text-generation-inference/integration-tests/models/test_flash_llama_fp8_kv_cache.py
Daniël de Kok eab07f746c
Add support for FP8 KV cache scales (#2628)
* Add support for FP8 KV cache scales

Since FP8 only has limited dynamic range, we can scale keys/values
before storing them into the cache (and unscale them in attention). To
avoid rescaling the cache as the absmax values change, good scales are
usually determined per layer using calibration calibration data and stored
in the checkpoint.

This change adds support for for using key-value scales and loading them
from checkpoints in the two most common formats:

- Separate per-layer `k_scale` and `v_scale` scalars.
- Per-layer `kv_scale` scalar (older format).

Currently, scales are only used with an `float8_e4m3fn` cache.

Besides adding support for key/value scales, the `fp8_quantize` function
is also extended to support quantization with a kernel vendored from
vLLM. This is slightly faster than the PyTorch implementation, but also
scales in FP32, potentially improving accuracy.

* Update FP8 KV cache test to use checkpoint with scales

* `can_scale`: check that the attention is flashinfer
2024-10-24 16:36:18 +02:00

80 lines
2.2 KiB
Python

import pytest
@pytest.fixture(scope="module")
def flash_llama_fp8_kv_cache_handle(launcher):
with launcher(
"neuralmagic/Meta-Llama-3-8B-Instruct-FP8-KV",
num_shard=2,
kv_cache_dtype="fp8_e4m3fn",
) as handle:
yield handle
@pytest.fixture(scope="module")
async def flash_llama_fp8_kv_cache(flash_llama_fp8_kv_cache_handle):
await flash_llama_fp8_kv_cache_handle.health(300)
return flash_llama_fp8_kv_cache_handle.client
@pytest.mark.release
@pytest.mark.asyncio
@pytest.mark.private
async def test_flash_llama_fp8_kv_cache(flash_llama_fp8_kv_cache, response_snapshot):
response = await flash_llama_fp8_kv_cache.generate(
"What is deep learning?", max_new_tokens=10, decoder_input_details=True
)
assert (
response.generated_text
== " Deep learning is a subset of machine learning that involves"
)
assert response.details.generated_tokens == 10
assert response == response_snapshot
@pytest.mark.release
@pytest.mark.asyncio
@pytest.mark.private
async def test_flash_llama_fp8_kv_cache_all_params(
flash_llama_fp8_kv_cache, response_snapshot
):
response = await flash_llama_fp8_kv_cache.generate(
"What is deep learning?",
max_new_tokens=10,
repetition_penalty=1.2,
return_full_text=True,
stop_sequences=["test"],
temperature=0.5,
top_p=0.9,
top_k=10,
truncate=5,
typical_p=0.9,
watermark=True,
decoder_input_details=True,
seed=0,
)
assert response == response_snapshot
@pytest.mark.release
@pytest.mark.asyncio
@pytest.mark.private
async def test_flash_llama_fp8_kv_cache_load(
flash_llama_fp8_kv_cache, generate_load, response_snapshot
):
responses = await generate_load(
flash_llama_fp8_kv_cache, "What is deep learning?", max_new_tokens=10, n=4
)
assert len(responses) == 4
assert (
responses[0].generated_text
== " Deep learning is a subset of machine learning that involves"
)
assert all(
[r.generated_text == responses[0].generated_text for r in responses]
), f"Different messages : {[r.generated_text for r in responses]}"
assert responses == response_snapshot