CP HiCache write reservations must stay per radix node, but the transfer descriptor does not need to be per request. This changes the layer-end hook to group pending write states for the same source and layer, so bs>1 prefill emits one target D2H descriptor and one draft D2H descriptor per layer while preserving per-node metadata, rollback, and ack semantics.\n\nConstraint: CP shared-KV HiCache metadata, host slots, and radix acknowledgements remain per request/node.\nConstraint: TAI direct transfer kernels already accept flattened page descriptors, so no tai-kernel change is required.\nRejected: Merge HiCache reservations or radix nodes | would complicate rollback and split handling.\nRejected: Add collective synchronization for grouped backup | grouping is local descriptor construction and must not add rank-level sync.\nConfidence: high\nScope-risk: moderate\nDirective: Keep target and draft source notifications separate; final ack must wait for both when draft HiCache is attached.\nTested: local py_compile for cache_controller.py and test_hicache_controller_cp.py\nTested: local git diff --check\nTested: remote pytest test/registered/unit/managers/test_hicache_controller_cp.py test/registered/unit/mem_cache/test_cp_hicache_load_back_owner_lanes.py => 85 passed, 3 warnings\nNot-tested: full ETE bs>1 CP HiCache replay with admission gate removed\nNot-tested: Nsight/throughput validation of reduced D2H submit count
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.