Support Llama-3.1-405B (#199)

* Support Llama 3.1 405B

* Update readme

Author: yanboliang

README.md

@@ -73,6 +73,7 @@ mistralai/Mistral-7B-v0.1
 mistralai/Mistral-7B-Instruct-v0.1
 mistralai/Mistral-7B-Instruct-v0.2
 meta-llama/Meta-Llama-3-8B
+meta-llama/Meta-Llama-3.1-405B
 ```
 
 For example, to convert Llama-2-7b-chat-hf
@@ -120,6 +121,7 @@ Benchmarks run on an 8xA100-80GB, power limited to 330W with a hybrid cube mesh
 | Llama-2-70B | Base    | 62.50     | 1135.29 |
 |           | 8-bit   | 80.44    | 752.04 |
 |           | 4-bit (G=32)   | 90.77    | 548.10 |
+| Llama-3.1-405B | 8-bit | 15.60 | 815.87 |
 
 ### AMD
 Benchmarks run on one GCD of a MI-250x.

model.py

@@ -3,6 +3,7 @@
 
 # This source code is licensed under the license found in the
 # LICENSE file in the root directory of this source tree.
+import math
 from dataclasses import dataclass
 from typing import Optional
 
@@ -29,6 +30,7 @@ class ModelArgs:
     head_dim: int = 64
     rope_base: float = 10000
     norm_eps: float = 1e-5
+    rope_scaling: Optional[dict] = None
 
     def __post_init__(self):
         if self.n_local_heads == -1:
@@ -68,6 +70,9 @@ def from_name(cls, name: str):
 
     "llama-3-8b": dict(block_size=8192, n_layer=32, n_head=32, n_local_heads=8, dim=4096, intermediate_size=14336, vocab_size=128256, rope_base=500000),
     "llama-3-70b": dict(block_size=8192, n_layer=80, n_head=64, n_local_heads=8, dim=8192, intermediate_size=28672, vocab_size=128256, rope_base=500000),
+    "llama-3.1-405b": dict(block_size=131072, n_layer=126, n_head=128, n_local_heads=8, dim=16384, intermediate_size=53248, vocab_size=128256, rope_base=500000,
+        rope_scaling=dict(factor=8.0, low_freq_factor=1.0, high_freq_factor=4.0, original_max_position_embeddings=8192),
+    ),
 }
 
 class KVCache(nn.Module):
@@ -119,7 +124,7 @@ def setup_caches(self, max_batch_size, max_seq_length):
         for b in self.layers:
             b.attention.kv_cache = KVCache(max_batch_size, max_seq_length, self.config.n_local_heads, head_dim, dtype)
 
-        self.freqs_cis = precompute_freqs_cis(self.config.block_size, self.config.dim // self.config.n_head, self.config.rope_base, dtype)
+        self.freqs_cis = precompute_freqs_cis(self.config.block_size, self.config.dim // self.config.n_head, self.config.rope_base, dtype, self.config.rope_scaling)
         self.causal_mask = torch.tril(torch.ones(self.max_seq_length, self.max_seq_length, dtype=torch.bool))
 
     def forward(self, idx: Tensor, input_pos: Optional[Tensor] = None) -> Tensor:
@@ -230,11 +235,36 @@ def forward(self, x: Tensor) -> Tensor:
         return output * self.weight
 
 
+def apply_rope_scaling(freqs: torch.Tensor, rope_scaling: Optional[dict] = None):
+    factor = rope_scaling["factor"]
+    low_freq_factor = rope_scaling["low_freq_factor"]
+    high_freq_factor = rope_scaling["high_freq_factor"]
+    old_context_len = rope_scaling["original_max_position_embeddings"]
+
+    low_freq_wavelen = old_context_len / low_freq_factor
+    high_freq_wavelen = old_context_len / high_freq_factor
+    new_freqs = []
+    for freq in freqs:
+        wavelen = 2 * math.pi / freq
+        if wavelen < high_freq_wavelen:
+            new_freqs.append(freq)
+        elif wavelen > low_freq_wavelen:
+            new_freqs.append(freq / factor)
+        else:
+            assert low_freq_wavelen != high_freq_wavelen
+            smooth = (old_context_len / wavelen - low_freq_factor) / (high_freq_factor - low_freq_factor)
+            new_freqs.append((1 - smooth) * freq / factor + smooth * freq)
+    return torch.tensor(new_freqs, dtype=freqs.dtype, device=freqs.device)
+
+
 def precompute_freqs_cis(
     seq_len: int, n_elem: int, base: int = 10000,
-    dtype: torch.dtype = torch.bfloat16
+    dtype: torch.dtype = torch.bfloat16,
+    rope_scaling: Optional[dict] = None,
 ) -> Tensor:
     freqs = 1.0 / (base ** (torch.arange(0, n_elem, 2)[: (n_elem // 2)].float() / n_elem))
+    if rope_scaling is not None:
+        freqs = apply_rope_scaling(freqs, rope_scaling)
     t = torch.arange(seq_len, device=freqs.device)
     freqs = torch.outer(t, freqs)
     freqs_cis = torch.polar(torch.ones_like(freqs), freqs)

scripts/convert_hf_checkpoint.py

@@ -116,7 +116,10 @@ def permute(w, n_head):
     print(f"Saving checkpoint to {checkpoint_dir / 'model.pth'}")
     torch.save(final_result, checkpoint_dir / "model.pth")
     if 'llama-3' in model_name.lower():
-        original_dir = checkpoint_dir / "original"
+        if 'llama-3.1' in model_name.lower():
+            original_dir = checkpoint_dir / "original" / "mp16"
+        else:
+            original_dir = checkpoint_dir / "original"
         tokenizer_model = original_dir / "tokenizer.model"
         tokenizer_model_tiktoken = checkpoint_dir / "tokenizer.model"
         print(f"Copying {tokenizer_model} to {tokenizer_model_tiktoken}")