Increasing throughput with batches and quantization
I have been trying to increase throughput of CogVLM by using batches like other issue here advised and with a A100 I've been able to use a batch size of 16 and output on average 3.5 seconds per image. This still needs to be faster for my use case so I tried other methods and the only one that seemed faster to get to work is to load the model in 4 or 8 bit and increase the batch size, but I can't seem to get the inputs data types correct.I get the following message:
UserWarning: Input type into Linear4bit is torch.float16, but bnb_4bit_compute_type=torch.float32 (default). This will lead to slow inference or training speed.
warnings.warn(f'Input type into Linear4bit is torch.float16, but bnb_4bit_compute_type=torch.float32 (default). This will lead to slow inference or training speed.')
Any other common datatype raises an error... Here's the code:
import torch
import requests
from PIL import Image
from transformers import AutoModelForCausalLM, LlamaTokenizer
import time
import os
tokenizer = LlamaTokenizer.from_pretrained('lmsys/vicuna-7b-v1.5')
model = AutoModelForCausalLM.from_pretrained(
'THUDM/cogvlm-chat-hf',
low_cpu_mem_usage=True,
trust_remote_code=True,
load_in_4bit=True
).eval()
images = os.listdir("/tmp/textcaps/train_images/")
input_list = [model.build_conversation_input_ids(
tokenizer,
images=[Image.open("/tmp/textcaps/train_images/"+i).convert('RGB'),],
query='Describe this image in detail', # Q1
history=[],
)
for i in images[:16]]
def recur_move_to(item, tgt, criterion_func):
if criterion_func(item):
device_copy = item.to(tgt)
return device_copy
elif isinstance(item, list):
return [recur_move_to(v, tgt, criterion_func) for v in item]
elif isinstance(item, tuple):
return tuple([recur_move_to(v, tgt, criterion_func) for v in item])
elif isinstance(item, dict):
return {k: recur_move_to(v, tgt, criterion_func) for k, v in item.items()}
else:
return item
def collate_fn(features, tokenizer) -> dict:
images = [feature.pop('images') for feature in features]
tokenizer.padding_side = 'left'
padded_features = tokenizer.pad(features)
inputs = {**padded_features, 'images': images}
return inputs
input_batch = collate_fn(input_list, tokenizer)
input_batch = recur_move_to(input_batch, 'cuda', lambda x: isinstance(x, torch.Tensor))
input_batch = recur_move_to(input_batch, torch.float16, lambda x: isinstance(x, torch.Tensor) and torch.is_floating_point(x))
gen_kwargs = {"max_length": 2048, "do_sample": False}
t1 = time.time()
with torch.no_grad():
outputs = model.generate(**input_batch, **gen_kwargs)
outputs = outputs[:, input_batch['input_ids'].shape[1]:]
print(tokenizer.batch_decode(outputs))
print(time.time() - t1)
If there are any other suggestions for increasing throughput I am also more than willing to accept. I have a node of 4 A100's and 6 GPUs with 50Gb of memory each.
for the issue mentioned, just use the BitsAndBytesConfig to set the compute type
from transformers import AutoModelForCausalLM, LlamaTokenizer, BitsAndBytesConfig
bnb_config = BitsAndBytesConfig(
load_in_4bit=True,
bnb_4bit_use_double_quant=True,
bnb_4bit_quant_type="nf4",
bnb_4bit_compute_dtype=torch.bfloat16
)
max_memory_mapping = {0: "23GB", 1: "23GB"}
model = AutoModelForCausalLM.from_pretrained(
'THUDM/cogvlm-chat-hf',
low_cpu_mem_usage=True,
trust_remote_code=True,
quantization_config=bnb_config,
max_memory=max_memory_mapping
).eval()
using 4bit quantisation with batch size 16 processing, on an L4 was able to achieve inference time of 4 sec/image. compared to 15s per image without quantisation and batch
I attempted to quantize CogVLM using AutoGPTQ. Quantization was successful, but inference failed.
@neil651 I'm following your BitsAndBytes quantization strategy. It loads fine onto the GPU, but when trying inference I get datatype errors for input vs inference.
File "/home/user/mambaforge/envs/tensorml/lib/python3.11/site-packages/torch/nn/modules/conv.py", line 456, in _conv_forward
return F.conv2d(input, weight, bias, self.stride,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: Input type (c10::BFloat16) and bias type (c10::Half) should be the same
Can you post a whole example of your bitsandbytes 4bit quant with inference?
Just change your image type from bf16 to fp16 is ok.
'images': [[inputs['images'][0].to('cuda').to(torch.float16)]],
@qingsonglv that was the solution to making 4-bit quantized work. With that in place, the model takes up only 12GiB on a 16GB CUDA Nvidia GPU
Repo owners updated quantization to be easier at https://github.com/THUDM/CogVLM/commit/2f293fc6b4063791e80e2bf7e1a045c758352d7e