leavelet
e8e5edb230
Peers only ever read the CURRENT pages of a rank's compose output — the prefix comes straight from the IPC-registered KV pool — so the symm region does not need to hold the whole dense buffer (pool-bound ~2.5 GB double-buffered slab). It now holds one round of current pages in merged-span order (extend-cap-bound, ~58-100 MB), and dense buffers become purely rank-local (plain allocations or the optional local arena; COMPOSE_SYMM no longer requires COMPOSE_ARENA). Exchange per compose call: publish my written current pages dense[page] -> staging[slot i] (slot = the page's batch current index, identical on every rank, so peers address each other's staging with no per-batch handshake), cp_symm_barrier, gather peers' staging[writer][slot] -> dense[page] via the existing src!=dst page gather. Reuse safety keeps the parity-half distance-2 argument, now on the staging. Capacity sizing comes from the admission caps (max_total_extend_tokens / max_batch_requests) with a pool-derived fallback and the SYMM_HEAP_MB override; overflow fails fast (batch-logical, hence rank-uniform). Idea credit: laoyao0822's touched-pages-proportional staging (906ecbe5d4), rebound onto our barrier-gated, group-agreed transport. Validated on g0033 8xH200: 151 unit tests; 8-rank GPU byte-exactness vs compose_v2 across 8 layers (arena on and off, parity halves exercised); benchmark path e (real protocol) byte-exact, current-page exchange 0.196 ms vs 0.354 ms compact-AR isolated. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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.