,
+    ) -> nn.Module:
         model = cast(GptOssMoeModel, model)
 
         for layer in model.layers:
+            eval_with_timeout(
+                layer.parameters(), timeout_seconds / len(model.layers), on_timeout
+            )
             layer.self_attn.q_proj = self.all_to_sharded_linear(layer.self_attn.q_proj)
             layer.self_attn.k_proj = self.all_to_sharded_linear(layer.self_attn.k_proj)
             layer.self_attn.v_proj = self.all_to_sharded_linear(layer.self_attn.v_proj)

src/exo/worker/engines/mlx/utils_mlx.py

@@ -2,9 +2,7 @@ import json
 import os
 import resource
 import sys
-import threading
 import time
-from collections.abc import Callable
 from pathlib import Path
 from typing import Any, cast
 
@@ -59,6 +57,8 @@ from exo.shared.types.worker.shards import (
 from exo.worker.download.download_utils import build_model_path
 from exo.worker.engines.mlx import Model
 from exo.worker.engines.mlx.auto_parallel import (
+    TimeoutCallback,
+    eval_with_timeout,
     pipeline_auto_parallel,
     tensor_auto_parallel,
 )
@@ -88,41 +88,6 @@ class ModelLoadingTimeoutError(Exception):
     pass
 
 
-TimeoutCallback = Callable[[], None]
-
-
-def eval_with_timeout(
-    mlx_item: Any,  # pyright: ignore[reportAny]
-    timeout_seconds: float = 60.0,
-    on_timeout: TimeoutCallback | None = None,
-) -> None:
-    """Evaluate MLX item with a hard timeout.
-
-    If on_timeout callback is provided, it will be called before terminating
-    the process. This allows the runner to send a failure event before exit.
-    """
-    completed = threading.Event()
-
-    def watchdog() -> None:
-        if not completed.wait(timeout=timeout_seconds):
-            logger.error(
-                f"mlx_item evaluation timed out after {timeout_seconds:.0f}s. "
-                "This may indicate an issue with FAST_SYNCH and tensor parallel sharding. "
-                "Terminating process."
-            )
-            if on_timeout is not None:
-                on_timeout()
-            os._exit(1)
-
-    watchdog_thread = threading.Thread(target=watchdog, daemon=True)
-    watchdog_thread.start()
-
-    try:
-        mx.eval(mlx_item)  # pyright: ignore[reportAny]
-    finally:
-        completed.set()
-
-
 def mx_barrier(group: Group | None = None):
     mx.eval(
         mx.distributed.all_sum(
@@ -296,14 +261,6 @@ def shard_and_load(
 
     logger.info(f"Group size: {group.size()}, group rank: {group.rank()}")
 
-    match shard_metadata:
-        case TensorShardMetadata():
-            logger.info(f"loading model from {model_path} with tensor parallelism")
-            model = tensor_auto_parallel(model, group)
-        case PipelineShardMetadata():
-            logger.info(f"loading model from {model_path} with pipeline parallelism")
-            model = pipeline_auto_parallel(model, group, shard_metadata)
-
     # Estimate timeout based on model size
     base_timeout = float(os.environ.get("EXO_MODEL_LOAD_TIMEOUT", "60"))
     model_size_gb = get_weights_size(shard_metadata).in_bytes / (1024**3)
@@ -312,7 +269,15 @@ def shard_and_load(
         f"Evaluating model parameters with timeout of {timeout_seconds:.0f}s "
         f"(model size: {model_size_gb:.1f}GB)"
     )
-    eval_with_timeout(model.parameters(), timeout_seconds, on_timeout)
+
+    match shard_metadata:
+        case TensorShardMetadata():
+            logger.info(f"loading model from {model_path} with tensor parallelism")
+            model = tensor_auto_parallel(model, group, timeout_seconds, on_timeout)
+        case PipelineShardMetadata():
+            logger.info(f"loading model from {model_path} with pipeline parallelism")
+            model = pipeline_auto_parallel(model, group, shard_metadata)
+            eval_with_timeout(model.parameters(), timeout_seconds, on_timeout)
 
     # TODO: Do we need this?
     mx.eval(model)