support flash attn 2

config.json

@@ -21,8 +21,9 @@
   "num_key_value_heads": 8,
   "pad_token_id": 2,
   "rms_norm_eps": 1e-05,
-  "rotary": {
-    "base": 1000000,
+  "rope_theta": 1000000,
+  "rope_scaling": {
+    "factor": 1.0,
     "type": "dynamic"
   },
   "tie_word_embeddings": false,

configuration_internlm.py

@@ -106,7 +106,9 @@ class InternLMConfig(PretrainedConfig):
         eos_token_id=2,
         tie_word_embeddings=False,
         bias=True,
-        rotary={"base": 10000, "type": "dynamic"},  # pylint: disable=W0102
+        rope_theta=10000,
+        rope_scaling=None,
+        attn_implementation="eager",
         **kwargs,
     ):
         self.vocab_size = vocab_size
@@ -115,6 +117,7 @@ class InternLMConfig(PretrainedConfig):
         self.intermediate_size = intermediate_size
         self.num_hidden_layers = num_hidden_layers
         self.num_attention_heads = num_attention_heads
+        self.bias = bias
 
         if num_key_value_heads is None:
             num_key_value_heads = num_attention_heads
@@ -124,8 +127,13 @@ class InternLMConfig(PretrainedConfig):
         self.initializer_range = initializer_range
         self.rms_norm_eps = rms_norm_eps
         self.use_cache = use_cache
-        self.bias = bias
-        self.rotary = rotary
+        self.rope_theta = rope_theta
+        self.rope_scaling = rope_scaling
+        self._rope_scaling_validation()
+
+        self.attn_implementation = attn_implementation
+        if self.attn_implementation is None:
+            self.attn_implementation = "eager"
         super().__init__(
             pad_token_id=pad_token_id,
             bos_token_id=bos_token_id,
@@ -133,3 +141,24 @@ class InternLMConfig(PretrainedConfig):
             tie_word_embeddings=tie_word_embeddings,
             **kwargs,
         )
+
+    def _rope_scaling_validation(self):
+        """
+        Validate the `rope_scaling` configuration.
+        """
+        if self.rope_scaling is None:
+            return
+
+        if not isinstance(self.rope_scaling, dict) or len(self.rope_scaling) != 2:
+            raise ValueError(
+                "`rope_scaling` must be a dictionary with with two fields, `type` and `factor`, "
+                f"got {self.rope_scaling}"
+            )
+        rope_scaling_type = self.rope_scaling.get("type", None)
+        rope_scaling_factor = self.rope_scaling.get("factor", None)
+        if rope_scaling_type is None or rope_scaling_type not in ["linear", "dynamic"]:
+            raise ValueError(
+                f"`rope_scaling`'s type field must be one of ['linear', 'dynamic'], got {rope_scaling_type}"
+            )
+        if rope_scaling_factor is None or not isinstance(rope_scaling_factor, float) or rope_scaling_factor < 1.0:
+            raise ValueError(f"`rope_scaling`'s factor field must be a float >= 1, got {rope_scaling_factor}")

modeling_internlm2.py

@@ -1,10 +1,6 @@
-# coding=utf-8
-# # Copyright (c) InternLM. All rights reserved.
+# Copyright (c) The InternLM team and The HuggingFace Inc. team. All rights reserved.
 #
-# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
-# and OPT implementations in this library. It has been modified from its
-# original forms to accommodate minor architectural differences compared
-# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
+# This code is based on transformers/src/transformers/models/llama/modeling_llama.py
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -25,6 +21,7 @@ import warnings
 from typing import List, Optional, Tuple, Union
 
 import torch
+import torch.nn.functional as F
 import torch.utils.checkpoint
 from einops import rearrange
 from torch import nn
@@ -54,6 +51,18 @@ logger = logging.get_logger(__name__)
 
 _CONFIG_FOR_DOC = "InternLM2Config"
 
+# Copied from transformers.models.llama.modeling_llama._get_unpad_data
+def _get_unpad_data(attention_mask):
+    seqlens_in_batch = attention_mask.sum(dim=-1, dtype=torch.int32)
+    indices = torch.nonzero(attention_mask.flatten(), as_tuple=False).flatten()
+    max_seqlen_in_batch = seqlens_in_batch.max().item()
+    cu_seqlens = F.pad(torch.cumsum(seqlens_in_batch, dim=0, dtype=torch.torch.int32), (1, 0))
+    return (
+        indices,
+        cu_seqlens,
+        max_seqlen_in_batch,
+    )
+
 
 # Copied from transformers.models.bart.modeling_bart._make_causal_mask
 def _make_causal_mask(
@@ -88,6 +97,7 @@ def _expand_mask(mask: torch.Tensor, dtype: torch.dtype, tgt_len: Optional[int]
     return inverted_mask.masked_fill(inverted_mask.to(torch.bool), torch.finfo(dtype).min)
 
 
+# Copied from transformers.models.llama.modeling_llama.LlamaRMSNorm with Llama->InternLM2
 class InternLM2RMSNorm(nn.Module):
     def __init__(self, hidden_size, eps=1e-6):
         """
@@ -105,6 +115,7 @@ class InternLM2RMSNorm(nn.Module):
         return self.weight * hidden_states.to(input_dtype)
 
 
+# Copied from transformers.model.llama.modeling_llama.LlamaRotaryEmbedding with Llama->InternLM2
 class InternLM2RotaryEmbedding(nn.Module):
     def __init__(self, dim, max_position_embeddings=2048, base=10000, device=None):
         super().__init__()
@@ -133,7 +144,7 @@ class InternLM2RotaryEmbedding(nn.Module):
     def forward(self, x, seq_len=None):
         # x: [bs, num_attention_heads, seq_len, head_size]
         if seq_len > self.max_seq_len_cached:
-            self._set_cos_sin_cache(seq_len=seq_len, device=x.device, dtype=x.dtype)
+            self._set_cos_sin_cache(seq_len=seq_len, device=x.device, dtype=torch.float32)
 
         return (
             self.cos_cached[:seq_len].to(dtype=x.dtype),
@@ -141,6 +152,7 @@ class InternLM2RotaryEmbedding(nn.Module):
         )
 
 
+# Copied from transformers.model.llama.modeling_llama.LlamaLinearScalingRotaryEmbedding with Llama->InternLM2
 class InternLM2LinearScalingRotaryEmbedding(InternLM2RotaryEmbedding):
     """InternLM2RotaryEmbedding extended with linear scaling. Credits to the Reddit user /u/kaiokendev"""
 
@@ -160,6 +172,7 @@ class InternLM2LinearScalingRotaryEmbedding(InternLM2RotaryEmbedding):
         self.register_buffer("sin_cached", emb.sin().to(dtype), persistent=False)
 
 
+# Copied from transformers.model.llama.modeling_llama.LlamaDynamicNTKScalingRotaryEmbedding with Llama->InternLM2
 class InternLM2DynamicNTKScalingRotaryEmbedding(InternLM2RotaryEmbedding):
     """InternLM2RotaryEmbedding extended with Dynamic NTK scaling.
     Credits to the Reddit users /u/bloc97 and /u/emozilla.
@@ -188,6 +201,7 @@ class InternLM2DynamicNTKScalingRotaryEmbedding(InternLM2RotaryEmbedding):
         self.register_buffer("sin_cached", emb.sin().to(dtype), persistent=False)
 
 
+# Copied from transformers.model.llama.modeling_llama.rotate_half
 def rotate_half(x):
     """Rotates half the hidden dims of the input."""
     x1 = x[..., : x.shape[-1] // 2]
@@ -195,22 +209,13 @@ def rotate_half(x):
     return torch.cat((-x2, x1), dim=-1)
 
 
-def apply_rotary_pos_emb(q, k, cos, sin, position_ids):
-    # The first two dimensions of cos and sin are always 1, so we can `squeeze` them.
-    cos = cos.squeeze(1).squeeze(0)  # [seq_len, dim]
-    sin = sin.squeeze(1).squeeze(0)  # [seq_len, dim]
-    cos = cos.unsqueeze(0).unsqueeze(0).expand(len(position_ids), -1, -1, -1)
-    sin = sin.unsqueeze(0).unsqueeze(0).expand(len(position_ids), -1, -1, -1)
-    if q.size(2) == 1:
-        q_embed = (q * cos[:, :, -1, :]) + (rotate_half(q) * sin[:, :, -1, :])
-    else:
-        q_embed = (q * cos) + (rotate_half(q) * sin)
-
-    if k.size(2) == 1:
-        k_embed = (k * cos[:, :, -1, :]) + (rotate_half(k) * sin[:, :, -1, :])
-    else:
-        k_embed = (k * cos) + (rotate_half(k) * sin)
-
+# Copied from transformers.model.llama.modeling_llama.apply_rotary_pos_emb
+def apply_rotary_pos_emb(q, k, cos, sin, position_ids, unsqueeze_dim=1):
+    """Applies Rotary Position Embedding to the query and key tensors."""
+    cos = cos[position_ids].unsqueeze(unsqueeze_dim)
+    sin = sin[position_ids].unsqueeze(unsqueeze_dim)
+    q_embed = (q * cos) + (rotate_half(q) * sin)
+    k_embed = (k * cos) + (rotate_half(k) * sin)
     return q_embed, k_embed
 
 
@@ -231,6 +236,7 @@ class InternLM2MLP(nn.Module):
         return down_proj
 
 
+# Copied from transformers.model.llama.modeling_llama.repeat_kv
 def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
     """
     This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch,
@@ -243,6 +249,7 @@ def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor:
     return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim)
 
 
+# Modified from transformers.model.llama.modeling_llama.LlamaAttention
 class InternLM2Attention(nn.Module):
     """Multi-headed attention from 'Attention Is All You Need' paper"""
 
@@ -273,21 +280,31 @@ class InternLM2Attention(nn.Module):
         self._init_rope()
 
     def _init_rope(self):
-        if self.config.rotary["type"] == "origin":
+        if self.config.rope_scaling is None:
             self.rotary_emb = InternLM2RotaryEmbedding(
                 self.head_dim,
                 max_position_embeddings=self.max_position_embeddings,
-                base=self.config.rotary["base"],
-            )
-        elif self.config.rotary["type"] == "dynamic":
-            self.rotary_emb = InternLM2DynamicNTKScalingRotaryEmbedding(
-                self.head_dim,
-                max_position_embeddings=self.max_position_embeddings,
-                base=self.config.rotary["base"],
-                scaling_factor=self.config.rotary.get("scaling_factor", 1.0),
+                base=self.config.rope_theta,
             )
         else:
-            raise ValueError("Currently we only support rotary embedding's type being one of ('origin', 'dynamic').")
+            scaling_type = self.config.rope_scaling["type"]
+            scaling_factor = self.config.rope_scaling["factor"]
+            if scaling_type == "dynamic":
+                self.rotary_emb = InternLM2DynamicNTKScalingRotaryEmbedding(
+                    self.head_dim,
+                    max_position_embeddings=self.max_position_embeddings,
+                    base=self.config.rope_theta,
+                    scaling_factor=scaling_factor,
+                )
+            elif scaling_type == "linear":
+                self.rotary_emb = InternLM2LinearScalingRotaryEmbedding(
+                    self.head_dim,
+                    max_position_embeddings=self.max_position_embeddings,
+                    base=self.config.rope_theta,
+                    scaling_factor=scaling_factor,
+                )
+            else:
+                raise ValueError("Currently we only support rotary embedding's type being 'dynamic' or 'linear'.")
         return self.rotary_emb
 
     def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
@@ -381,6 +398,7 @@ class InternLM2Attention(nn.Module):
         return attn_output, attn_weights, past_key_value
 
 
+# Modified from transformers.model.llama.modeling_llama.InternLM2FlashAttention2
 class InternLM2FlashAttention2(InternLM2Attention):
     """
     InternLM2 flash attention module. This module inherits from `InternLM2Attention` as the weights of the module stays
@@ -417,9 +435,8 @@ class InternLM2FlashAttention2(InternLM2Attention):
         qkv_states = rearrange(
             qkv_states,
             "b q (h gs d) -> b q h gs d",
-            gs=self.num_heads + 2 * self.num_key_value_heads,
+            gs=2 + self.num_key_value_groups,
             d=self.head_dim,
-            q=q_len,
         )
 
         query_states = qkv_states[..., : self.num_key_value_groups, :]
@@ -427,6 +444,10 @@ class InternLM2FlashAttention2(InternLM2Attention):
         key_states = qkv_states[..., -2, :]
         value_states = qkv_states[..., -1, :]
 
+        query_states = query_states.transpose(1, 2)
+        key_states = key_states.transpose(1, 2)
+        value_states = value_states.transpose(1, 2)
+
         kv_seq_len = key_states.shape[-2]
         if past_key_value is not None:
             kv_seq_len += past_key_value[0].shape[-2]
@@ -448,34 +469,9 @@ class InternLM2FlashAttention2(InternLM2Attention):
 
         dropout_rate = 0.0 if not self.training else self.attention_dropout
 
-        # In PEFT, usually we cast the layer norms in float32 for training stability reasons
-        # therefore the input hidden states gets silently casted in float32. Hence, we need
-        # cast them back in the correct dtype just to be sure everything works as expected.
-        # This might slowdown training & inference so it is recommended to not cast the LayerNorms
-        # in fp32. (InternLM2RMSNorm handles it correctly)
-
-        input_dtype = query_states.dtype
-        if input_dtype == torch.float32:
-            # Handle the case where the model is quantized
-            if hasattr(self.config, "_pre_quantization_dtype"):
-                target_dtype = self.config._pre_quantization_dtype
-            else:
-                target_dtype = self.q_proj.weight.dtype
-
-            logger.warning_once(
-                f"The input hidden states seems to be silently casted in float32, this might be related to"
-                f" the fact you have upcasted embedding or layer norm layers in float32. We will cast back "
-                f"the input in {target_dtype}."
-            )
-
-            query_states = query_states.to(target_dtype)
-            key_states = key_states.to(target_dtype)
-            value_states = value_states.to(target_dtype)
-
         attn_output = self._flash_attention_forward(
             query_states, key_states, value_states, attention_mask, q_len, dropout=dropout_rate
         )
-
         attn_output = attn_output.reshape(bsz, q_len, self.hidden_size).contiguous()
         attn_output = self.wo(attn_output)
 
@@ -484,16 +480,115 @@ class InternLM2FlashAttention2(InternLM2Attention):
 
         return attn_output, attn_weights, past_key_value
 
+    def _flash_attention_forward(
+        self, query_states, key_states, value_states, attention_mask, query_length, dropout=0.0, softmax_scale=None
+    ):
+        """
+        Calls the forward method of Flash Attention - if the input hidden states contain at least one padding token
+        first unpad the input, then computes the attention scores and pad the final attention scores.
+
+        Args:
+            query_states (`torch.Tensor`):
+                Input query states to be passed to Flash Attention API
+            key_states (`torch.Tensor`):
+                Input key states to be passed to Flash Attention API
+            value_states (`torch.Tensor`):
+                Input value states to be passed to Flash Attention API
+            attention_mask (`torch.Tensor`):
+                The padding mask - corresponds to a tensor of size `(batch_size, seq_len)` where 0 stands for the
+                position of padding tokens and 1 for the position of non-padding tokens.
+            dropout (`int`, *optional*):
+                Attention dropout
+            softmax_scale (`float`, *optional*):
+                The scaling of QK^T before applying softmax. Default to 1 / sqrt(head_dim)
+        """
+        from flash_attn import flash_attn_func, flash_attn_varlen_func
+        from flash_attn.bert_padding import pad_input
+        # Contains at least one padding token in the sequence
+        causal = self.is_causal and query_length != 1
+        if attention_mask is not None:
+            batch_size = query_states.shape[0]
+            query_states, key_states, value_states, indices_q, cu_seq_lens, max_seq_lens = self._upad_input(
+                query_states, key_states, value_states, attention_mask, query_length
+            )
+
+            cu_seqlens_q, cu_seqlens_k = cu_seq_lens
+            max_seqlen_in_batch_q, max_seqlen_in_batch_k = max_seq_lens
+
+            attn_output_unpad = flash_attn_varlen_func(
+                query_states,
+                key_states,
+                value_states,
+                cu_seqlens_q=cu_seqlens_q,
+                cu_seqlens_k=cu_seqlens_k,
+                max_seqlen_q=max_seqlen_in_batch_q,
+                max_seqlen_k=max_seqlen_in_batch_k,
+                dropout_p=dropout,
+                softmax_scale=softmax_scale,
+                causal=causal,
+            )
+
+            attn_output = pad_input(attn_output_unpad, indices_q, batch_size, query_length)
+        else:
+            attn_output = flash_attn_func(
+                query_states, key_states, value_states, dropout, softmax_scale=softmax_scale, causal=causal
+            )
+
+        return attn_output
+
+    def _upad_input(self, query_layer, key_layer, value_layer, attention_mask, query_length):
+        from flash_attn.bert_padding import index_first_axis, unpad_input
+        indices_k, cu_seqlens_k, max_seqlen_in_batch_k = _get_unpad_data(attention_mask)
+        batch_size, kv_seq_len, num_key_value_heads, head_dim = key_layer.shape
+
+        key_layer = index_first_axis(
+            key_layer.reshape(batch_size * kv_seq_len, num_key_value_heads, head_dim), indices_k
+        )
+        value_layer = index_first_axis(
+            value_layer.reshape(batch_size * kv_seq_len, num_key_value_heads, head_dim), indices_k
+        )
+
+        if query_length == kv_seq_len:
+            query_layer = index_first_axis(
+                query_layer.reshape(batch_size * kv_seq_len, self.num_heads, head_dim), indices_k
+            )
+            cu_seqlens_q = cu_seqlens_k
+            max_seqlen_in_batch_q = max_seqlen_in_batch_k
+            indices_q = indices_k
+        elif query_length == 1:
+            max_seqlen_in_batch_q = 1
+            cu_seqlens_q = torch.arange(
+                batch_size + 1, dtype=torch.int32, device=query_layer.device
+            )  # There is a memcpy here, that is very bad.
+            indices_q = cu_seqlens_q[:-1]
+            query_layer = query_layer.squeeze(1)
+        else:
+            # The -q_len: slice assumes left padding.
+            attention_mask = attention_mask[:, -query_length:]
+            query_layer, indices_q, cu_seqlens_q, max_seqlen_in_batch_q = unpad_input(query_layer, attention_mask)
+
+        return (
+            query_layer,
+            key_layer,
+            value_layer,
+            indices_q.to(torch.int64),
+            (cu_seqlens_q, cu_seqlens_k),
+            (max_seqlen_in_batch_q, max_seqlen_in_batch_k),
+        )
+
+INTERNLM2_ATTENTION_CLASSES = {
+    "eager": InternLM2Attention,
+    "flash_attention_2": InternLM2FlashAttention2,
+}
 
+# Modified from transformers.model.llama.modeling_llama.LlamaDecoderLayer
 class InternLM2DecoderLayer(nn.Module):
     def __init__(self, config: InternLM2Config):
         super().__init__()
         self.hidden_size = config.hidden_size
-        self.attention = (
-            InternLM2Attention(config=config)
-            if not getattr(config, "_flash_attn_2_enabled", False)
-            else InternLM2FlashAttention2(config=config)
-        )
+
+        self.attention = INTERNLM2_ATTENTION_CLASSES[config.attn_implementation](config=config)
+
         self.feed_forward = InternLM2MLP(config)
         self.attention_norm = InternLM2RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
         self.ffn_norm = InternLM2RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
@@ -565,9 +660,11 @@ InternLM2_START_DOCSTRING = r"""
     This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the
     library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
     etc.)
+
     This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
     Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
     and behavior.
+
     Parameters:
         config ([`InternLM2Config`]):
             Model configuration class with all the parameters of the model. Initializing with a config file does not
@@ -576,6 +673,7 @@ InternLM2_START_DOCSTRING = r"""
 """
 
 
+# Copied from transformers.models.llama.modeling_llama.LlamaPreTrainedModel with Llama->InternLM2
 @add_start_docstrings(
     "The bare InternLM2 Model outputting raw hidden-states without any specific head on top.",
     InternLM2_START_DOCSTRING,
@@ -586,7 +684,6 @@ class InternLM2PreTrainedModel(PreTrainedModel):
     supports_gradient_checkpointing = True
     _no_split_modules = ["InternLM2DecoderLayer"]
     _skip_keys_device_placement = "past_key_values"
-    _supports_flash_attn_2 = True
 
     def _init_weights(self, module):
         std = self.config.initializer_range
@@ -605,34 +702,45 @@ InternLM2_INPUTS_DOCSTRING = r"""
         input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
             Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you provide
             it.
+
             Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
             [`PreTrainedTokenizer.__call__`] for details.
+
             [What are input IDs?](../glossary#input-ids)
         attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
             Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`:
+
             - 1 for tokens that are **not masked**,
             - 0 for tokens that are **masked**.
+
             [What are attention masks?](../glossary#attention-mask)
+
             Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
             [`PreTrainedTokenizer.__call__`] for details.
+
             If `past_key_values` is used, optionally only the last `input_ids` have to be input (see
             `past_key_values`).
+
             If you want to change padding behavior, you should read [`modeling_opt._prepare_decoder_attention_mask`]
             and modify to your needs. See diagram 1 in [the paper](https://arxiv.org/abs/1910.13461) for more
             information on the default strategy.
+
             - 1 indicates the head is **not masked**,
             - 0 indicates the head is **masked**.
         position_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
             Indices of positions of each input sequence tokens in the position embeddings. Selected in the range `[0,
             config.n_positions - 1]`.
+
             [What are position IDs?](../glossary#position-ids)
         past_key_values (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `use_cache=True` is passed or
             when `config.use_cache=True`):
             Tuple of `tuple(torch.FloatTensor)` of length `config.n_layers`, with each tuple having 2 tensors of shape
             `(batch_size, num_heads, sequence_length, embed_size_per_head)`) and 2 additional tensors of shape
             `(batch_size, num_heads, decoder_sequence_length, embed_size_per_head)`.
+
             Contains pre-computed hidden-states (key and values in the self-attention blocks and in the cross-attention
             blocks) that can be used (see `past_key_values` input) to speed up sequential decoding.
+
             If `past_key_values` are used, the user can optionally input only the last `input_ids` (those that don't
             have their past key value states given to this model) of shape `(batch_size, 1)` instead of all `input_ids`
             of shape `(batch_size, sequence_length)`.
@@ -654,6 +762,7 @@ InternLM2_INPUTS_DOCSTRING = r"""
 """
 
 
+# Modified from transformers.model.llama.modeling_llama.LlamaModel
 @add_start_docstrings(
     "The bare InternLM2 Model outputting raw hidden-states without any specific head on top.",
     InternLM2_START_DOCSTRING,
@@ -661,6 +770,7 @@ InternLM2_INPUTS_DOCSTRING = r"""
 class InternLM2Model(InternLM2PreTrainedModel):
     """
     Transformer decoder consisting of *config.num_hidden_layers* layers. Each layer is a [`InternLM2DecoderLayer`]
+
     Args:
         config: InternLM2Config
     """
@@ -671,8 +781,10 @@ class InternLM2Model(InternLM2PreTrainedModel):
         super().__init__(config)
         self.padding_idx = config.pad_token_id
         self.vocab_size = config.vocab_size
+        self.config = config
 
         self.tok_embeddings = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
+
         self.layers = nn.ModuleList([InternLM2DecoderLayer(config) for _ in range(config.num_hidden_layers)])
         self.norm = InternLM2RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
 
@@ -686,7 +798,6 @@ class InternLM2Model(InternLM2PreTrainedModel):
     def set_input_embeddings(self, value):
         self.tok_embeddings = value
 
-    # Copied from transformers.models.bart.modeling_bart.BartDecoder._prepare_decoder_attention_mask
     def _prepare_decoder_attention_mask(self, attention_mask, input_shape, inputs_embeds, past_key_values_length):
         # create causal mask
         # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
@@ -756,14 +867,18 @@ class InternLM2Model(InternLM2PreTrainedModel):
 
         if inputs_embeds is None:
             inputs_embeds = self.tok_embeddings(input_ids)
-        # embed positions
-        if attention_mask is None:
-            attention_mask = torch.ones(
-                (batch_size, seq_length_with_past), dtype=torch.bool, device=inputs_embeds.device
+
+        if self.config.attn_implementation == "flash_attention_2":
+            # 2d mask is passed through the layers
+            attention_mask = attention_mask if (attention_mask is not None and 0 in attention_mask) else None
+        else:
+            if attention_mask is None:
+                attention_mask = torch.ones(
+                    (batch_size, seq_length_with_past), dtype=torch.bool, device=inputs_embeds.device
+                )
+            attention_mask = self._prepare_decoder_attention_mask(
+                attention_mask, (batch_size, seq_length), inputs_embeds, past_key_values_length
             )
-        attention_mask = self._prepare_decoder_attention_mask(
-            attention_mask, (batch_size, seq_length), inputs_embeds, past_key_values_length
-        )
 
         # embed positions
         hidden_states = inputs_embeds
@@ -837,6 +952,7 @@ class InternLM2Model(InternLM2PreTrainedModel):
         )
 
 
+# Modified from transformers.model.llama.modeling_llama.LlamaForCausalLM
 class InternLM2ForCausalLM(InternLM2PreTrainedModel):
     _auto_class = "AutoModelForCausalLM"
 
@@ -890,14 +1006,20 @@ class InternLM2ForCausalLM(InternLM2PreTrainedModel):
                 Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
                 config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
                 (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
+
         Returns:
+
         Example:
+
         ```python
         >>> from transformers import AutoTokenizer, InternLM2ForCausalLM
+
         >>> model = InternLM2ForCausalLM.from_pretrained(PATH_TO_CONVERTED_WEIGHTS)
         >>> tokenizer = AutoTokenizer.from_pretrained(PATH_TO_CONVERTED_TOKENIZER)
+
         >>> prompt = "Hey, are you conscious? Can you talk to me?"
         >>> inputs = tokenizer(prompt, return_tensors="pt")
+
         >>> # Generate
         >>> generate_ids = model.generate(inputs.input_ids, max_length=30)
         >>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
@@ -1000,11 +1122,15 @@ class InternLM2ForCausalLM(InternLM2PreTrainedModel):
             )
         return reordered_past
 
-    def build_inputs(self, tokenizer, query: str, history: List[Tuple[str, str]] = []):
+    def build_inputs(self, tokenizer, query: str, history: List[Tuple[str, str]] = [], meta_instruction=""):
         prompt = ""
+        if meta_instruction:
+            prompt += f"""<s>[UNUSED_TOKEN_146]system\n{meta_instruction}[UNUSED_TOKEN_145]\n"""
+        else:
+            prompt += "<s>"
         for record in history:
-            prompt += f"""<|User|>:{record[0]}<eoh>\n<|Bot|>:{record[1]}<eoa>\n"""
-        prompt += f"""<|User|>:{query}<eoh>\n<|Bot|>:"""
+            prompt += f"""[UNUSED_TOKEN_146]user\n{record[0]}[UNUSED_TOKEN_145]\n[UNUSED_TOKEN_146]assistant\n{record[1]}[UNUSED_TOKEN_145]\n"""
+        prompt += f"""[UNUSED_TOKEN_146]user\n{query}[UNUSED_TOKEN_145]\n[UNUSED_TOKEN_146]assistant\n"""
         return tokenizer([prompt], return_tensors="pt")
 
     @torch.no_grad()
@@ -1018,10 +1144,15 @@ class InternLM2ForCausalLM(InternLM2PreTrainedModel):
         do_sample: bool = True,
         temperature: float = 0.8,
         top_p: float = 0.8,
+        meta_instruction: str = "You are an AI assistant whose name is InternLM (书生·浦语).\n"
+        "- InternLM (书生·浦语) is a conversational language model that is developed by Shanghai AI Laboratory (上海人工智能实验室). It is designed to be helpful, honest, and harmless.\n"
+        "- InternLM (书生·浦语) can understand and communicate fluently in the language chosen by the user such as English and 中文.",
         **kwargs,
     ):
-        inputs = self.build_inputs(tokenizer, query, history)
+        inputs = self.build_inputs(tokenizer, query, history, meta_instruction)
         inputs = {k: v.to(self.device) for k, v in inputs.items() if torch.is_tensor(v)}
+        # also add end-of-assistant token in eos token id to avoid unnecessary generation
+        eos_token_id = [tokenizer.eos_token_id, tokenizer.convert_tokens_to_ids(["[UNUSED_TOKEN_145]"])[0]]
         outputs = self.generate(
             **inputs,
             streamer=streamer,
@@ -1029,11 +1160,12 @@ class InternLM2ForCausalLM(InternLM2PreTrainedModel):
             do_sample=do_sample,
             temperature=temperature,
             top_p=top_p,
+            eos_token_id=eos_token_id,
             **kwargs,
         )
         outputs = outputs[0].cpu().tolist()[len(inputs["input_ids"][0]) :]
         response = tokenizer.decode(outputs, skip_special_tokens=True)
-        response = response.split("<eoa>")[0]
+        response = response.split("[UNUSED_TOKEN_145]")[0]
         history = history + [(query, response)]
         return response, history
 
@@ -1086,7 +1218,7 @@ class InternLM2ForCausalLM(InternLM2PreTrainedModel):
                     return
 
                 token = self.tokenizer.decode([value[-1]], skip_special_tokens=True)
-                if token.strip() != "<eoa>":
+                if token.strip() != "[UNUSED_TOKEN_145]":
                     self.response = self.response + token
                     history = self.history + [(self.query, self.response)]
                     self.queue.put((self.response, history))
@@ -1119,11 +1251,14 @@ class InternLM2ForCausalLM(InternLM2PreTrainedModel):
         return consumer()
 
 
+# Copied from transformers.model.llama.modeling_llama.LlamaForSequenceClassification with Llama->InternLM2
 @add_start_docstrings(
     """
     The InternLM2 Model transformer with a sequence classification head on top (linear layer).
+
     [`InternLM2ForSequenceClassification`] uses the last token in order to do the classification,
     as other causal models (e.g. GPT-2) do.
+
     Since it does classification on the last token, it requires to know the position of the last token. If a
     `pad_token_id` is defined in the configuration, it finds the last token that is not a padding token in each row. If
     no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since it cannot guess the
@@ -1236,4 +1371,4 @@ class InternLM2ForSequenceClassification(InternLM2PreTrainedModel):
             past_key_values=transformer_outputs.past_key_values,
             hidden_states=transformer_outputs.hidden_states,
             attentions=transformer_outputs.attentions,
-        )
+        )