The bs>1 path needs index top-k, shared-index prepare, current-index compact, and current-slot compose to consume flattened batch descriptors instead of falling back to per-request or per-segment Python/Torch work. This change wires SGLang to the new TAI batch prepare kernels, keeps fallback explicit, and records the remaining HiCache/load-backup gaps in the bs>1 workstream docs. Constraint: CP shared-KV bs>1 must reuse fast paths rather than adding slow batch-only fallbacks Constraint: No new collective operations were introduced Rejected: Leave current-only cp_index as Python slice/cat | it keeps per-segment overhead in the short-extend bs>1 case Rejected: Infer max segment lengths from CUDA descriptor tensors | .item() would add CPU synchronization on the hot path Confidence: medium Scope-risk: moderate Directive: Do not remove the explicit fallback warnings without verifying the corresponding TAI symbols are present in production Tested: local py_compile for touched SGLang files Tested: remote g0034 test_nsa_cp_utils.py passed, 53 tests Tested: remote g0034 test_fill_current_index_page_slots_uses_tai_kernel_when_available passed Not-tested: full ETE bs>1 traffic with HiCache load/backup and draft/EAGLE enabled
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.