hf_text-generation-inference/server/text_generation_server/layers/rotary.py

420 lines
17 KiB
Python

import os
import torch
from torch import nn
from text_generation_server.utils.import_utils import SYSTEM
if SYSTEM == "cuda":
from flash_attn.layers.rotary import RotaryEmbedding
import rotary_emb
elif SYSTEM == "rocm":
from vllm import pos_encoding_ops
def _create_inv_freq(dim, base, device):
inv_freq = 1.0 / (
base ** (torch.arange(0, dim, 2, device=device, dtype=torch.float32) / dim)
)
return inv_freq
def _get_rope_config(config):
if os.getenv("ROPE_SCALING", None) is not None:
rope_scaling = {
"type": os.environ["ROPE_SCALING"],
"factor": float(os.environ["ROPE_FACTOR"]),
}
return rope_scaling
return getattr(config, "rope_scaling", None)
class PositionRotaryEmbedding(nn.Module):
def __init__(self, inv_freq, scaling_factor):
super().__init__()
self.inv_freq = inv_freq
self._seq_len_cached = 0
self._cos_cached = None
self._sin_cached = None
self._cos_k_cached = None
self._sin_k_cached = None
self.scaling_factor = scaling_factor
self.dynamic_args = None
def forward(
self,
query: torch.Tensor,
key: torch.Tensor,
cos: torch.Tensor,
sin: torch.Tensor,
):
# Such controlflows may add some overhead.
if SYSTEM == "cuda":
rotary_dim = cos.shape[-1]
q1 = query[..., :rotary_dim]
q2 = query[..., rotary_dim : 2 * rotary_dim]
rotary_emb.apply_rotary(q1, q2, cos, sin, q1, q2, False)
k1 = key[..., :rotary_dim]
k2 = key[..., rotary_dim : 2 * rotary_dim]
rotary_emb.apply_rotary(k1, k2, cos, sin, k1, k2, False)
elif SYSTEM == "rocm":
# NOTE: On RoCm systems, we use a ROPE implementatation adapted from VLLM which launches a single kernel for both query/key, contrary to flash-attn implementation used on NVIDIA systems.
# Compiling flash-attn rotary on RoCm, it appears hipcc is unable to unroll loops, resulting in an even slower inference compared to eager: https://github.com/pytorch/pytorch/issues/113773
head_size = query.shape[-1]
# Inplace operation, updating query and key.
pos_encoding_ops.rotary_embedding(query, key, head_size, cos, sin, True)
elif SYSTEM == "xpu":
ipex.llm.functional.rotary_embedding(
query, key, sin, cos, query.size(-1), True
)
else:
raise ValueError(
"Your system seem to be not supported. Please check your install or open an issue at https://github.com/huggingface/text-generation-inference/issues with a clear reproduction."
)
@classmethod
def static(cls, config, dim, base, device):
inv_freq = _create_inv_freq(dim, base, device)
scaling_factor = None
rope_scaling = _get_rope_config(config)
if rope_scaling is not None:
if rope_scaling["type"] == "linear":
pass
elif rope_scaling["type"] == "dynamic":
scaling_factor = rope_scaling["factor"]
return DynamicPositionRotaryEmbedding(
dim=dim,
max_position_embeddings=config.max_position_embeddings,
base=base,
device=inv_freq.device,
scaling_factor=scaling_factor,
)
elif rope_scaling["type"] == "yarn":
scaling_factor = rope_scaling["factor"]
return YarnPositionRotaryEmbedding(
dim=2 * inv_freq.shape[0],
max_position_embeddings=rope_scaling[
"original_max_position_embeddings"
],
base=10000.0,
device=inv_freq.device,
scaling_factor=scaling_factor,
extrapolation_factor=1,
attn_factor=1,
beta_fast=32,
beta_slow=1,
)
elif rope_scaling["type"] == "su":
short_factor = torch.tensor(
rope_scaling["short_factor"], dtype=torch.float32, device=device
)
short_inv_freq = 1.0 / (
short_factor
* base
** (
torch.arange(0, dim, 2, device=device, dtype=torch.float32)
/ dim
)
)
long_factor = torch.tensor(
rope_scaling["long_factor"], dtype=torch.float32, device=device
)
long_inv_freq = 1.0 / (
long_factor
* base
** (
torch.arange(0, dim, 2, device=device, dtype=torch.float32)
/ dim
)
)
original_max_position_embeddings = (
config.original_max_position_embeddings
)
max_position_embeddings = config.max_position_embeddings
if max_position_embeddings <= original_max_position_embeddings:
scaling_factor = 1.0
else:
scale = max_position_embeddings / original_max_position_embeddings
scaling_factor = math.sqrt(
1 + math.log(scale) / math.log(original_max_position_embeddings)
)
return SuRotaryEmbedding(
short_inv_freq=short_inv_freq,
long_inv_freq=long_inv_freq,
scaling_factor=scaling_factor,
original_max_position_embeddings=original_max_position_embeddings,
)
else:
raise NotImplementedError(
f"rope scaling type {rope_scaling['type']} is not implemented or invalid"
)
return cls(inv_freq, scaling_factor)
@classmethod
def load(cls, config, prefix, weights):
# XXX: Always load this in float32 !
dtype = weights.dtype
weights.dtype = torch.float32
inv_freq = weights.get_tensor(f"{prefix}.inv_freq")
weights.dtype = dtype
scaling_factor = None
rope_scaling = _get_rope_config(config)
if rope_scaling is not None:
scaling_factor = rope_scaling["factor"]
if rope_scaling["type"] == "linear":
pass
elif rope_scaling["type"] == "dynamic":
return DynamicPositionRotaryEmbedding(
dim=2 * inv_freq.shape[0],
max_position_embeddings=config.max_position_embeddings,
base=10000.0,
device=inv_freq.device,
scaling_factor=scaling_factor,
)
elif rope_scaling["type"] == "yarn":
return YarnPositionRotaryEmbedding(
dim=2 * inv_freq.shape[0],
max_position_embeddings=rope_scaling[
"original_max_position_embeddings"
],
base=10000.0,
device=inv_freq.device,
scaling_factor=scaling_factor,
extrapolation_factor=1,
attn_factor=1,
beta_fast=32,
beta_slow=1,
)
else:
raise NotImplementedError(
f"rope scaling type {rope_scaling['type']} is not implemented or invalid"
)
return cls(inv_freq, scaling_factor)
def _update_cos_sin_cache(self, dtype, device, seqlen):
# Reset the tables if the sequence length has changed,
# or if we're on a new device (possibly due to tracing for instance)
if (
seqlen > self._seq_len_cached
or self._cos_cached.device != device
or self._cos_cached.dtype != dtype
):
self._seq_len_cached = seqlen
t = torch.arange(seqlen, device=device, dtype=self.inv_freq.dtype)
if self.scaling_factor is not None:
t /= self.scaling_factor
# Don't do einsum, it converts fp32 to fp16
# freqs = torch.einsum("i,j->ij", t, self.inv_freq)
freqs = torch.outer(t, self.inv_freq.to(device=t.device))
self._cos_cached = torch.cos(freqs).to(dtype)
self._sin_cached = torch.sin(freqs).to(dtype)
def get_cos_sin(self, position_ids: torch.Tensor, max_s: int, dtype: torch.dtype):
"""
Return cos and sin for the asked position ids
"""
if SYSTEM == "rocm":
# For RoCm, we always use float cos/sin to avoid a cast.
# For NVIDIA, for some reason, the flash-attn rotary kernel requires cos/sin and query/key to be of same dtype: https://github.com/Dao-AILab/flash-attention/blob/017716451d446e464dde9aca3a3c1ed2209caaa9/csrc/rotary/rotary.cpp#L26
# But later on goes and cast cos/sin to float anyway: https://github.com/Dao-AILab/flash-attention/blob/017716451d446e464dde9aca3a3c1ed2209caaa9/csrc/rotary/rotary_cuda.cu#L29, which looks suboptimal.
dtype = torch.float32
self._update_cos_sin_cache(dtype, position_ids.device, max_s)
cos = torch.index_select(self._cos_cached, 0, position_ids)
sin = torch.index_select(self._sin_cached, 0, position_ids)
# Note: this unsqueeze is not necessary on RoCm + VLLM ROPE implementation, but we leave it as is to avoid yet an other controlflow.
return cos.unsqueeze(1), sin.unsqueeze(1)
class SuRotaryEmbedding(PositionRotaryEmbedding):
def __init__(
self,
short_inv_freq,
long_inv_freq,
scaling_factor,
original_max_position_embeddings,
):
super(PositionRotaryEmbedding, self).__init__()
self.short_inv_freq = short_inv_freq
self.long_inv_freq = long_inv_freq
self.scaling_factor = scaling_factor
self.original_max_position_embeddings = original_max_position_embeddings
self._seq_len_cached = 0
self._cos_cached = None
self._sin_cached = None
self._cos_k_cached = None
self._sin_k_cached = None
self.dynamic_args = None
def _update_cos_sin_cache(self, dtype, device, seqlen):
# Reset the tables if the sequence length has changed,
# or if we're on a new device (possibly due to tracing for instance)
if (
seqlen > self._seq_len_cached
or self._cos_cached.device != device
or self._cos_cached.dtype != dtype
):
self._seq_len_cached = seqlen
if seqlen > self.original_max_position_embeddings:
inv_freq = self.long_inv_freq
else:
inv_freq = self.short_inv_freq
t = torch.arange(seqlen, device=device, dtype=inv_freq.dtype)
if self.scaling_factor is not None:
t /= self.scaling_factor
# Don't do einsum, it converts fp32 to fp16
# freqs = torch.einsum("i,j->ij", t, self.inv_freq)
freqs = torch.outer(t, inv_freq.to(device=t.device))
self._cos_cached = torch.cos(freqs).to(dtype)
self._sin_cached = torch.sin(freqs).to(dtype)
class DynamicPositionRotaryEmbedding(PositionRotaryEmbedding):
def __init__(self, dim, max_position_embeddings, base, device, scaling_factor):
inv_freq = _create_inv_freq(dim, base, device)
super().__init__(inv_freq, scaling_factor)
self.dim = dim
self.max_position_embeddings = max_position_embeddings
self.base = base
def _update_cos_sin_cache(self, dtype, device, seqlen):
# Reset the tables if the sequence length has changed,
# or if we're on a new device (possibly due to tracing for instance)
if (
seqlen > self._seq_len_cached
or self._cos_cached.device != device
or self._cos_cached.dtype != dtype
):
if seqlen > self.max_position_embeddings:
newbase = self.base * (
(self.scaling_factor * seqlen / self.max_position_embeddings)
- (self.scaling_factor - 1)
) ** (self.dim / (self.dim - 2))
self.inv_freq = _create_inv_freq(
self.dim, newbase, self.inv_freq.device
)
self._seq_len_cached = seqlen
t = torch.arange(seqlen, device=device, dtype=self.inv_freq.dtype)
# Don't do einsum, it converts fp32 to fp16
# freqs = torch.einsum("i,j->ij", t, self.inv_freq)
freqs = torch.outer(t, self.inv_freq.to(device=t.device))
self._cos_cached = torch.cos(freqs).to(dtype)
self._sin_cached = torch.sin(freqs).to(dtype)
# Inverse dim formula to find dim based on number of rotations
import math
def find_correction_dim(num_rotations, dim, base=10000, max_position_embeddings=2048):
return (dim * math.log(max_position_embeddings / (num_rotations * 2 * math.pi))) / (
2 * math.log(base)
)
# Find dim range bounds based on rotations
def find_correction_range(
low_rot, high_rot, dim, base=10000, max_position_embeddings=2048
):
low = math.floor(find_correction_dim(low_rot, dim, base, max_position_embeddings))
high = math.ceil(find_correction_dim(high_rot, dim, base, max_position_embeddings))
return max(low, 0), min(high, dim - 1) # Clamp values just in case
def linear_ramp_mask(min, max, dim):
if min == max:
max += 0.001 # Prevent singularity
linear_func = (torch.arange(dim, dtype=torch.float32) - min) / (max - min)
ramp_func = torch.clamp(linear_func, 0, 1)
return ramp_func
def get_mscale(scale=1):
if scale <= 1:
return 1.0
return 0.1 * math.log(scale) + 1.0
class YarnPositionRotaryEmbedding(PositionRotaryEmbedding):
def __init__(
self,
dim,
max_position_embeddings,
base,
device,
scaling_factor,
*,
extrapolation_factor,
attn_factor,
beta_fast,
beta_slow,
):
inv_freq = _create_inv_freq(dim, base, device)
super().__init__(inv_freq, scaling_factor)
self.dim = dim
self.max_position_embeddings = max_position_embeddings
self.base = base
self.extrapolation_factor = extrapolation_factor
self.attn_factor = attn_factor
self.beta_fast = beta_fast
self.beta_slow = beta_slow
self.mscale = float(
get_mscale(self.scaling_factor) * self.attn_factor
) # Get n-d magnitude scaling corrected for interpolation
def _update_cos_sin_cache(self, dtype, device, seqlen):
# Reset the tables if the sequence length has changed,
# or if we're on a new device (possibly due to tracing for instance)
if (
seqlen > self._seq_len_cached
or self._cos_cached.device != device
or self._cos_cached.dtype != dtype
):
if seqlen > self.max_position_embeddings:
inv_freq_extrapolation = _create_inv_freq(
self.dim, self.base, self.inv_freq.device
)
freqs = 1.0 / inv_freq_extrapolation
inv_freq_interpolation = 1.0 / (self.scaling_factor * freqs)
low, high = find_correction_range(
self.beta_fast,
self.beta_slow,
self.dim,
self.base,
self.max_position_embeddings,
)
inv_freq_mask = (
1 - linear_ramp_mask(low, high, self.dim // 2).float().to(device)
) * self.extrapolation_factor # Get n-d rotational scaling corrected for extrapolation
inv_freq = (
inv_freq_interpolation * (1 - inv_freq_mask)
+ inv_freq_extrapolation * inv_freq_mask
)
self.inv_freq = inv_freq
self.mscale = float(
get_mscale(self.scaling_factor) * self.attn_factor
) # Get n-d magnitude scaling corrected for interpolation
self._seq_len_cached = seqlen
t = torch.arange(seqlen, device=device, dtype=self.inv_freq.dtype)
# Don't do einsum, it converts fp32 to fp16
# freqs = torch.einsum("i,j->ij", t, self.inv_freq)
freqs = torch.outer(t, self.inv_freq.to(device=t.device))
self._cos_cached = (torch.cos(freqs) * self.mscale).to(dtype)
self._sin_cached = (torch.sin(freqs) * self.mscale).to(dtype)