[None][feat] Enforce multimodal encoder runtime budgets with budgeted output storage

[yechank-nvidia]

Description

Multimodal encoder work is unbounded at runtime today: the scheduler admits on
LLM/KV capacity alone, so one iteration can submit more encoder items — or more
encoder attention tokens — than the workspace was sized for, and the embeddings
held between encode and prefill accumulate with no cap. KV-cache sizing at
startup does not know any of it exists.

This PR makes encoder execution a scheduled, budgeted resource:

• Scheduling. encoder_max_num_items × encoder_max_num_tokens are
  enforced per iteration over atomic items (one image or video), selected FCFS;
  a request left partial resumes later. The executor's encoder step is the
  single encode site.
• Memory. A byte budget bounds the embeddings held between encode and
  prefill. A request's first scheduled item allocates one contiguous buffer for
  all of its items, so a started request can always finish; KV estimation
  reserves that budget at startup. A request that could never fit is rejected at
  admission with a message naming the knob, instead of becoming a CUDA OOM.
• multimodal_config.encoder_scheduling_policy selects DEFAULT, EAGER
  (advance encoder work for capacity-rejected requests), or DISABLED (legacy
  inline encode).

Models: Qwen2-VL / Qwen2.5-VL, Qwen3-VL (deepstack-widened rows), Mistral3 /
Pixtral.

Measurements

Qwen3-VL-8B-Instruct, 1×H200, aiperf, n=8 per policy, policy the only
difference and kv_cache_config.max_tokens pinned equal. Caches off.

Availability — past the headroom, removing the cap does not degrade: it
loses essentially every request and the server process dies.

KV pinned	DISABLED	DEFAULT
101 GiB	128/128	128/128
105 GiB	one instance served, an independent one died	128/128
108 GiB	0/128, process dead	128/128, no OOM

Reproduced on two hosts. At 105 GiB DISABLED is non-deterministic.

Peak memory — DEFAULT has zero variance across repetitions and barely
moves as the workload gets 7× heavier (136.1 / 135.9 / 135.1 GiB at 1 / 4 / 7
images per request); DISABLED tracks the traffic (131.7 → 138.0 → 138.1).

Latency — a trade, and only under heavy load:

Workload	TTFT avg	ITL avg
4 images, conc 32	+2.0%	−0.5%
7 images, conc 32	−12.3%	+12.2%

At 7 images both are real (non-overlapping ranges). DEFAULT raises the fast
ITL percentiles and lowers the slow ones (p50 +17%, p99 −2.0%) — spreading
encoder work across iterations. Quote both halves or neither.

Test coverage

test_multimodal_scheduler.py (atomic packing, byte-budget
allocate-before-compute, whole-request charging, admission fail-fast, per-item
cache read-through, contiguous-buffer ownership, per-rank resolution under PP),
test_kv_cache_estimation.py (encoder profiled at its own budget; reservation
of unmaterialized capacity), test_modeling_qwen2_5vl.py /
test_modeling_mistral.py (capacity from processor geometry, window counts
matching the encoder's padding, dummy tensors satisfying the encoder contract),
test_scheduler_serializable_output.py (item schedule survives rank
distribution).

Follow-ups

Unify the remaining full-request consumers (side-stream prefetch,
mm_encoder_only / disagg, non-item models) onto the item path and
single-source the item manifest; TODO markers are anchored at the migration
sites.

Dev Engineer Review

• Adds FCFS multimodal encoder item scheduling with item, token, and resident-output byte budgets.
• Adds partial request progress, contiguous embedding storage, cache reuse, admission rejection, and centralized executor encoding.
• Adds DEFAULT, EAGER, and DISABLED scheduling policies.
• Updates Qwen2-VL, Qwen2.5-VL, Qwen3-VL, Mistral3, Pixtral, and shared encoder capacity handling.
• Replaces encoder_max_batch_size with encoder_max_num_items across APIs, configuration, telemetry, manifests, and documentation.
• Adds typed item metadata, cache-key helpers, raw-input cleanup, and public exports.
• Review focus: verify setup_attn_metadata callers, budget calculations, admission behavior, cache reuse, and partial-progress handling.
• No test-list files were changed.

QA Engineer Review

• Added and updated tests for scheduler selection, FCFS ordering, eager scheduling, admission, token limits, byte limits, request progress, storage, output validation, cache reuse, serialization, metadata handling, input cleanup, KV-cache estimation, and encoder capacity calculations.
• Added model-specific coverage for Qwen2-VL, Qwen2.5-VL, Qwen3-VL, Mistral3, Pixtral, Gemma4, RADIO, and SigLIP.
• Replaced obsolete get_dummy_mm_data_for_tokens tests with coverage for get_dummy_mm_data.
• No files under tests/integration/test_lists/ were modified.
• The changed tests are not registered in test-db/ or qa/ based on the provided changes.
• Verdict: needs follow-up.

[yechank-nvidia]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #66452 [ run ] triggered by Bot. Commit: ef0b537 Link to invocation

[tensorrt-cicd]

PR_Github #66409 [ run ] completed with state ABORTED. Commit: c91a392

Link to invocation

[tensorrt-cicd]

PR_Github #66452 [ run ] completed with state SUCCESS. Commit: ef0b537
/LLM/main/L0_MergeRequest_PR pipeline #54094 completed with status: 'FAILURE'

CI Report

⚠️ Action Required:

• Please check the failed tests and fix your PR
• If you cannot view the failures, ask the CI triggerer to share details
• Once fixed, request an NVIDIA team member to trigger CI again

CI Agent Failure Analysis

Link to invocation

[yechank-nvidia]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #66479 [ run ] triggered by Bot. Commit: ef0b537 Link to invocation

[tensorrt-cicd]

PR_Github #66479 [ run ] completed with state SUCCESS. Commit: ef0b537
/LLM/main/L0_MergeRequest_PR pipeline #54120 completed with status: 'UNSTABLE'

CI Report

⚠️ Multi-GPU Label Required:
Multi-GPU tests require the ci: full pre-merge approved label on this PR. Ask a member of NVIDIA/trt-llm-ci-approvers to add the label, then re-trigger CI with the same bot command (no rebase needed).

⚠️ Action Required:

• Please check the failed tests and fix your PR
• If you cannot view the failures, ask the CI triggerer to share details
• Once fixed, request an NVIDIA team member to trigger CI again

Link to invocation

[yechank-nvidia]

/bot help

[github-actions]

GitHub Bot Help

/bot [-h] ['run', 'kill', 'skip', 'reuse-pipeline'] ...

Provide a user friendly way for developers to interact with a Jenkins server.

Run /bot [-h|--help] to print this help message.

See details below for each supported subcommand.

Details

run [--reuse-test (optional)pipeline-id --disable-fail-fast --skip-test --stage-list "A10-PyTorch-1, xxx" --gpu-type "A30, H100_PCIe" --test-backend "pytorch, cpp" --add-multi-gpu-test --only-multi-gpu-test --disable-multi-gpu-test --post-merge --extra-stage "H100_PCIe-TensorRT-Post-Merge-1, xxx" --detailed-log --debug(experimental) --high-priority]

Launch build/test pipelines. All previously running jobs will be killed.

--reuse-test (optional)pipeline-id (OPTIONAL) : Allow the new pipeline to reuse build artifacts and skip successful test stages from a specified pipeline or the last pipeline if no pipeline-id is indicated. If the Git commit ID has changed, this option will be always ignored. The DEFAULT behavior of the bot is to reuse build artifacts and successful test results from the last pipeline.

--disable-reuse-test (OPTIONAL) : Explicitly prevent the pipeline from reusing build artifacts and skipping successful test stages from a previous pipeline. Ensure that all builds and tests are run regardless of previous successes.

--disable-fail-fast (OPTIONAL) : Disable fail fast on build/tests/infra failures.

--skip-test (OPTIONAL) : Skip all test stages, but still run build stages, package stages and sanity check stages. Note: Does NOT update GitHub check status.

--stage-list "A10-PyTorch-1, xxx" (OPTIONAL) : Only run the specified test stages. Supports wildcard * for pattern matching (e.g., "*PerfSanity*" matches all stages containing PerfSanity). Examples: "A10-PyTorch-1, xxx", "PerfSanity". The patterns "*", "*Post-Merge*", and "*PerfSanity*", including equivalent escaped or repeated-star forms and their use in comma-separated lists, require the ci: post-merge approved PR label. Note: Does NOT update GitHub check status.

--gpu-type "A30, H100_PCIe" (OPTIONAL) : Only run the test stages on the specified GPU types. Examples: "A30, H100_PCIe". Note: Does NOT update GitHub check status.

--test-backend "pytorch, cpp" (OPTIONAL) : Skip test stages which don't match the specified backends. Only support [pytorch, cpp, tensorrt, triton]. Examples: "pytorch, cpp" (does not run test stages with tensorrt or triton backend). Note: Does NOT update GitHub pipeline status.

--only-multi-gpu-test (OPTIONAL) : Only run the multi-GPU tests. Requires the ci: full pre-merge approved label on the PR (ask a member of NVIDIA/trt-llm-ci-approvers). Note: Does NOT update GitHub check status.

--disable-multi-gpu-test (OPTIONAL) : Disable the multi-GPU tests. Note: Does NOT update GitHub check status.

--add-multi-gpu-test (OPTIONAL) : Force run the multi-GPU tests in addition to running L0 pre-merge pipeline. Requires the ci: full pre-merge approved label on the PR (ask a member of NVIDIA/trt-llm-ci-approvers).

--post-merge (OPTIONAL) : Run the L0 post-merge pipeline instead of the ordinary L0 pre-merge pipeline. Requires the ci: post-merge approved PR label applied by an active member of NVIDIA/trt-llm-ci-approvers. The approval label remains in place when new commits are pushed.

--extra-stage "H100_PCIe-TensorRT-Post-Merge-1, xxx" (OPTIONAL) : Run the ordinary L0 pre-merge pipeline and specified test stages. Supports wildcard * for pattern matching. Examples: --extra-stage "H100_PCIe-TensorRT-Post-Merge-1, xxx", --extra-stage "Post-Merge". The patterns "*", "*Post-Merge*", and "*PerfSanity*", including equivalent escaped or repeated-star forms and their use in comma-separated lists, require the ci: post-merge approved PR label.

--detailed-log (OPTIONAL) : Enable flushing out all logs to the Jenkins console. This will significantly increase the log volume and may slow down the job.

--debug (OPTIONAL) : Experimental feature. Enable access to the CI container for debugging purpose. Note: Specify exactly one stage in the stage-list parameter to access the appropriate container environment. Note: Does NOT update GitHub check status.

--high-priority (OPTIONAL) : Run the pipeline with high priority. This option is restricted to authorized users only and will route the job to a high-priority queue.

kill

kill

Kill all running builds associated with pull request.

skip

skip --comment COMMENT

Skip testing for latest commit on pull request. --comment "Reason for skipping build/test" is required. IMPORTANT NOTE: This is dangerous since lack of user care and validation can cause top of tree to break.

reuse-pipeline

reuse-pipeline

Reuse a previous pipeline to validate current commit. This action will also kill all currently running builds associated with the pull request. IMPORTANT NOTE: This is dangerous since lack of user care and validation can cause top of tree to break.

[yechank-nvidia]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #66532 [ run ] triggered by Bot. Commit: ef0b537 Link to invocation

[tensorrt-cicd]

PR_Github #66532 [ run ] completed with state SUCCESS. Commit: ef0b537
/LLM/main/L0_MergeRequest_PR pipeline #54165 completed with status: 'SUCCESS'
Pipeline passed with automatic retried tests. Check the rerun report for details.

CI Report

Link to invocation