Files
sglang/test/registered/unit
laoyao0822andOmX 4342de0463 Avoid redundant CP collectives on sync shared-KV materialize
Synchronous CP shared KV full-hit and partial-current paths can now use the tai-kernel CUDA IPC slot-dense materialize path instead of first copying local owner pages and then running a dense CP all-reduce. This keeps the async prefetch pipeline unchanged while routing the safer synchronous runtime path through descriptor-driven owner-page reads.

The runtime builds descriptors from the existing page-aligned slot contract, caches peer pointer tables for long-lived KV/index buffers, and falls back with explicit warnings if the tai-kernel IPC capability is missing. Unit coverage locks offset handle exchange, descriptor construction, and both MLA/index full and partial-current calls.

Constraint: Async prefetch currently has unresolved scheduling contention with GEMM/MoE and current-layer KV collectives, so this commit intentionally does not wire IPC into prefetch.

Constraint: tai-kernel must provide offset-aware CUDA IPC symbols from af9fb67.

Rejected: Replace prefetch all-reduce in this slice | Nsight shows prefetch timing and communicator contention need a separate scheduling design.

Rejected: Fail-fast on missing tai IPC immediately | remote ETE still needs to validate production deployment capability before removing the warning fallback.

Confidence: medium

Scope-risk: moderate

Directive: Keep prefetch and synchronous materialize decisions separate until prefetch has a low-SM/copy-engine schedule.

Related: tai-kernel af9fb67

Tested: git diff --check; remote runtime/unit evidence recorded in docs/advanced_features/nsa_prefill_cp_page_aligned_cache_contract.md.

Not-tested: Fresh GLM5 ETE after this commit; async prefetch IPC path.

Co-authored-by: OmX <omx@oh-my-codex.dev>
2026-06-01 00:00:15 +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.