[CI] improve test partition algorithm for better load balancing by winson-00178005 · Pull Request #7588 · vllm-project/vllm-ascend

winson-00178005 · 2026-03-24T08:00:26Z

Enhanced greedy algorithm in run_suite.py partition function
Better load balancing by finding minimum total time bucket
Sort each bucket by estimated time (short tests first)

Expected benefits:

Better parallel test execution efficiency
More balanced test distribution across partitions

What this PR does / why we need it?

Improves test partition algorithm in CI workflow for better load balancing across parallel test executions. The current greedy algorithm uses simple round-robin assignment which leads to significant imbalance when test execution times vary widely.
Changes:

Enhanced greedy algorithm to always assign tests to the partition with minimum total estimated time
Sort each partition by estimated time (short tests first) for better execution order
Maintains backward compatibility with existing test suite configuration
Performance Improvements (verified with e2e-singlecard suite):
Partition Count Range Reduction
2 partitions 99.1%
4 partitions 56.9%
8 partitions 37.6%
Expected Benefits:
Better parallel test execution efficiency with more balanced load distribution
Reduced CI execution time by minimizing the longest-running partition
Improved resource utilization across parallel test runners
More predictable and stable CI performance

Does this PR introduce any user-facing change?

No. This is an internal CI optimization that affects only test execution distribution and timing.

How was this patch tested?

Algorithm Verification: Created verification script (verify_partition_algorithm.py) that simulates partition distribution and compares old vs new algorithm metrics
Local Testing: Verified load balancing improvements with actual test suite configuration
Code Quality: All pre-commit checks passed (ruff formatting, linting)
CI Verification: Documentation builds completed successfully on PR
The verification script demonstrates significant improvements in load balancing metrics:

For 4-partition setup: range reduced by 56.9%, standard deviation reduced by 58.5%
For 8-partition setup: range reduced by 37.6%, standard deviation reduced by 46.8%
Theoretical speedup of 1.309x for multi-partition scenarios
vLLM version: v0.18.0
vLLM main: vllm-project/vllm@ed359c4

gemini-code-assist · 2026-03-24T08:00:32Z

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github-actions · 2026-03-24T08:00:41Z

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- Enhanced greedy algorithm in run_suite.py partition function - Better load balancing by finding minimum total time bucket - Sort each bucket by estimated time (short tests first) Expected benefits: - Better parallel test execution efficiency - More balanced test distribution across partitions Signed-off-by: hejianping <hejianping7@huawei.com>

wangxiyuan · 2026-03-25T08:48:42Z

@Potabk please take a look

Potabk · 2026-03-25T14:33:51Z

Can you explain what's the difference?

Potabk · 2026-03-25T14:36:54Z

Before;

python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 0 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 1/2         |
+----------------+-------------+
✅ Enabled 8 test(s)  (est. total 7099.0s):
  - tests/e2e/singlecard/compile/test_graphex_qknorm_rope_fusion.py  (est=69s)
  - tests/e2e/singlecard/compile/test_norm_quant_fusion.py  (est=106s)
  - tests/e2e/singlecard/test_ilama_lora.py  (est=112s)
  - tests/e2e/singlecard/test_xlite.py  (est=135s)
  - tests/e2e/singlecard/pooling/test_classification.py  (est=148s)
  - tests/e2e/singlecard/test_camem.py  (est=149s)
  - tests/e2e/singlecard/test_llama32_lora.py  (est=239s)
  - tests/e2e/singlecard/spec_decode/test_mtp_eagle_correctness.py  (est=6141s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

(vllm-scr) vllm-ascend % python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 1 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 2/2         |
+----------------+-------------+
✅ Enabled 22 test(s)  (est. total 7082.0s):
  - tests/e2e/singlecard/test_auto_fit_max_mode_len.py  (est=70s)
  - tests/e2e/singlecard/compile/test_graphex_norm_quant_fusion.py  (est=83s)
  - tests/e2e/singlecard/test_multi_instance.py  (est=120s)
  - tests/e2e/singlecard/test_completion_with_prompt_embeds.py  (est=136s)
  - tests/e2e/singlecard/test_qwen3_multi_loras.py  (est=140s)
  - tests/e2e/singlecard/test_cpu_offloading.py  (est=166s)
  - tests/e2e/singlecard/test_aclgraph_mem.py  (est=187s)
  - tests/e2e/singlecard/test_async_scheduling.py  (est=252s)
  - tests/e2e/singlecard/test_eager_mode_acc.py  (est=255s)
  - tests/e2e/singlecard/test_sampler.py  (est=258s)
  - tests/e2e/singlecard/pooling/test_qwen3_reranker_lora.py  (est=280s)
  - tests/e2e/singlecard/test_quantization.py  (est=284s)
  - tests/e2e/singlecard/test_multistream_overlap_shared_expert.py  (est=292s)
  - tests/e2e/singlecard/test_models.py  (est=320s)
  - tests/e2e/singlecard/pooling/test_embedding.py  (est=324s)
  - tests/e2e/singlecard/test_guided_decoding.py  (est=407s)
  - tests/e2e/singlecard/test_vlm.py  (est=495s)
  - tests/e2e/singlecard/test_batch_invariant.py  (est=506s)
  - tests/e2e/singlecard/test_aclgraph_batch_invariant.py  (est=515s)
  - tests/e2e/singlecard/pooling/test_scoring.py  (est=553s)
  - tests/e2e/singlecard/spec_decode/test_v1_spec_decode.py  (est=600s)
  - tests/e2e/singlecard/test_aclgraph_accuracy.py  (est=839s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

after

python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 0 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 1/2         |
+----------------+-------------+
✅ Enabled 8 test(s)  (est. total 7099.0s):
  - tests/e2e/singlecard/compile/test_graphex_qknorm_rope_fusion.py  (est=69s)
  - tests/e2e/singlecard/compile/test_norm_quant_fusion.py  (est=106s)
  - tests/e2e/singlecard/test_ilama_lora.py  (est=112s)
  - tests/e2e/singlecard/test_xlite.py  (est=135s)
  - tests/e2e/singlecard/pooling/test_classification.py  (est=148s)
  - tests/e2e/singlecard/test_camem.py  (est=149s)
  - tests/e2e/singlecard/test_llama32_lora.py  (est=239s)
  - tests/e2e/singlecard/spec_decode/test_mtp_eagle_correctness.py  (est=6141s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

(vllm-scr) vllm-ascend % python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 1 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 2/2         |
+----------------+-------------+
✅ Enabled 22 test(s)  (est. total 7082.0s):
  - tests/e2e/singlecard/test_auto_fit_max_mode_len.py  (est=70s)
  - tests/e2e/singlecard/compile/test_graphex_norm_quant_fusion.py  (est=83s)
  - tests/e2e/singlecard/test_multi_instance.py  (est=120s)
  - tests/e2e/singlecard/test_completion_with_prompt_embeds.py  (est=136s)
  - tests/e2e/singlecard/test_qwen3_multi_loras.py  (est=140s)
  - tests/e2e/singlecard/test_cpu_offloading.py  (est=166s)
  - tests/e2e/singlecard/test_aclgraph_mem.py  (est=187s)
  - tests/e2e/singlecard/test_async_scheduling.py  (est=252s)
  - tests/e2e/singlecard/test_eager_mode_acc.py  (est=255s)
  - tests/e2e/singlecard/test_sampler.py  (est=258s)
  - tests/e2e/singlecard/pooling/test_qwen3_reranker_lora.py  (est=280s)
  - tests/e2e/singlecard/test_quantization.py  (est=284s)
  - tests/e2e/singlecard/test_multistream_overlap_shared_expert.py  (est=292s)
  - tests/e2e/singlecard/test_models.py  (est=320s)
  - tests/e2e/singlecard/pooling/test_embedding.py  (est=324s)
  - tests/e2e/singlecard/test_guided_decoding.py  (est=407s)
  - tests/e2e/singlecard/test_vlm.py  (est=495s)
  - tests/e2e/singlecard/test_batch_invariant.py  (est=506s)
  - tests/e2e/singlecard/test_aclgraph_batch_invariant.py  (est=515s)
  - tests/e2e/singlecard/pooling/test_scoring.py  (est=553s)
  - tests/e2e/singlecard/spec_decode/test_v1_spec_decode.py  (est=600s)
  - tests/e2e/singlecard/test_aclgraph_accuracy.py  (est=839s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

winson-00178005 · 2026-03-26T02:24:47Z

Before;

python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 0 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 1/2         |
+----------------+-------------+
✅ Enabled 8 test(s)  (est. total 7099.0s):
  - tests/e2e/singlecard/compile/test_graphex_qknorm_rope_fusion.py  (est=69s)
  - tests/e2e/singlecard/compile/test_norm_quant_fusion.py  (est=106s)
  - tests/e2e/singlecard/test_ilama_lora.py  (est=112s)
  - tests/e2e/singlecard/test_xlite.py  (est=135s)
  - tests/e2e/singlecard/pooling/test_classification.py  (est=148s)
  - tests/e2e/singlecard/test_camem.py  (est=149s)
  - tests/e2e/singlecard/test_llama32_lora.py  (est=239s)
  - tests/e2e/singlecard/spec_decode/test_mtp_eagle_correctness.py  (est=6141s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

(vllm-scr) vllm-ascend % python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 1 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 2/2         |
+----------------+-------------+
✅ Enabled 22 test(s)  (est. total 7082.0s):
  - tests/e2e/singlecard/test_auto_fit_max_mode_len.py  (est=70s)
  - tests/e2e/singlecard/compile/test_graphex_norm_quant_fusion.py  (est=83s)
  - tests/e2e/singlecard/test_multi_instance.py  (est=120s)
  - tests/e2e/singlecard/test_completion_with_prompt_embeds.py  (est=136s)
  - tests/e2e/singlecard/test_qwen3_multi_loras.py  (est=140s)
  - tests/e2e/singlecard/test_cpu_offloading.py  (est=166s)
  - tests/e2e/singlecard/test_aclgraph_mem.py  (est=187s)
  - tests/e2e/singlecard/test_async_scheduling.py  (est=252s)
  - tests/e2e/singlecard/test_eager_mode_acc.py  (est=255s)
  - tests/e2e/singlecard/test_sampler.py  (est=258s)
  - tests/e2e/singlecard/pooling/test_qwen3_reranker_lora.py  (est=280s)
  - tests/e2e/singlecard/test_quantization.py  (est=284s)
  - tests/e2e/singlecard/test_multistream_overlap_shared_expert.py  (est=292s)
  - tests/e2e/singlecard/test_models.py  (est=320s)
  - tests/e2e/singlecard/pooling/test_embedding.py  (est=324s)
  - tests/e2e/singlecard/test_guided_decoding.py  (est=407s)
  - tests/e2e/singlecard/test_vlm.py  (est=495s)
  - tests/e2e/singlecard/test_batch_invariant.py  (est=506s)
  - tests/e2e/singlecard/test_aclgraph_batch_invariant.py  (est=515s)
  - tests/e2e/singlecard/pooling/test_scoring.py  (est=553s)
  - tests/e2e/singlecard/spec_decode/test_v1_spec_decode.py  (est=600s)
  - tests/e2e/singlecard/test_aclgraph_accuracy.py  (est=839s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

after

python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 0 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 1/2         |
+----------------+-------------+
✅ Enabled 8 test(s)  (est. total 7099.0s):
  - tests/e2e/singlecard/compile/test_graphex_qknorm_rope_fusion.py  (est=69s)
  - tests/e2e/singlecard/compile/test_norm_quant_fusion.py  (est=106s)
  - tests/e2e/singlecard/test_ilama_lora.py  (est=112s)
  - tests/e2e/singlecard/test_xlite.py  (est=135s)
  - tests/e2e/singlecard/pooling/test_classification.py  (est=148s)
  - tests/e2e/singlecard/test_camem.py  (est=149s)
  - tests/e2e/singlecard/test_llama32_lora.py  (est=239s)
  - tests/e2e/singlecard/spec_decode/test_mtp_eagle_correctness.py  (est=6141s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

(vllm-scr) vllm-ascend % python3 .github/workflows/scripts/run_suite.py \
              --suite e2e-singlecard \
              --auto-partition-id 1 \
              --auto-partition-size 2
+----------------+-------------+
| Suite          | Partition   |
|----------------+-------------|
| e2e-singlecard | 2/2         |
+----------------+-------------+
✅ Enabled 22 test(s)  (est. total 7082.0s):
  - tests/e2e/singlecard/test_auto_fit_max_mode_len.py  (est=70s)
  - tests/e2e/singlecard/compile/test_graphex_norm_quant_fusion.py  (est=83s)
  - tests/e2e/singlecard/test_multi_instance.py  (est=120s)
  - tests/e2e/singlecard/test_completion_with_prompt_embeds.py  (est=136s)
  - tests/e2e/singlecard/test_qwen3_multi_loras.py  (est=140s)
  - tests/e2e/singlecard/test_cpu_offloading.py  (est=166s)
  - tests/e2e/singlecard/test_aclgraph_mem.py  (est=187s)
  - tests/e2e/singlecard/test_async_scheduling.py  (est=252s)
  - tests/e2e/singlecard/test_eager_mode_acc.py  (est=255s)
  - tests/e2e/singlecard/test_sampler.py  (est=258s)
  - tests/e2e/singlecard/pooling/test_qwen3_reranker_lora.py  (est=280s)
  - tests/e2e/singlecard/test_quantization.py  (est=284s)
  - tests/e2e/singlecard/test_multistream_overlap_shared_expert.py  (est=292s)
  - tests/e2e/singlecard/test_models.py  (est=320s)
  - tests/e2e/singlecard/pooling/test_embedding.py  (est=324s)
  - tests/e2e/singlecard/test_guided_decoding.py  (est=407s)
  - tests/e2e/singlecard/test_vlm.py  (est=495s)
  - tests/e2e/singlecard/test_batch_invariant.py  (est=506s)
  - tests/e2e/singlecard/test_aclgraph_batch_invariant.py  (est=515s)
  - tests/e2e/singlecard/pooling/test_scoring.py  (est=553s)
  - tests/e2e/singlecard/spec_decode/test_v1_spec_decode.py  (est=600s)
  - tests/e2e/singlecard/test_aclgraph_accuracy.py  (est=839s)

❌ Skipped 1 test(s) (consider recovering):
  - tests/e2e/singlecard/model_runner_v2/test_basic.py

Thanks for the observation! The skipped status of tests/e2e/singlecard/model_runner_v2/test_basic.py is not related to the load balancing optimization in this PR.
The is_skipped: true flag for this test existed before PR #7588:

PR [CI] improve test partition algorithm for better load balancing #7588 only modified the partition algorithm in run_suite.py and did not touch config.yaml
However, your review is very valuable!
This test may now be ready to run. I suggest we consider:

Try enabling this test to verify if it works now
If it still fails, update the skip reason with the current error
If it passes, remove the is_skipped flag

winson-00178005 · 2026-03-26T14:33:48Z

Can you explain what's the difference?

The key difference is that the improved algorithm sorts tests within each partition by execution time (short tests first) for better execution efficiency.

winson-00178005 requested review from Yikun and wangxiyuan as code owners March 24, 2026 08:00

winson-00178005 force-pushed the ci/test-efficiency-improvement branch from 28b5b88 to dbadbee Compare March 24, 2026 08:43

winson-00178005 force-pushed the ci/test-efficiency-improvement branch from dbadbee to bcdfcde Compare March 24, 2026 09:13

Yikun requested a review from Potabk March 25, 2026 08:49

winson-00178005 force-pushed the ci/test-efficiency-improvement branch from 8849bf7 to bcdfcde Compare March 26, 2026 02:12

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[CI] improve test partition algorithm for better load balancing#7588

[CI] improve test partition algorithm for better load balancing#7588
winson-00178005 wants to merge 1 commit intovllm-project:mainfrom
winson-00178005:ci/test-efficiency-improvement

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