Files
sglang/test/registered/unit
laoyao0822 b17976b60d Keep CP HiCache free room from collapsing under cache reuse
Repeated GSM8K/cache-hit traffic can drain a CP owner lane while exact
allocation still succeeds. This changes L1/L2 free-room logic so the trigger
accounts for the pending allocation, then evicts a minimum target chunk or the
exact shortage, whichever is larger. CP load-back also performs best-effort
owner-lane free-room eviction before admitting tiny cache hits that would
otherwise skew one lane.

The commit also adds gated bs>1 prefill timing markers around
recv/bootstrap/batch/inflight polling so future hangs expose the scheduler
boundary instead of only surfacing as a watchdog shutdown. The post-fix repeat
GSM8K failure is recorded as an active regression to continue investigating,
not as old-process noise.

Constraint: Free-room policy must reduce repeated eviction and owner-lane starvation without reserving required+target pages after every allocation
Rejected: Evict to required+target availability | wastes L1/L2 residency under many short cache hits
Rejected: Treat free-room misses as fatal on load-back | exact capacity should remain the strict admission condition
Confidence: medium
Scope-risk: moderate
Directive: Do not remove the gated bs>1 timing markers until repeat-GSM8K hangs have a direct failing boundary
Tested: git diff --check
Tested: python -m py_compile for touched Python files
Tested: remote earlier test_cp_shared_kv_layout.py and test_cp_hicache_metadata.py passed 157 tests after this free-room formula
Not-tested: Two full repeat GSM8K runs after this commit; latest repeat still killed prefill and requires follow-up root-cause work
2026-06-07 01:23:34 +08:00
..

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

  1. Find the source file under python/sglang/srt/.
  2. 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
    
  3. 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")
    
  4. Run locally:
    pytest test/registered/unit/ -v            # all unit tests
    pytest test/registered/unit/mem_cache/ -v  # one module
    
  5. 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() or Engine(...).
  • No model weight loading.
  • Use CustomTestCase (from sglang.test.test_utils, adds CI retry).
  • Use unittest.mock for dependencies that are expensive to construct.