feat: Add FP8 KV cache support for Triton attention backend (#18882)

This commit is contained in:
Zack Yu
2026-03-02 23:38:34 -08:00
committed by GitHub
parent 62480ebb1b
commit 07b8d763ef
6 changed files with 180 additions and 27 deletions
@@ -251,6 +251,8 @@ class TestTritonAttention(CustomTestCase):
True,
mask_indptr,
max_len_extend,
1.0,
1.0,
)
b_seq_mask_len = b_seq_len_extend * b_seq_len
@@ -286,6 +288,8 @@ class TestTritonAttention(CustomTestCase):
True,
mask_indptr,
max_len_extend,
1.0,
1.0,
)
redundant_attention(
@@ -395,6 +399,8 @@ class TestTritonAttention(CustomTestCase):
is_causal=True,
mask_indptr=None,
max_len_extend=max_len_extend,
k_scale=1.0,
v_scale=1.0,
sliding_window_size=WINDOW_SIZE,
)
@@ -517,6 +523,8 @@ class TestTritonAttention(CustomTestCase):
num_kv_splits,
max_kv_splits,
sm_scale,
1.0,
1.0,
)
# Correctness reference (float32, stable softmax)
@@ -591,6 +599,7 @@ class TestTritonAttention(CustomTestCase):
num_kv_splits,
max_kv_splits,
sm_scale,
1.0,
)
attn_logits1 = torch.empty(
@@ -616,6 +625,7 @@ class TestTritonAttention(CustomTestCase):
num_kv_splits,
max_kv_splits,
sm_scale,
1.0,
)
cos_sim = torch.nn.functional.cosine_similarity(
@@ -722,6 +732,8 @@ class TestTritonAttention(CustomTestCase):
is_causal=True,
mask_indptr=None,
max_len_extend=max_len_extend,
k_scale=1.0,
v_scale=1.0,
)
# Build unified KV indices
@@ -750,6 +762,8 @@ class TestTritonAttention(CustomTestCase):
o_unified,
k_buffer,
v_buffer,
1.0,
1.0,
qo_indptr,
unified_kv_indptr,
unified_kv_indices,
@@ -155,6 +155,8 @@ class TestWaveAttention(unittest.TestCase):
is_causal,
mask_indptr,
max_len_extend,
1.0,
1.0,
)
o_wave = torch.empty(
@@ -240,6 +242,7 @@ class TestWaveAttention(unittest.TestCase):
num_kv_splits,
max_kv_splits,
sm_scale,
1.0,
logit_cap,
)
@@ -0,0 +1,58 @@
import unittest
from types import SimpleNamespace
from urllib.parse import urlparse
from sglang.srt.utils import kill_process_tree
from sglang.test.ci.ci_register import register_cuda_ci
from sglang.test.few_shot_gsm8k import run_eval
from sglang.test.test_utils import (
DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
DEFAULT_URL_FOR_TEST,
CustomTestCase,
popen_launch_server,
)
register_cuda_ci(est_time=520, suite="stage-b-test-large-1-gpu")
class TestFP8KVCacheTritonBackend(CustomTestCase):
@classmethod
def setUpClass(cls):
cls.model = "neuralmagic/Meta-Llama-3-8B-Instruct-FP8-KV"
cls.base_url = DEFAULT_URL_FOR_TEST
cls.process = popen_launch_server(
cls.model,
cls.base_url,
timeout=DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
other_args=[
"--quantization",
"fp8",
"--kv-cache-dtype",
"fp8_e4m3",
"--attention-backend",
"triton",
],
)
@classmethod
def tearDownClass(cls):
kill_process_tree(cls.process.pid)
def test_gsm8k(self):
parsed_url = urlparse(self.base_url)
args = SimpleNamespace(
num_shots=5,
data_path=None,
num_questions=200,
max_new_tokens=512,
parallel=200,
host=f"{parsed_url.scheme}://{parsed_url.hostname}",
port=parsed_url.port,
)
metrics = run_eval(args)
print(f"{metrics=}")
self.assertGreater(metrics["accuracy"], 0.70)
if __name__ == "__main__":
unittest.main()