add unit tests for cum seq lens, add ability to build cu_seq_lens from positional ids, fix prompt test

src/axolotl/monkeypatch/llama_attn_hijack_flash.py

@@ -17,47 +17,7 @@ except ImportError:
 
 from transformers.models.llama.modeling_llama import apply_rotary_pos_emb
 
-
-def get_cu_seqlens(attn_mask):
-    device = attn_mask.device
-    # Exclude zeros to avoid adding their positions to the mask
-    t_non_zeros = attn_mask[attn_mask != 0]
-    # Find where the sequence number changes (including the first position)
-    seq_change = torch.cat(
-        [
-            torch.tensor([1], dtype=torch.int32, device=device),
-            t_non_zeros[1:] != t_non_zeros[:-1],
-        ]
-    )
-    # Get the indices where the sequence changes
-    change_indices = torch.cat(
-        [
-            (seq_change == 1).nonzero(as_tuple=True)[0],
-            torch.tensor([len(t_non_zeros)], dtype=torch.int32, device=device),
-        ]
-    )
-    # Calculate the sequence lengths
-    seq_lengths = change_indices[1:] - change_indices[:-1]
-    # Calculate the length of the final sequence or padding
-    final_seq_length = attn_mask.shape[1] - change_indices[-1]
-    # Append the length of the final sequence or padding to seq_lengths
-    if final_seq_length.item():
-        seq_lengths = torch.cat(
-            [
-                seq_lengths,
-                torch.tensor(
-                    [final_seq_length.item()], dtype=torch.int32, device=device
-                ),
-            ]
-        )
-    # Calculate the cumulative sequence lengths
-    cu_seqlens = torch.cat(
-        [torch.tensor([0], dtype=torch.int32, device=device), seq_lengths.cumsum(0)]
-    )
-
-    max_seq_len = (cu_seqlens[1:] - cu_seqlens[:-1]).max()
-
-    return cu_seqlens.to(dtype=torch.int32), max_seq_len
+from axolotl.monkeypatch.utils import get_cu_seqlens
 
 
 def forward(

src/axolotl/monkeypatch/utils.py

@@ -0,0 +1,103 @@
+"""
+Shared utils for the monkeypatches
+"""
+import torch
+
+
+def get_cu_seqlens(attn_mask):
+    """generate a cumulative sequence length mask for flash attention using attn mask"""
+    if len(attn_mask.shape) == 1:
+        attn_mask = attn_mask.unsqueeze(0)
+
+    device = attn_mask.device
+    results = []
+    max_seq_lens = []
+
+    for row in attn_mask:
+        # Exclude zeros to avoid adding their positions to the mask
+        t_non_zeros = row[row != 0]
+        # Find where the sequence number changes (including the first position)
+        seq_change = torch.cat(
+            [
+                torch.tensor([1], dtype=torch.int32, device=device),
+                t_non_zeros[1:] != t_non_zeros[:-1],
+            ]
+        )
+        # Get the indices where the sequence changes
+        change_indices = torch.cat(
+            [
+                (seq_change == 1).nonzero(as_tuple=True)[0],
+                torch.tensor([len(t_non_zeros)], dtype=torch.int32, device=device),
+            ]
+        )
+        # Calculate the sequence lengths
+        seq_lengths = change_indices[1:] - change_indices[:-1]
+        # Calculate the length of the final sequence or padding
+        final_seq_length = len(row) - change_indices[-1]
+        # Append the length of the final sequence or padding to seq_lengths
+        if final_seq_length.item():
+            seq_lengths = torch.cat(
+                [
+                    seq_lengths,
+                    torch.tensor(
+                        [final_seq_length.item()], dtype=torch.int32, device=device
+                    ),
+                ]
+            )
+        # Calculate the cumulative sequence lengths
+        cu_seqlens = torch.cat(
+            [torch.tensor([0], dtype=torch.int32, device=device), seq_lengths.cumsum(0)]
+        )
+        max_seq_len = (cu_seqlens[1:] - cu_seqlens[:-1]).max()
+        results.append(cu_seqlens)
+        max_seq_lens.append(max_seq_len)
+
+    return torch.stack(results).to(dtype=torch.int32), torch.stack(max_seq_lens)
+
+
+def get_cu_seqlens_from_pos_ids(position_ids):
+    """generate a cumulative sequence length mask for flash attention using pos ids"""
+    if len(position_ids.shape) == 1:
+        position_ids = position_ids.unsqueeze(0)
+
+    device = position_ids.device
+    results = []
+    max_seq_lens = []
+
+    for row in position_ids:
+        # Count the number of consecutive zeros from the right side
+        padding_length = (row == 0).int().flip(dims=[0]).cumprod(dim=0).sum().item()
+
+        # Adjust the row to exclude padding
+        adjusted_row = row[:-padding_length] if padding_length else row.clone()
+
+        # Find where the position resets to 0 (indicating a new sequence)
+        seq_starts = torch.cat(
+            [
+                torch.tensor([True], dtype=torch.bool, device=device),
+                adjusted_row[1:] == 0,
+            ]
+        )
+        # Get the indices where the sequence starts
+        start_indices = torch.cat(
+            [
+                (seq_starts).nonzero(as_tuple=True)[0],
+                torch.tensor([len(adjusted_row)], dtype=torch.int32, device=device),
+            ]
+        )
+        # Calculate the sequence lengths
+        seq_lengths = start_indices[1:] - start_indices[:-1]
+        # Calculate the cumulative sequence lengths
+        cu_seqlens = torch.cat(
+            [torch.tensor([0], dtype=torch.int32, device=device), seq_lengths.cumsum(0)]
+        )
+        # Append the padding length to the cumulative sequence lengths
+        if padding_length:
+            cu_seqlens = torch.cat(
+                [cu_seqlens, torch.tensor([len(row)], dtype=torch.int32, device=device)]
+            )
+        max_seq_len = (cu_seqlens[1:] - cu_seqlens[:-1]).max()
+        results.append(cu_seqlens)
+        max_seq_lens.append(max_seq_len)
+
+    return torch.stack(results).to(dtype=torch.int32), torch.stack(max_seq_lens)

src/axolotl/prompters.py

@@ -45,7 +45,7 @@ class AlpacaPrompter:
         if self.prompt_style == PromptStyle.CHAT.value:
             self.turn_format = "USER: {instruction}\n{input}\nASSISTANT:"
             self.turn_no_input_format = "USER: {instruction}\nASSISTANT:"
-            self.system_format = "SYSTEM:{system}\n"
+            self.system_format = "SYSTEM: {system}\n"
         if self.prompt_style == PromptStyle.CHATML.value:
             self.turn_format = "<|im_start|>user\n{instruction}\n{input}<|im_end|>\n<|im_start|>assistant\n"
             self.turn_no_input_format = (

tests/monkeypatch/test_llama_attn_hijack_flash.py

@@ -0,0 +1,30 @@
+"""
+Unit tests for the monkeypatch utils
+"""
+import unittest
+
+import torch
+
+from axolotl.monkeypatch.utils import get_cu_seqlens, get_cu_seqlens_from_pos_ids
+
+
+class TestMonkeyPatchUtils(unittest.TestCase):
+    """
+    Unit test class for monkeypatch utils
+    """
+
+    def test_get_cu_seqlens_1d(self):
+        attn_mask = torch.tensor([[1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 0, 0]])
+        target_res = torch.tensor([0, 4, 7, 12, 14, 16], dtype=torch.int32)
+        self.assertTrue(torch.allclose(get_cu_seqlens(attn_mask)[0], target_res))
+
+    def test_get_cu_seqlens_from_pos_ids_1d(self):
+        position_ids = torch.tensor([[0, 1, 2, 3, 0, 1, 2, 0, 1, 2, 3, 4, 0, 1, 0, 0]])
+        target_res = torch.tensor([0, 4, 7, 12, 14, 16], dtype=torch.int32)
+        self.assertTrue(
+            torch.allclose(get_cu_seqlens_from_pos_ids(position_ids)[0], target_res)
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_prompt_tokenizers.py

@@ -134,9 +134,15 @@ class InstructionWSystemPromptTokenizingStrategyTest(unittest.TestCase):
             "output": "Hi! How can I help?",
         }
         example = strat.tokenize_prompt(sample)
-        assert example["input_ids"][0:4] == [1, 835, 2184, 29901]  # "<s>### System:"
-        assert example["input_ids"][5:7] == [1509, 20118]  # "use cot"
-        assert example["input_ids"][9] == 11889  # USER
+        assert example["input_ids"][0:5] == [
+            1,
+            28962,
+            1254,
+            12665,
+            29901,
+        ]  # "<s>SYSTEM:"
+        assert example["input_ids"][5:7] == [671, 20118]  # " use cot"
+        assert example["input_ids"][8] == 11889  # USER
 
 
 class Llama2ChatTokenizationTest(unittest.TestCase):