app.py

import streamlit as st

# A100 specs
TFLOPS = 312e12 
GB_S = 1935e9

# in ms
THREAD_OVERHEAD = 0.005

# in ms
def calc_exec_time(comp_flop, mem_bytes):
  exec_time = comp_flop/TFLOPS + mem_bytes/GB_S
  return max(exec_time*1000, THREAD_OVERHEAD)

def qkv_mha_exec(bs, h, n, d):
  flop = 2*bs*1*d*3*d
  nbytes = 2*bs*1*d + 2*3*d*d + 2*bs*1*3*d
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time
     
def qkv_mqa_exec(bs, h, n, d):
  flop = 2*bs*1*d*(1+2/h)*d
  nbytes = 2*bs*1*d + 2*(2/h)*d*d + 2*bs*1*(2/h)*d
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time
  
def att1_mha_exec(bs, h, n, d):
  flop = 2*bs*h*(d/h)*n
  nbytes = 2*bs*h*(d/h) + 2*bs*h*n*(d/h) + 2*bs*h*n
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time
  
def att1_mqa_exec(bs, h, n, d):
  flop = 2*bs*h*(d/h)*n
  nbytes = 2*bs*h*(d/h) + 2*bs*n*(d/h) + 2*bs*h*n
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time

def att2_mha_exec(bs, h, n, d):
  flop = 2*bs*h*n*(d/h)
  nbytes = 2*bs*h*n + 2*bs*h*n*(d/h) + 2*bs*h*(d/h)
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time
  
def att2_mqa_exec(bs, h, n, d):
  flop = 2*bs*h*n*(d/h)
  nbytes = 2*bs*n*(d/h) + 2*bs*n*(d/h) + 2*bs*h*(d/h)
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time
  
def out_exec(bs, h, n, d):
  flop = 2*bs*1*d*d
  nbytes = 2*bs*1*d + 2*d*d + 2*bs*1*d
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time

def softmax_exec(bs, h, n, d):
  flop = 0
  nbytes = 2*bs*h*n + 2*bs*h*n
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time

def ln_exec(bs, h, n, d):
  nbytes = 2*bs*1*d + 2*bs*1*d
  flop = 0
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time

def mlp_exec(bs, h, n, d):
  flop = 2*bs*1*d*4*d
  nbytes = 2*bs*1*d + 2*d*4*d + 2*bs*1*4*d
  exec_time = calc_exec_time(flop, nbytes)
  return flop, nbytes, exec_time
  
def print_kernel_execution(c1, c2, comp_flop, mem_bytes):
  exec_time = calc_exec_time(comp_flop, mem_bytes)
  comp_flop = round(comp_flop/1e9, 2)
  mem_bytes = round(mem_bytes/1e6, 2)
  
  c1.write("GFLOP:")
  c2.write(str(comp_flop))
  c1.write("MB: ")
  c2.write(str(mem_bytes))
  c1.write("Time (ms):")
  c2.write(str(exec_time))
  
  return exec_time



st.sidebar.header("Transformer parameters")
col1, col2 = st.sidebar.columns([2, 4])

bs = st.sidebar.number_input('Batch size', value=10)
h = st.sidebar.number_input('Num heads',value=16)
d = st.sidebar.number_input('Dimension', value=768)
l = st.sidebar.number_input('Num layers', value=24)

n_start = st.sidebar.number_input('Start seq', value=1)
n = st.sidebar.number_input('End seq', value=1024)

st.sidebar.header("GPU parameters")


st.header("Execution time (ms)")

mqa_total_time = 0.
mha_total_time = 0.

for i in range(n_start, n):
  shared_time = out_exec(bs, h, i, d)[2] + softmax_exec(bs, h, i , d)[2] + 2*ln_exec(bs, h, i, d)[2] \
                + 2*mlp_exec(bs, h, i, d)[2] + 3*ln_exec(bs, h, i, d)[2]
  mha_time = shared_time + qkv_mha_exec(bs, h, i, d)[2] + att1_mha_exec(bs, h, i, d)[2] + att2_mha_exec(bs, h, i, d)[2]
  mha_total_time += l*mha_time
  mqa_time = shared_time + qkv_mqa_exec(bs, h, i, d)[2] + att1_mqa_exec(bs, h, i, d)[2] + att2_mqa_exec(bs, h, i, d)[2]
  mqa_total_time += l*mqa_time
  
st.write("Multi-Head Attention: " + str(mha_total_time))
st.write("Multi-Query Attention: " + str(mqa_total_time))
st.write("Speed-up MQA over MHA: " + str(mha_total_time/mqa_total_time))

st.header("Memory consumption")



breakdown = st.checkbox("Show breakdown per layer")
if breakdown:
  st.header('Attention layer')
  
  st.subheader('QKV projection')
  st.caption("Multi-Head Attention")
  mha_flop = 2*bs*1*d*3*d
  mha_bytes = 2*bs*1*d + 2*3*d*d + 2*bs*1*3*d
  c1, c2 = st.columns([2, 3])
  qkv_mha_time = print_kernel_execution(c1, c2, mha_flop, mha_bytes)
  
  st.caption("Multi-Query Attention")
  mqa_flop = 2*bs*1*d*(1+2/h)*d
  mqa_bytes = 2*bs*1*d + 2*(2/h)*d*d + 2*bs*1*(2/h)*d
  c1, c2 = st.columns([2, 3])
  qkv_mqa_time = print_kernel_execution(c1, c2, mqa_flop, mqa_bytes)
  
  st.subheader('QK gemm')
  st.write("Note that calculation depends on sequence length (n)")
  
  st.caption("Multi-Head Attention")
  mha_flop = 2*bs*h*(d/h)*n
  mha_bytes = 2*bs*h*(d/h) + 2*bs*h*n*(d/h) + 2*bs*h*n
  c1, c2 = st.columns([2, 3])
  att1_mha_time = print_kernel_execution(c1, c2, mha_flop, mha_bytes)
  
  st.caption("Multi-Query Attention")
  mqa_flop = 2*bs*h*(d/h)*n
  mqa_bytes = 2*bs*h*(d/h) + 2*bs*n*(d/h) + 2*bs*h*n
  c1, c2 = st.columns([2, 3])
  att1_mqa_time = print_kernel_execution(c1, c2, mqa_flop, mqa_bytes)
  
  st.subheader('Attention-value gemm')
  st.write("Calculation depends on sequence length. We show numbers for maximum sequence length n.")
  st.caption("Multi-Head Attention")
  mha_flop = 2*bs*h*n*(d/h)
  mha_bytes = 2*bs*h*n + 2*bs*h*n*(d/h) + 2*bs*h*(d/h)
  c1, c2 = st.columns([2, 3])
  att2_mha_time = print_kernel_execution(c1, c2, mha_flop, mha_bytes)
  
  st.caption("Multi-Query Attention")
  mqa_flop = 2*bs*h*n*(d/h)
  mqa_bytes = 2*bs*n*(d/h) + 2*bs*n*(d/h) + 2*bs*h*(d/h)
  c1, c2 = st.columns([2, 3])
  att2_mqa_time = print_kernel_execution(c1, c2, mqa_flop, mqa_bytes)
  
  st.subheader('Output projection')
  out_flop = 2*bs*1*d*d
  out_bytes = 2*bs*1*d + 2*d*d + 2*bs*1*d
  c1, c2 = st.columns([2, 3])
  out_time = print_kernel_execution(c1, c2, out_flop, out_bytes)
  
  st.subheader('Element-wise ops')
  st.write("We also need to take into the softmax layer, layer norm, and residual connection. We assume that these operations are memory bound. ")
  
  st.caption("Softmax")
  softmax_bytes = 2*bs*h*n + 2*bs*h*n
  c1, c2 = st.columns([2, 3])
  softmax_time = print_kernel_execution(c1, c2, 0, softmax_bytes)
  
  st.caption("Layer norm/residual connection")
  ln_bytes = 2*bs*1*d
  ln_flop = 0
  ln_time = print_kernel_execution(c1, c2, 0, ln_bytes)
  
  st.header('MLP')
  st.subheader('First Linear')
  mlp1_flop = 2*bs*1*d*4*d
  mlp1_bytes = 2*bs*1*d + 2*d*4*d + 2*bs*1*4*d
  c1, c2 = st.columns([2, 3])
  mlp1_time = print_kernel_execution(c1, c2, mlp1_flop, mlp1_bytes)
  
  st.subheader('Second Linear')
  mlp2_flop = 2*bs*1*d*4*d
  mlp2_bytes = 2*bs*1*d + 2*d*4*d + 2*bs*1*4*d
  c1, c2 = st.columns([2, 3])
  mlp2_time = print_kernel_execution(c1, c2, mlp2_flop, mlp2_bytes)
  
  st.subheader('Element-wise ops')
  st.write("We also need to take into the GeLU, layer norm, and residual connection. We assume that these operations are memory bound. ")
  ln_bytes = 2*bs*1*d
  ln_flop = 0
  ln_time = print_kernel_execution(c1, c2, 0, ln_bytes)