Files
llama.cpp/tools/server/tests/unit/test_ctx_shift.py
Johannes Gäßler e81b8e4b7f llama: use FA + max. GPU layers by default (#15434)
* llama: use max. GPU layers by default, auto -fa

* ggml-backend: abort instead of segfault
2025-08-30 16:32:10 +02:00

85 lines
2.7 KiB
Python

import pytest
from utils import *
server = ServerPreset.tinyllama2()
LONG_TEXT = """
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
""".strip()
@pytest.fixture(autouse=True)
def create_server():
global server
server = ServerPreset.tinyllama2()
server.n_ctx = 512
server.n_slots = 2
server.n_predict = 128
def test_ctx_shift_enabled():
# the prompt is 301 tokens
# the slot context is 512/2 = 256 tokens
# the prompt is truncated to keep the last (301 - 256/2) = 173 tokens
# 96 tokens are generated thanks to shifting the context when it gets full
global server
server.enable_ctx_shift = True
server.start()
res = server.make_request("POST", "/completion", data={
"n_predict": 96,
"prompt": LONG_TEXT,
})
assert res.status_code == 200
assert res.body["timings"]["prompt_n"] == 173
assert res.body["timings"]["predicted_n"] == 96
assert res.body["truncated"] is True
@pytest.mark.parametrize("n_predict,n_token_output,truncated", [
(64, 64, False),
(-1, 120, True),
])
def test_ctx_shift_disabled_short_prompt(n_predict: int, n_token_output: int, truncated: bool):
global server
server.n_predict = -1
server.start()
res = server.make_request("POST", "/completion", data={
"n_predict": n_predict,
"prompt": "Hi how are you",
})
assert res.status_code == 200
assert res.body["timings"]["predicted_n"] == n_token_output
assert res.body["truncated"] == truncated
def test_ctx_shift_disabled_long_prompt():
global server
server.start()
res = server.make_request("POST", "/completion", data={
"n_predict": 64,
"prompt": LONG_TEXT,
})
assert res.status_code != 200
assert "error" in res.body
assert "exceeds the available context size" in res.body["error"]["message"]
def test_ctx_shift_disabled_stream():
global server
server.start()
res = server.make_stream_request("POST", "/v1/completions", data={
"n_predict": 256,
"prompt": "Once",
"stream": True,
})
content = ""
for data in res:
choice = data["choices"][0]
if choice["finish_reason"] == "length":
assert len(content) > 0
else:
assert choice["finish_reason"] is None
content += choice["text"]