[Perf]remove unnecessary padding before MLA V1 prefill #917
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Angazenn
changed the title
Signed-off-by: angazenn <zengyanjia@huawei.com>
ganyi1996ppo
approved these changes
May 23, 2025
ganyi1996ppo
changed the title
momo609
pushed a commit
to momo609/vllm-ascend
that referenced
this pull request
May 30, 2025
…ject#917) <!-- Thanks for sending a pull request! BEFORE SUBMITTING, PLEASE READ https://docs.vllm.ai/en/latest/contributing/overview.html --> ### What this PR does / why we need it? Currently, the implementation for MLA V1 pads q, k, v to `head_dim` 256 to conform to early MLA kernel. But the new MLA kernel supports `head_dim` that can't be devided by 128. Therefore we can remove those unnecessary paddings to boost the performance ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? <!-- CI passed with new added/existing test. If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future. If tests were not added, please describe why they were not added and/or why it was difficult to add. --> Signed-off-by: angazenn <zengyanjia@huawei.com> Co-authored-by: angazenn <zengyanjia@huawei.com> Signed-off-by: wangxiaoxin (A) <w00664509@china.huawei.com>
chopper0126
pushed a commit
to chopper0126/vllm-ascend
that referenced
this pull request
Oct 16, 2025
…ject#917) <!-- Thanks for sending a pull request! BEFORE SUBMITTING, PLEASE READ https://docs.vllm.ai/en/latest/contributing/overview.html --> ### What this PR does / why we need it? Currently, the implementation for MLA V1 pads q, k, v to `head_dim` 256 to conform to early MLA kernel. But the new MLA kernel supports `head_dim` that can't be devided by 128. Therefore we can remove those unnecessary paddings to boost the performance ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? <!-- CI passed with new added/existing test. If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future. If tests were not added, please describe why they were not added and/or why it was difficult to add. --> Signed-off-by: angazenn <zengyanjia@huawei.com> Co-authored-by: angazenn <zengyanjia@huawei.com>
Angazenn
added a commit
to Angazenn/vllm-ascend
that referenced
this pull request
Oct 21, 2025
…ject#917) <!-- Thanks for sending a pull request! BEFORE SUBMITTING, PLEASE READ https://docs.vllm.ai/en/latest/contributing/overview.html --> ### What this PR does / why we need it? Currently, the implementation for MLA V1 pads q, k, v to `head_dim` 256 to conform to early MLA kernel. But the new MLA kernel supports `head_dim` that can't be devided by 128. Therefore we can remove those unnecessary paddings to boost the performance ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? <!-- CI passed with new added/existing test. If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future. If tests were not added, please describe why they were not added and/or why it was difficult to add. --> Signed-off-by: angazenn <zengyanjia@huawei.com> Co-authored-by: angazenn <zengyanjia@huawei.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
What this PR does / why we need it?
Currently, the implementation for MLA V1 pads q, k, v to
head_dim256 to conform to early MLA kernel. But the new MLA kernel supportshead_dimthat can't be devided by 128. Therefore we can remove those unnecessary paddings to boost the performanceDoes this PR introduce any user-facing change?
No.
How was this patch tested?