ColossalAI/colossalai/kernel/triton/token_attention_kernel.py

842 lines
27 KiB
Python

# Adapted from ModelTC https://github.com/ModelTC/lightllm
import torch
try:
import triton
import triton.language as tl
HAS_TRITON = True
except ImportError:
HAS_TRITON = False
print("please install triton from https://github.com/openai/triton")
if HAS_TRITON:
@triton.jit
def _token_attn_1_kernel(
Q,
K,
sm_scale,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seqlen,
max_kv_cache_len,
attn_out,
kv_cache_loc_b_stride,
kv_cache_loc_s_stride,
q_batch_stride,
q_head_stride,
q_head_dim_stride,
k_batch_stride,
k_head_stride,
k_head_dim_stride,
attn_head_stride,
attn_batch_stride,
HEAD_DIM: tl.constexpr,
BLOCK_N: tl.constexpr,
):
current_batch = tl.program_id(0)
current_head = tl.program_id(1)
start_n = tl.program_id(2)
offs_d = tl.arange(0, HEAD_DIM)
current_batch_seq_len = tl.load(kv_cache_seqlen + current_batch)
current_batch_in_all_start_index = tl.load(kv_cache_start_loc + current_batch)
current_batch_start_index = max_kv_cache_len - current_batch_seq_len
current_batch_end_index = max_kv_cache_len
off_q = current_batch * q_batch_stride + current_head * q_head_stride + offs_d * q_head_dim_stride
offs_n = start_n * BLOCK_N + tl.arange(0, BLOCK_N)
block_stard_index = start_n * BLOCK_N
block_mask = tl.where(block_stard_index < current_batch_seq_len, 1, 0)
for start_mark in range(0, block_mask, 1):
q = tl.load(Q + off_q + start_mark)
offs_n_new = current_batch_start_index + offs_n
k_loc = tl.load(
kv_cache_loc + kv_cache_loc_b_stride * current_batch + kv_cache_loc_s_stride * offs_n_new,
mask=offs_n_new < current_batch_end_index,
other=0,
)
off_k = k_loc[:, None] * k_batch_stride + current_head * k_head_stride + offs_d[None, :] * k_head_dim_stride
k = tl.load(K + off_k, mask=offs_n_new[:, None] < current_batch_end_index, other=0.0)
att_value = tl.sum(q[None, :] * k, 1)
att_value *= sm_scale
off_o = current_head * attn_head_stride + (current_batch_in_all_start_index + offs_n) * attn_batch_stride
tl.store(attn_out + off_o, att_value, mask=offs_n_new < current_batch_end_index)
return
@triton.jit
def _token_attn_1_alibi_kernel(
Q,
K,
sm_scale,
alibi,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seqlen,
max_kv_cache_len,
attn_out,
kv_cache_loc_b_stride,
kv_cache_loc_s_stride,
q_batch_stride,
q_head_stride,
q_head_dim_stride,
k_batch_stride,
k_head_stride,
k_head_dim_stride,
attn_head_stride,
attn_batch_stride,
HEAD_DIM: tl.constexpr,
BLOCK_N: tl.constexpr,
):
current_batch = tl.program_id(0)
current_head = tl.program_id(1)
start_n = tl.program_id(2)
offs_d = tl.arange(0, HEAD_DIM)
current_batch_seq_len = tl.load(kv_cache_seqlen + current_batch)
current_batch_in_all_start_index = tl.load(kv_cache_start_loc + current_batch)
current_batch_start_index = max_kv_cache_len - current_batch_seq_len
current_batch_end_index = max_kv_cache_len
off_q = current_batch * q_batch_stride + current_head * q_head_stride + offs_d * q_head_dim_stride
offs_n = start_n * BLOCK_N + tl.arange(0, BLOCK_N)
block_stard_index = start_n * BLOCK_N
block_mask = tl.where(block_stard_index < current_batch_seq_len, 1, 0)
for start_mark in range(0, block_mask, 1):
alibi_m = tl.load(alibi + current_head)
q = tl.load(Q + off_q + start_mark)
offs_n_new = current_batch_start_index + offs_n
k_loc = tl.load(
kv_cache_loc + kv_cache_loc_b_stride * current_batch + kv_cache_loc_s_stride * offs_n_new,
mask=offs_n_new < current_batch_end_index,
other=0,
)
off_k = k_loc[:, None] * k_batch_stride + current_head * k_head_stride + offs_d[None, :] * k_head_dim_stride
k = tl.load(K + off_k, mask=offs_n_new[:, None] < current_batch_end_index, other=0.0)
att_value = tl.sum(q[None, :] * k, 1)
att_value *= sm_scale
att_value -= alibi_m * (current_batch_seq_len - 1 - offs_n)
off_o = current_head * attn_head_stride + (current_batch_in_all_start_index + offs_n) * attn_batch_stride
tl.store(attn_out + off_o, att_value, mask=offs_n_new < current_batch_end_index)
return
@torch.no_grad()
def token_attn_fwd_1(
q, k, attn_out, kv_cache_loc, kv_cache_start_loc, kv_cache_seqlen, max_kv_cache_len, alibi=None
):
BLOCK = 32
# shape constraints
q_head_dim, k_head_dim = q.shape[-1], k.shape[-1]
assert q_head_dim == k_head_dim
assert k_head_dim in {16, 32, 64, 128}
sm_scale = 1.0 / (k_head_dim**0.5)
batch, head_num = kv_cache_loc.shape[0], q.shape[1]
grid = (batch, head_num, triton.cdiv(max_kv_cache_len, BLOCK))
num_warps = 4 if k_head_dim <= 64 else 8
num_warps = 2
if alibi is not None:
_token_attn_1_alibi_kernel[grid](
q,
k,
sm_scale,
alibi,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seqlen,
max_kv_cache_len,
attn_out,
kv_cache_loc.stride(0),
kv_cache_loc.stride(1),
q.stride(0),
q.stride(1),
q.stride(2),
k.stride(0),
k.stride(1),
k.stride(2),
attn_out.stride(0),
attn_out.stride(1),
HEAD_DIM=k_head_dim,
BLOCK_N=BLOCK,
num_warps=num_warps,
num_stages=1,
)
else:
_token_attn_1_kernel[grid](
q,
k,
sm_scale,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seqlen,
max_kv_cache_len,
attn_out,
kv_cache_loc.stride(0),
kv_cache_loc.stride(1),
q.stride(0),
q.stride(1),
q.stride(2),
k.stride(0),
k.stride(1),
k.stride(2),
attn_out.stride(0),
attn_out.stride(1),
HEAD_DIM=k_head_dim,
BLOCK_N=BLOCK,
num_warps=num_warps,
num_stages=1,
)
return
@triton.jit
def _token_attn_softmax_fwd(
softmax_logics,
kv_cache_start_loc,
kv_cache_seqlen,
softmax_prob_out,
logics_head_dim_stride,
logics_batch_stride,
prob_head_dim_stride,
prob_batch_stride,
BLOCK_SIZE: tl.constexpr,
):
current_batch = tl.program_id(0)
current_head = tl.program_id(1)
col_offsets = tl.arange(0, BLOCK_SIZE)
current_batch_seq_len = tl.load(kv_cache_seqlen + current_batch)
current_batch_in_all_start_index = tl.load(kv_cache_start_loc + current_batch)
row = tl.load(
softmax_logics
+ current_head * logics_head_dim_stride
+ (current_batch_in_all_start_index + col_offsets) * logics_batch_stride,
mask=col_offsets < current_batch_seq_len,
other=-float("inf"),
).to(tl.float32)
row_minus_max = row - tl.max(row, axis=0)
numerator = tl.exp(row_minus_max)
denominator = tl.sum(numerator, axis=0)
softmax_output = numerator / denominator
tl.store(
softmax_prob_out
+ current_head * prob_head_dim_stride
+ (current_batch_in_all_start_index + col_offsets) * prob_batch_stride,
softmax_output,
mask=col_offsets < current_batch_seq_len,
)
return
@torch.no_grad()
def token_attn_softmax_fwd(softmax_logics, kv_cache_start_loc, kv_cache_seqlen, softmax_prob_out, max_kv_cache_len):
BLOCK_SIZE = triton.next_power_of_2(max_kv_cache_len)
batch, head_num = kv_cache_start_loc.shape[0], softmax_logics.shape[0]
num_warps = 4
if BLOCK_SIZE >= 2048:
num_warps = 8
if BLOCK_SIZE >= 4096:
num_warps = 16
_token_attn_softmax_fwd[(batch, head_num)](
softmax_logics,
kv_cache_start_loc,
kv_cache_seqlen,
softmax_prob_out,
softmax_logics.stride(0),
softmax_logics.stride(1),
softmax_prob_out.stride(0),
softmax_prob_out.stride(1),
num_warps=num_warps,
BLOCK_SIZE=BLOCK_SIZE,
)
return
@triton.jit
def _token_attn_2_kernel(
Prob,
V,
attn_out,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seqlen,
max_kv_cache_len,
kv_cache_loc_b_stride,
kv_cache_loc_s_stride,
prob_head_dim_stride,
prob_batch_stride,
v_batch_stride,
v_head_stride,
v_head_dim_stride,
attn_out_batch_stride,
attn_out_head_stride,
attn_out_head_dim_stride,
HEAD_DIM: tl.constexpr,
BLOCK_N: tl.constexpr,
):
current_batch = tl.program_id(0)
current_head = tl.program_id(1)
offs_n = tl.arange(0, BLOCK_N)
offs_d = tl.arange(0, HEAD_DIM)
current_batch_seq_len = tl.load(kv_cache_seqlen + current_batch)
current_batch_start_index = max_kv_cache_len - current_batch_seq_len
current_batch_in_all_start_index = tl.load(kv_cache_start_loc + current_batch)
v_loc_off = current_batch * kv_cache_loc_b_stride + (current_batch_start_index + offs_n) * kv_cache_loc_s_stride
p_offs = current_head * prob_head_dim_stride + (current_batch_in_all_start_index + offs_n) * prob_batch_stride
v_offs = current_head * v_head_stride + offs_d[None, :] * v_head_dim_stride
acc = tl.zeros([HEAD_DIM], dtype=tl.float32)
for start_n in range(0, current_batch_seq_len, BLOCK_N):
start_n = tl.multiple_of(start_n, BLOCK_N)
p_value = tl.load(
Prob + p_offs + start_n * kv_cache_loc_s_stride,
mask=(start_n + offs_n) < current_batch_seq_len,
other=0.0,
)
v_loc = tl.load(
kv_cache_loc + v_loc_off + start_n * kv_cache_loc_s_stride,
mask=(start_n + offs_n) < current_batch_seq_len,
other=0.0,
)
v_value = tl.load(
V + v_offs + v_loc[:, None] * v_batch_stride,
mask=(start_n + offs_n[:, None]) < current_batch_seq_len,
other=0.0,
)
acc += tl.sum(p_value[:, None] * v_value, 0)
acc = acc.to(tl.float16)
off_o = (
current_batch * attn_out_batch_stride
+ current_head * attn_out_head_stride
+ offs_d * attn_out_head_dim_stride
)
out_ptrs = attn_out + off_o
tl.store(out_ptrs, acc)
return
@torch.no_grad()
def token_attn_fwd_2(prob, v, attn_out, kv_cache_loc, kv_cache_start_loc, kv_cache_seqlen, max_kv_cache_len):
if triton.__version__ >= "2.1.0":
BLOCK = 128
else:
BLOCK = 64
batch, head = kv_cache_loc.shape[0], v.shape[1]
grid = (batch, head)
num_warps = 4
dim = v.shape[-1]
_token_attn_2_kernel[grid](
prob,
v,
attn_out,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seqlen,
max_kv_cache_len,
kv_cache_loc.stride(0),
kv_cache_loc.stride(1),
prob.stride(0),
prob.stride(1),
v.stride(0),
v.stride(1),
v.stride(2),
attn_out.stride(0),
attn_out.stride(1),
attn_out.stride(2),
HEAD_DIM=dim,
BLOCK_N=BLOCK,
num_warps=num_warps,
num_stages=1,
)
return
@torch.no_grad()
def token_attention_fwd(
q, k, v, attn_out, kv_cache_loc, kv_cache_start_loc, kv_cache_seq_len, max_len_in_batch, alibi=None
):
head_num = k.shape[1]
batch_size = kv_cache_seq_len.shape[0]
calcu_shape1 = (batch_size, head_num, k.shape[2])
total_token_num = k.shape[0]
att_m_tensor = torch.empty((head_num, total_token_num), dtype=q.dtype, device="cuda")
token_attn_fwd_1(
q.view(calcu_shape1),
k,
att_m_tensor,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seq_len,
max_len_in_batch,
alibi=alibi,
)
prob = torch.empty_like(att_m_tensor)
token_attn_softmax_fwd(att_m_tensor, kv_cache_start_loc, kv_cache_seq_len, prob, max_len_in_batch)
att_m_tensor = None
token_attn_fwd_2(
prob, v, attn_out.view(calcu_shape1), kv_cache_loc, kv_cache_start_loc, kv_cache_seq_len, max_len_in_batch
)
prob = None
return
class Llama2TokenAttentionForwards:
@staticmethod
@triton.jit
def _fwd_kernel(
Logics,
V,
Out,
B_Loc,
B_Start_Loc,
B_Seqlen,
max_input_len,
stride_logic_h,
stride_logic_bs,
stride_vbs,
stride_vh,
stride_vd,
stride_obs,
stride_oh,
stride_od,
stride_b_loc_b,
stride_b_loc_s,
other_kv_index, # avoid nan information
kv_group_num,
BLOCK_DMODEL: tl.constexpr,
BLOCK_N: tl.constexpr,
):
cur_batch = tl.program_id(0)
cur_head = tl.program_id(1)
cur_kv_head = cur_head // kv_group_num
cur_batch_seq_len = tl.load(B_Seqlen + cur_batch)
cur_batch_start_loc = tl.load(B_Start_Loc + cur_batch)
offs_n = tl.arange(0, BLOCK_N)
offs_d = tl.arange(0, BLOCK_DMODEL)
off_v = cur_kv_head * stride_vh + offs_d[None, :] * stride_vd
off_b_loc = cur_batch * stride_b_loc_b + (max_input_len - cur_batch_seq_len) * stride_b_loc_s
v_ptrs = V + off_v
e_max = float("-inf")
e_sum = 0.0
acc = tl.zeros([BLOCK_DMODEL], dtype=tl.float32)
for start_n in range(0, cur_batch_seq_len, BLOCK_N):
start_n = tl.multiple_of(start_n, BLOCK_N)
v_index = tl.load(
B_Loc + off_b_loc + (start_n + offs_n) * stride_b_loc_s,
mask=(start_n + offs_n) < cur_batch_seq_len,
other=other_kv_index,
)
qk = tl.load(
Logics + cur_head * stride_logic_h + (cur_batch_start_loc + start_n + offs_n) * stride_logic_bs,
mask=start_n + offs_n < cur_batch_seq_len,
other=float("-inf"),
)
n_e_max = tl.maximum(tl.max(qk, 0), e_max)
old_scale = tl.exp(e_max - n_e_max)
p = tl.exp(qk - n_e_max)
e_sum = e_sum * old_scale + tl.sum(p, 0)
v = tl.load(v_ptrs + v_index[:, None] * stride_vbs)
acc = acc * old_scale + tl.sum(p[:, None] * v, 0)
e_max = n_e_max
acc = acc / e_sum
off_o = cur_batch * stride_obs + cur_head * stride_oh + offs_d * stride_od
out_ptrs = Out + off_o
tl.store(out_ptrs, acc)
return
@staticmethod
@torch.no_grad()
def token_softmax_reducev_fwd(logics, v, o, b_loc, b_start_loc, b_seq_len, max_input_len, other_kv_index):
BLOCK = 64
batch, head = b_seq_len.shape[0], logics.shape[0]
grid = (batch, head)
kv_group_num = logics.shape[0] // v.shape[1]
num_warps = 1
Llama2TokenAttentionForwards._fwd_kernel[grid](
logics,
v,
o,
b_loc,
b_start_loc,
b_seq_len,
max_input_len,
logics.stride(0),
logics.stride(1),
v.stride(0),
v.stride(1),
v.stride(2),
o.stride(0),
o.stride(1),
o.stride(2),
b_loc.stride(0),
b_loc.stride(1),
other_kv_index,
kv_group_num,
BLOCK_DMODEL=v.shape[-1],
BLOCK_N=BLOCK,
num_warps=num_warps,
num_stages=3,
)
return
@staticmethod
@triton.jit
def _fwd_kernel_token_softmax(
Logics,
B_Start_Loc,
B_Seqlen,
Prob_Out,
stride_logic_h,
stride_logic_bs,
stride_prob_h,
stride_prob_bs,
BLOCK_SIZE: tl.constexpr,
):
cur_batch = tl.program_id(0)
cur_head = tl.program_id(1)
col_offsets = tl.arange(0, BLOCK_SIZE)
cur_batch_seq_len = tl.load(B_Seqlen + cur_batch)
cur_batch_in_all_start_index = tl.load(B_Start_Loc + cur_batch)
row = tl.load(
Logics + cur_head * stride_logic_h + (cur_batch_in_all_start_index + col_offsets) * stride_logic_bs,
mask=col_offsets < cur_batch_seq_len,
other=-float("inf"),
).to(tl.float32)
row_minus_max = row - tl.max(row, axis=0)
numerator = tl.exp(row_minus_max)
denominator = tl.sum(numerator, axis=0)
softmax_output = numerator / denominator
tl.store(
Prob_Out + cur_head * stride_prob_h + (cur_batch_in_all_start_index + col_offsets) * stride_prob_bs,
softmax_output,
mask=col_offsets < cur_batch_seq_len,
)
return
@staticmethod
@torch.no_grad()
def token_softmax_fwd(Logics, B_Start_Loc, B_Seqlen, Prob_Out, max_input_len):
BLOCK_SIZE = triton.next_power_of_2(max_input_len)
batch, head_num = B_Start_Loc.shape[0], Logics.shape[0]
num_warps = 4
if BLOCK_SIZE >= 2048:
num_warps = 8
if BLOCK_SIZE >= 4096:
num_warps = 16
Llama2TokenAttentionForwards._fwd_kernel_token_softmax[(batch, head_num)](
Logics,
B_Start_Loc,
B_Seqlen,
Prob_Out,
Logics.stride(0),
Logics.stride(1),
Prob_Out.stride(0),
Prob_Out.stride(1),
num_warps=num_warps,
BLOCK_SIZE=BLOCK_SIZE,
)
return
@staticmethod
@triton.jit
def _fwd_kernel_token_att1(
Q,
K,
sm_scale,
B_Loc,
B_Start_Loc,
B_Seqlen,
max_input_len,
Att_Out,
stride_b_loc_b,
stride_b_loc_s,
stride_qbs,
stride_qh,
stride_qd,
stride_kbs,
stride_kh,
stride_kd,
att_stride_h,
att_stride_bs,
kv_group_num,
BLOCK_DMODEL: tl.constexpr,
BLOCK_N: tl.constexpr,
):
cur_batch = tl.program_id(0)
cur_head = tl.program_id(1)
start_n = tl.program_id(2)
cur_kv_head = cur_head // kv_group_num
offs_d = tl.arange(0, BLOCK_DMODEL)
cur_batch_seq_len = tl.load(B_Seqlen + cur_batch)
cur_batch_in_all_start_index = tl.load(B_Start_Loc + cur_batch)
cur_batch_start_index = max_input_len - cur_batch_seq_len
cur_batch_end_index = max_input_len
off_q = cur_batch * stride_qbs + cur_head * stride_qh + offs_d * stride_qd
offs_n = start_n * BLOCK_N + tl.arange(0, BLOCK_N)
block_stard_index = start_n * BLOCK_N
block_mask = tl.where(block_stard_index < cur_batch_seq_len, 1, 0)
for start_mark in range(0, block_mask, 1):
q = tl.load(Q + off_q + start_mark)
offs_n_new = cur_batch_start_index + offs_n
k_loc = tl.load(
B_Loc + stride_b_loc_b * cur_batch + stride_b_loc_s * offs_n_new,
mask=offs_n_new < cur_batch_end_index,
other=0,
)
off_k = k_loc[:, None] * stride_kbs + cur_kv_head * stride_kh + offs_d[None, :] * stride_kd
k = tl.load(K + off_k, mask=offs_n_new[:, None] < cur_batch_end_index, other=0.0)
att_value = tl.sum(q[None, :] * k, 1)
att_value *= sm_scale
off_o = cur_head * att_stride_h + (cur_batch_in_all_start_index + offs_n) * att_stride_bs
tl.store(Att_Out + off_o, att_value, mask=offs_n_new < cur_batch_end_index)
return
@staticmethod
@torch.no_grad()
def token_att_fwd(q, k, att_out, B_Loc, B_Start_Loc, B_Seqlen, max_input_len):
BLOCK = 32
# shape constraints
Lq, Lk = q.shape[-1], k.shape[-1]
assert Lq == Lk
assert Lk in {16, 32, 64, 128}
sm_scale = 1.0 / (Lk**0.5)
batch, head_num = B_Loc.shape[0], q.shape[1]
grid = (batch, head_num, triton.cdiv(max_input_len, BLOCK))
kv_group_num = q.shape[1] // k.shape[1]
num_warps = 4 if Lk <= 64 else 8
num_warps = 2
Llama2TokenAttentionForwards._fwd_kernel_token_att1[grid](
q,
k,
sm_scale,
B_Loc,
B_Start_Loc,
B_Seqlen,
max_input_len,
att_out,
B_Loc.stride(0),
B_Loc.stride(1),
q.stride(0),
q.stride(1),
q.stride(2),
k.stride(0),
k.stride(1),
k.stride(2),
att_out.stride(0),
att_out.stride(1),
kv_group_num=kv_group_num,
BLOCK_DMODEL=Lk,
BLOCK_N=BLOCK,
num_warps=num_warps,
num_stages=1,
)
return
@staticmethod
@triton.jit
def _fwd_kernel_token_att2(
Prob,
V,
Out,
B_Loc,
B_Start_Loc,
B_Seqlen,
max_input_len, # B_Start_Loc cumsum of input lens if continuous
stride_b_loc_b,
stride_b_loc_s,
stride_ph,
stride_pbs,
stride_vbs,
stride_vh,
stride_vd,
stride_obs,
stride_oh,
stride_od,
kv_group_num,
BLOCK_DMODEL: tl.constexpr,
BLOCK_N: tl.constexpr,
):
cur_batch = tl.program_id(0)
cur_head = tl.program_id(1)
cur_kv_head = cur_head // kv_group_num
offs_n = tl.arange(0, BLOCK_N)
offs_d = tl.arange(0, BLOCK_DMODEL)
cur_batch_seq_len = tl.load(B_Seqlen + cur_batch)
cur_batch_start_index = max_input_len - cur_batch_seq_len
cur_batch_in_all_start_index = tl.load(B_Start_Loc + cur_batch)
v_loc_off = cur_batch * stride_b_loc_b + (cur_batch_start_index + offs_n) * stride_b_loc_s
p_offs = cur_head * stride_ph + (cur_batch_in_all_start_index + offs_n) * stride_pbs
v_offs = cur_kv_head * stride_vh + offs_d[None, :] * stride_vd
acc = tl.zeros([BLOCK_DMODEL], dtype=tl.float32)
for start_n in range(0, cur_batch_seq_len, BLOCK_N):
start_n = tl.multiple_of(start_n, BLOCK_N)
p_value = tl.load(
Prob + p_offs + start_n * stride_b_loc_s, mask=(start_n + offs_n) < cur_batch_seq_len, other=0.0
)
v_loc = tl.load(
B_Loc + v_loc_off + start_n * stride_b_loc_s, mask=(start_n + offs_n) < cur_batch_seq_len, other=0.0
)
v_value = tl.load(
V + v_offs + v_loc[:, None] * stride_vbs,
mask=(start_n + offs_n[:, None]) < cur_batch_seq_len,
other=0.0,
)
acc += tl.sum(p_value[:, None] * v_value, 0)
acc = acc.to(tl.float16)
off_o = cur_batch * stride_obs + cur_head * stride_oh + offs_d * stride_od
out_ptrs = Out + off_o
tl.store(out_ptrs, acc)
return
@staticmethod
@torch.no_grad()
def token_att_fwd2(prob, v, out, B_Loc, B_Start_Loc, B_Seqlen, max_input_len):
if triton.__version__ >= "2.1.0":
BLOCK = 128
else:
BLOCK = 64
batch, head = B_Loc.shape[0], prob.shape[0]
grid = (batch, head)
num_warps = 4
dim = v.shape[-1]
kv_group_num = prob.shape[0] // v.shape[1]
Llama2TokenAttentionForwards._fwd_kernel_token_att2[grid](
prob,
v,
out,
B_Loc,
B_Start_Loc,
B_Seqlen,
max_input_len,
B_Loc.stride(0),
B_Loc.stride(1),
prob.stride(0),
prob.stride(1),
v.stride(0),
v.stride(1),
v.stride(2),
out.stride(0),
out.stride(1),
out.stride(2),
kv_group_num=kv_group_num,
BLOCK_DMODEL=dim,
BLOCK_N=BLOCK,
num_warps=num_warps,
num_stages=1,
)
return
# this is the interface of llama2 attn forward
@staticmethod
@torch.no_grad()
def token_attn(
q, k, v, attn_out, kv_cache_loc, kv_cache_start_loc, kv_cache_seq_len, max_len_in_batch, other_kv_index
):
total_token_num = k.shape[0]
batch_size, head_num, head_dim = q.shape
calcu_shape1 = (batch_size, head_num, head_dim)
att_m_tensor = torch.empty((head_num, total_token_num), dtype=q.dtype, device="cuda")
Llama2TokenAttentionForwards.token_att_fwd(
q,
k,
att_m_tensor,
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seq_len,
max_len_in_batch,
)
if triton.__version__ == "2.0.0":
prob = torch.empty_like(att_m_tensor)
Llama2TokenAttentionForwards.token_softmax_fwd(
att_m_tensor, kv_cache_start_loc, kv_cache_seq_len, prob, max_len_in_batch
)
att_m_tensor = None
Llama2TokenAttentionForwards.token_att_fwd2(
prob,
v,
attn_out.view(calcu_shape1),
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seq_len,
max_len_in_batch,
)
prob = None
return
elif triton.__version__ >= "2.1.0":
Llama2TokenAttentionForwards.token_softmax_reducev_fwd(
att_m_tensor,
v,
attn_out.view(calcu_shape1),
kv_cache_loc,
kv_cache_start_loc,
kv_cache_seq_len,
max_len_in_batch,
other_kv_index,
)
else:
raise Exception("not support triton version")