Files
sglang/test/registered/unit
laoyao0822 7284a469a2 Reuse prepared HiCache load descriptors across CP prefill layers
CP shared-KV bs>1 cache-hit loads already merge request load ops, but the host pool still rebuilt layer-invariant mapping work from the same host/device indices. Introduce a PreparedLoadDescriptor lifecycle around begin/end load, wire MLA KV and NSA index H2D loads through tai-kernel prepared submit when available, and add timing hooks plus regression coverage for descriptor reuse and explicit fallback logging. Record the P4/P6b design and benchmark results in the advanced feature notes.

Constraint: Radix residency and allocator decisions remain synchronous; only the data-transfer descriptor is prepared for per-layer async submit.

Constraint: Production fast path must not silently fall back when tai prepared H2D support is missing.

Rejected: Cross-batch descriptor reuse | descriptor lifetime and tensor ownership are only safe within one load operation.

Rejected: Change L2->L1 scheduling to layer-ahead prefetch in this commit | that is a separate lifecycle change after descriptor reuse is stable.

Confidence: medium

Scope-risk: moderate

Directive: Keep LayerDoneCounter per-layer readiness semantics; do not replace with all-layer waits.

Tested: python -m py_compile python/sglang/srt/mem_cache/memory_pool_host.py python/sglang/srt/managers/cache_controller.py

Tested: Remote g0034:cjy-glm5-new PYTHONPATH=python python -m pytest -q test/registered/unit/managers/test_hicache_controller_cp.py (88 passed)

Tested: Remote tai-kernel prepared descriptor CUDA test (6 passed) and P4 benchmark full matrix (90 rows)

Not-tested: ETE replay/GSM8K cache-hit correctness after this commit

Not-tested: Layer-ahead L2->L1 prefetch scheduling

Co-authored-by: OmX <omx@oh-my-codex.dev>
2026-06-11 05:09:41 +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.