Prefix materialize prefetch has fixed launch and coordination overhead, so tiny cache-hit prefixes should stay on the simpler synchronous path. The default threshold is now expressed as a cached import-time token threshold while the existing page override remains available for workload-specific tuning. Both MLA and index prefix prefetchers use the same page-size-aware threshold, so CP shared-KV prefix prefetch is enabled only when the prefix covers at least one page per CP lane and at least the configured token threshold. Constraint: The default token threshold must be read once to avoid hot-path env lookups Constraint: Existing page threshold override must continue to disable or force the gate Rejected: Hard-code 1024 tokens | tuning needs to be possible without code changes Rejected: Read token threshold on every maybe_create call | unnecessary hot-path env lookup Confidence: medium Scope-risk: narrow Directive: Keep MLA and index prefetch threshold logic shared; do not let their gates diverge Tested: Not rerun per user request; prior py_compile, diff check, and isolated env-cache check had passed before commit Not-tested: full pytest in local environment due missing optional dependencies/kernel import constraints Not-tested: GLM5 E2E throughput after this threshold change
Unit Tests
Component-level tests that do not launch a server or load model weights. Tests can use CPU or GPU — the key criterion is no server process.
Quick Start
- Find the source file under
python/sglang/srt/. - Create the corresponding test here, mirroring the source tree:
srt/mem_cache/radix_cache.py → unit/mem_cache/test_radix_cache.py srt/sampling/sampling_params.py → unit/sampling/test_sampling_params.py - Register for CI at the top of the file (after imports, before test classes):
from sglang.test.ci.ci_register import register_cpu_ci register_cpu_ci(est_time=5, suite="stage-a-test-cpu") # or: register_cuda_ci(est_time=10, suite="stage-b-test-1-gpu-small") - Run locally:
pytest test/registered/unit/ -v # all unit tests pytest test/registered/unit/mem_cache/ -v # one module - Run with coverage:
# summary pytest test/registered/unit/ --cov --cov-config=.coveragerc -v # PR incremental check (require ≥60% on changed lines) pytest test/registered/unit/ --cov --cov-config=.coveragerc --cov-report=xml diff-cover coverage.xml --compare-branch=origin/main --fail-under=60
Example
"""Unit tests for <module> — no server, no model loading."""
from sglang.test.ci.ci_register import register_cpu_ci
register_cpu_ci(est_time=5, suite="stage-a-test-cpu")
import unittest
from sglang.srt.<module> import TargetClass
from sglang.test.test_utils import CustomTestCase
class TestTargetClass(CustomTestCase):
def test_basic_behavior(self):
obj = TargetClass(...)
self.assertEqual(obj.method(), expected)
if __name__ == "__main__":
unittest.main()
Rules
- No
popen_launch_server()orEngine(...). - No model weight loading.
- Use
CustomTestCase(fromsglang.test.test_utils, adds CI retry). - Use
unittest.mockfor dependencies that are expensive to construct.