Files
sglang/test/registered/unit
laoyao0822 d015e3fb01 Reduce CP shared KV current-chunk materialization
Phase 2 shared KV keeps persistent KV/index sharded across CP ranks but
uses a full-view compatibility layer before NSA topk and MLA attention.
For current-only prefill chunks, the current KV/index tensors have already
been CP all-gathered and reranged before being written to the sharded
persistent pool. This change adds a guarded current-reuse path that remaps
logical current locs to compact tensor rows and skips the shared-KV
materialize path for current-only MLA and NSA indexer reads.

Constraint: Existing NSA/MLA kernels still consume full-view/compact page tables; history and mixed current/history batches must keep the Phase 2 fallback.
Rejected: Make all history attention shard-aware in this patch | that requires global topk merge and distributed sparse attention and belongs to a later phase.
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Do not remove the Phase 2 fallback until mixed/history shared-KV paths have correctness and performance coverage.
Tested: python -m py_compile on modified Python files
Tested: git diff --check on staged modified files
Not-tested: local pytest collection is blocked by missing pybase64 in this environment.
Not-tested: full long-context chunked prefill/decode performance in this commit step.
2026-04-26 23:29:34 +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.