mirror of https://github.com/InternLM/InternLM
fix(model): fix errant inference_forward (#396)
* Fix errant inference_forward. * Recover use_dynamic_ntk_rope. * Fix bugs. * Fit to flash attention 1.0 * Fit to flash attention 1.0 * Fit to flash attention 1.0.5. * Fit to flash attention 1.0.5.pull/408/head
parent
a075153adf
commit
b3645b0244
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@ -1,11 +1,29 @@
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#!/usr/bin/env python
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# -*- encoding: utf-8 -*-
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import math
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import warnings
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from typing import Optional
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import torch
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import torch.nn.functional as F
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from einops import rearrange
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try:
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from flash_attn.flash_attn_interface import flash_attn_unpadded_func
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except ImportError:
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try:
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from flash_attn.flash_attn_interface import (
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flash_attn_unpadded_kvpacked_func as flash_attn_unpadded_func,
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)
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except ImportError:
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try:
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from flash_attn.flash_attn_interface import (
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flash_attn_varlen_kvpacked_func as flash_attn_unpadded_func,
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)
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except ImportError:
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raise ImportError("Please check your flash_attn version >= 1.0.5.")
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from flash_attn.modules.mha import (
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CrossAttention,
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FlashCrossAttention,
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@ -127,7 +145,7 @@ class MHA(nn.Module):
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else:
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return self._forward(x=x, seqlen=seqlen, inference_params=inference_params, **kwargs)
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def _forward(self, x, seqlen=None, inference_params=None, **kwargs):
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def _forward(self, x, seqlen=None, inference_params=None, **kwargs): # pylint: disable=W0613
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"""
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Arguments:
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x: (batch, seqlen, hidden_dim) (where hidden_dim = num heads * head dim) if seqlen=None.
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@ -135,6 +153,7 @@ class MHA(nn.Module):
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split x during sequence parallel, we split the batch * seqlen dimension
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(in case batch is small).
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"""
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bsz, _, _ = x.shape
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qkv = self.Wqkv(x)
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if seqlen is None:
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qkv = rearrange(qkv, "b s (three h d) -> b s three h d", three=3, d=self.head_dim)
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@ -142,9 +161,8 @@ class MHA(nn.Module):
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qkv = rearrange(qkv, "(b s) (three h d) -> b s three h d", s=seqlen, three=3, d=self.head_dim)
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if inference_params is None:
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if self.rotary_emb_dim > 0:
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kwargs["inference_params"] = inference_params
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qkv = self.rotary_emb(qkv, **kwargs)
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kwargs["inference_params"] = inference_params
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qkv = self.rotary_emb(qkv, **kwargs)
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if gpc.config.model.dtype is torch.float32 and gpc.config.model.use_flash_attn:
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with torch.cuda.amp.autocast(dtype=torch.bfloat16):
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if qkv.dtype not in [torch.float16, torch.bfloat16]:
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@ -152,6 +170,7 @@ class MHA(nn.Module):
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context = self.inner_attn(qkv).to(x.dtype)
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else:
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context = self.inner_attn(qkv)
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else:
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if self.use_dynamic_ntk_rope:
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q = qkv[:, :, 0]
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@ -179,17 +198,131 @@ class MHA(nn.Module):
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q = qkv[:, :, 0]
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kv = qkv[:, :, 1:]
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else:
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if self.rotary_emb_dim > 0:
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kwargs["inference_params"] = inference_params
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qkv = self.rotary_emb(qkv, **kwargs)
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q = qkv[:, :, 0]
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assert self.layer_idx is not None, "Generation requires layer_idx in the constructor"
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kv = _update_kv_cache(qkv[:, :, 1:], inference_params, self.layer_idx)
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q, k, v = (x.squeeze(2) for x in qkv.chunk(chunks=3, dim=2))
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kv = torch.stack([k, v], dim=2)
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assert self.rotary_emb_dim > 0, "You should use rotary_emb."
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# If we're processing the prompt, causal=None (use self.causal).
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# If we're decoding, then causal=False.
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causal = None if inference_params.sequence_len_offset == 0 else False
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context = self.inner_cross_attn(q, kv, causal=causal)
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if hasattr(inference_params, "attention_mask") and inference_params.attention_mask is not None:
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empties = inference_params.attention_mask[..., -1].sum(dim=-1)
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if inference_params.sequence_len_offset == 0:
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moved_q = q.clone()
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moved_k = k.clone()
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for i in range(len(empties)):
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if empties[i] != 0:
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moved_q[i][: -empties[i]] = q[i][empties[i] :]
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moved_k[i][: -empties[i]] = k[i][empties[i] :]
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moved_q = self.rotary_emb._single_eval_forward(moved_q, seqlen_offset=0)
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moved_k = self.rotary_emb._single_eval_forward(moved_k, seqlen_offset=0)
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for i in range(len(empties)):
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if empties[i] != 0:
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q[i][empties[i] :] = moved_q[i][: -empties[i]]
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k[i][empties[i] :] = moved_k[i][: -empties[i]]
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else:
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q[i] = moved_q[i]
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k[i] = moved_k[i]
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elif not self.use_dynamic_ntk_rope:
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if inference_params.sequence_len_offset > self.max_position_embeddings:
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warnings.warn(
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"Notice your prompt's length is longer than model's max_position_embeddings: "
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f"{self.max_position_embeddings}, may cause deviations in dynamic ntk calculations."
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)
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q = q.squeeze(1)
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k = k.squeeze(1)
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q = self.rotary_emb._single_forward(
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q,
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inference_params.sequence_len_offset
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* torch.ones(q.size(0), dtype=torch.int, device=q.device)
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- empties,
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).unsqueeze(1)
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k = self.rotary_emb._single_forward(
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k,
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inference_params.sequence_len_offset
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* torch.ones(k.size(0), dtype=torch.int, device=k.device)
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- empties,
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).unsqueeze(1)
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else:
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q = q.squeeze(1)
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q = self.rotary_emb._single_forward(
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q,
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inference_params.sequence_len_offset
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* torch.ones(q.size(0), dtype=torch.int, device=q.device)
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- empties,
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).unsqueeze(1)
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moved_k = k.clone()
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for i in range(len(empties)):
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if empties[i] != 0:
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moved_k[i][: -empties[i]] = k[i][empties[i] :]
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moved_k = self.rotary_emb._single_eval_forward(moved_k, seqlen_offset=0)
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for i in range(len(empties)):
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if empties[i] != 0:
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k[i][empties[i] :] = moved_k[i][: -empties[i]]
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else:
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k[i] = moved_k[i]
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else:
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q = self.rotary_emb._single_forward(q, inference_params.sequence_len_offset)
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k = self.rotary_emb._single_forward(k, inference_params.sequence_len_offset)
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kv = torch.stack([k, v], dim=2)
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kv = _update_kv_cache(kv, inference_params, self.layer_idx)
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if hasattr(inference_params, "attention_mask") and inference_params.attention_mask is not None:
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if inference_params.sequence_len_offset == 0: # First entrance, attnmask (bs*seqlen*seqlen)
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attn_mask = inference_params.attention_mask[:, None, ...]
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attn_mask = torch.logical_or(
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torch.ones_like(attn_mask, dtype=torch.bool).triu(diagonal=1), attn_mask
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)
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attn_mask4flsh = ~attn_mask[:, :, -1, :].view(bsz, -1)
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cu_seqlens = torch.concat(
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[
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torch.tensor([0], dtype=torch.int32, device=attn_mask4flsh.device),
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attn_mask4flsh.sum(dim=-1).to(dtype=torch.int32),
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],
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dim=0,
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)
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cu_seqlens = cu_seqlens.cumsum(dim=0, dtype=torch.int32)
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max_seqlen_q = attn_mask4flsh.shape[-1]
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max_seqlen_k = attn_mask4flsh.shape[-1]
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total_q = q.masked_select(attn_mask4flsh.view(bsz, -1, 1, 1)).view(-1, q.shape[-2], q.shape[-1])
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total_kv = kv.masked_select(attn_mask4flsh.view(bsz, -1, 1, 1, 1)).view(
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-1, kv.shape[-3], kv.shape[-2], kv.shape[-1]
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)
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if gpc.config.model.dtype is torch.float32 and gpc.config.model.use_flash_attn:
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with torch.cuda.amp.autocast(dtype=torch.bfloat16):
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if total_q.dtype not in [torch.float16, torch.bfloat16]:
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total_q = total_q.to(torch.bfloat16)
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if total_kv.dtype not in [torch.float16, torch.bfloat16]:
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total_kv = total_kv.to(torch.bfloat16)
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output = flash_attn_unpadded_func(
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total_q, total_kv, cu_seqlens, cu_seqlens, max_seqlen_q, max_seqlen_k, 0.0, None, True, False
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).to(x.dtype)
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context = torch.zeros_like(q)
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context = context.masked_scatter_(attn_mask4flsh.view(bsz, -1, 1, 1), output)
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else:
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attn_mask = inference_params.attention_mask[:, -1, :].view(bsz, 1, 1, -1)
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k, v = torch.chunk(kv, 2, dim=2)
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k = k.squeeze(2)
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v = v.squeeze(2)
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sp = k.shape
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scores = torch.einsum(
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"blhd,bnhd->bhln",
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q,
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k.reshape(sp[0], sp[1], q.size(2), sp[3]),
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) / math.sqrt(q.size(-1))
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scores = scores.masked_fill(attn_mask, -65000.0)
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scores = F.softmax(scores, dim=-1) # bsz x h x L x L
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context = torch.einsum(
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"bhmn,bnhd->bmhd",
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scores,
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v.reshape(sp[0], sp[1], q.size(2), sp[3]),
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)
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else:
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context = self.inner_cross_attn(q, kv, causal=True)
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if seqlen is None:
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context = rearrange(context, "b s h d -> b s (h d)")
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