[AMD] Add MTP support for DeepSeek R1 FP8 MI355X SGLang

[benenzhu]

Summary

This PR adds MTP (Multi-Token Prediction) support for DeepSeek R1 FP8 on MI355X using SGLang with EAGLE speculative decoding.

SGLang's EAGLE implementation uses DeepSeek R1's native MTP weights to speculatively decode 3 additional tokens per forward pass. This PR uses the default EAGLE configurations.

Changes

• Add new benchmark script benchmarks/dsr1_fp8_mi355x_mtp.sh with EAGLE speculative decoding configuration
• Add dsr1-fp8-mi355x-sglang-mtp config entry to .github/configs/amd-master.yaml
• Update runners/launch_mi355x-amds.sh to support SPEC_SUFFIX for MTP script selection
• Add perf-changelog entry documenting the changes

Configuration

• Concurrency sweep: 4 to 128
• Sequence lengths: 1k1k, 1k8k, 8k1k
• TP: 8

New SGLang Arguments

Argument	Value	Description
--speculative-algorithm	EAGLE	Enable MTP speculative decoding
--max-running-requests	CONC * 4	Increased running requests for MTP workload
--cuda-graph-max-bs	CONC * 4	Increased CUDA graph batch size for MTP

[cquil11]

/sweep test-config dsr1-fp8-mi355x-sglang-mtp --config-files .github/configs/amd-master.yaml --runner-config .github/configs/runners.yaml

[github-actions]

@cquil11 Kicking off a sweep.

Run: https://github.com/InferenceMAX/InferenceMAX/actions/runs/21689411588
Command: test-config dsr1-fp8-mi355x-sglang-mtp --config-files .github/configs/amd-master.yaml --runner-config .github/configs/runners.yaml
Pinned ref: 2065877
Approval: not required (trusted collaborator).

[cquil11]

/sweep test-config --config-keys dsr1-fp8-mi355x-sglang-mtp --config-files .github/configs/amd-master.yaml --runner-config .github/configs/runners.yaml

[github-actions]

@cquil11 Kicking off a sweep.

Run: https://github.com/InferenceMAX/InferenceMAX/actions/runs/21689430926
Command: test-config --config-keys dsr1-fp8-mi355x-sglang-mtp --config-files .github/configs/amd-master.yaml --runner-config .github/configs/runners.yaml
Pinned ref: 2065877
Approval: not required (trusted collaborator).

[benenzhu]

/sweep test-config --config-keys dsr1-fp8-mi355x-sglang-mtp --config-files .github/configs/amd-master.yaml --runner-config .github/configs/runners.yaml

Oh, failed with some wired error at graph capture stage. I will convert it to draft and try fix locally then. Also need some tune for the use-chat-template config.
Thanks for your review.

[functionstackx]

@benenzhu is this PR still draft?

[benenzhu]

@benenzhu is this PR still draft?

yeah，i will close it now. still try to fix the errors.