2026-04-27-the-evolution-of-flashattention#131
2026-04-27-the-evolution-of-flashattention#131emharsha1812 wants to merge 10 commits intoiclr-blogposts:mainfrom
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You can only add/change/remove files related to your post, i.e. files that match one of these patterns: <_posts/SLUG.md, assets/img/SLUG/..., assets/html/SLUG/..., assets/bibliography/SLUG.bib>. But we found that you changed the following: <.gitignore>. Also, make sure your PR's title (2026-04-27-the-evolution-of-flashattention) matches your post's slug! Please make the aforementioned changes and re-submit :) |
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Pull request overview
This PR adds a new (future-dated) Distill blog post on FlashAttention’s evolution, along with supporting bibliography and figures.
Changes:
- Add the post
_posts/2026-04-27-the-evolution-of-flashattention.mdwith detailed technical content and citations. - Add a per-post BibTeX file
assets/bibliography/2026-04-27-the-evolution-of-flashattention.bib. - Add/update figure asset(s) and tweak
.gitignore.
Reviewed changes
Copilot reviewed 2 out of 18 changed files in this pull request and generated 7 comments.
| File | Description |
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assets/img/2026-04-27-the-evolution-of-flashattention/Figure_8.png |
Adds/updates an image used in the post’s complexity analysis section. |
assets/bibliography/2026-04-27-the-evolution-of-flashattention.bib |
Adds the bibliography backing the post’s <d-cite> references. |
.gitignore |
Fixes .idea entry formatting and adds .github/skills/ to ignore list. |
_posts/2026-04-27-the-evolution-of-flashattention.md |
Adds the new Distill post content and citation usage. |
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| Finally, numerical precision is a tunable parameter, not a fixed constraint. FlashAttention-3's block quantization and FA4's software-based exponential approximation demonstrate that carefully managed low-precision computation can maintain accuracy while improving throughput. Future algorithms might adaptively select precision per-operation based on numerical sensitivity analysis, potentially using FP8 or FP4 for matmuls while maintaining higher precision only where gradients demand it. | ||
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| However, these principles come with a sobering caveat: the usability wall remains high. Writing a custom attention kernel that achieves even 50% of hardware peak requires deep expertise in GPU memory hierarchies, warp scheduling, Tensor Core constraints, and low-level CUDA or PTX programming. This excludes most ML researchers from contributing to or modifying these kernels directly. Tools like Triton <d-cite key="tillet2019triton"></d-cite>, ThunderKittens <d-cite key="spector2024thunderkittenssimplefastadorable"></d-cite>, and CuTe aim to lower this barrier by providing higher-level abstractions, but a significant gap remains between algorithm design on paper and efficient GPU implementation. Closing this gap—through better DSLs, compilers, or automated tuning—is as important as the algorithmic advances themselves. |
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The post cites tillet2019triton, but that citation key is not present in assets/bibliography/2026-04-27-the-evolution-of-flashattention.bib (searching the bibliography yields no matches). This will break citation rendering/build for the post; add a BibTeX entry for Triton (or update the cite key to an existing entry).
| However, these principles come with a sobering caveat: the usability wall remains high. Writing a custom attention kernel that achieves even 50% of hardware peak requires deep expertise in GPU memory hierarchies, warp scheduling, Tensor Core constraints, and low-level CUDA or PTX programming. This excludes most ML researchers from contributing to or modifying these kernels directly. Tools like Triton <d-cite key="tillet2019triton"></d-cite>, ThunderKittens <d-cite key="spector2024thunderkittenssimplefastadorable"></d-cite>, and CuTe aim to lower this barrier by providing higher-level abstractions, but a significant gap remains between algorithm design on paper and efficient GPU implementation. Closing this gap—through better DSLs, compilers, or automated tuning—is as important as the algorithmic advances themselves. | |
| However, these principles come with a sobering caveat: the usability wall remains high. Writing a custom attention kernel that achieves even 50% of hardware peak requires deep expertise in GPU memory hierarchies, warp scheduling, Tensor Core constraints, and low-level CUDA or PTX programming. This excludes most ML researchers from contributing to or modifying these kernels directly. Tools like Triton, ThunderKittens <d-cite key="spector2024thunderkittenssimplefastadorable"></d-cite>, and CuTe aim to lower this barrier by providing higher-level abstractions, but a significant gap remains between algorithm design on paper and efficient GPU implementation. Closing this gap—through better DSLs, compilers, or automated tuning—is as important as the algorithmic advances themselves. |
| eprint={2009.14794}, | ||
| archivePrefix={arXiv}, | ||
| primaryClass={cs.LG}, | ||
| url={https://arxiv.org/abs/2009.14794}, | ||
| } |
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This BibTeX entry closes at line 180, but additional fields and a stray closing brace follow (lines 181–185). As written, the bibliography file is syntactically invalid and will fail to parse; remove the dangling lines or merge them correctly into the juravsky2024... entry.
| eprint={2009.14794}, | |
| archivePrefix={arXiv}, | |
| primaryClass={cs.LG}, | |
| url={https://arxiv.org/abs/2009.14794}, | |
| } |
| eprint={2009.14794}, | ||
| archivePrefix={arXiv}, | ||
| primaryClass={cs.LG}, | ||
| url={https://arxiv.org/abs/2009.14794}, | ||
| } |
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These lines appear to be leftover BibTeX fields (eprint, archivePrefix, etc.) plus an extra closing brace that are not attached to any entry. This makes the bibliography invalid; delete them or move them inside the intended @article{...} block.
| eprint={2009.14794}, | |
| archivePrefix={arXiv}, | |
| primaryClass={cs.LG}, | |
| url={https://arxiv.org/abs/2009.14794}, | |
| } |
| @misc{kwon2023efficientmemorymanagementlarge, | ||
| title={Efficient Memory Management for Large Language Model Serving with PagedAttention}, | ||
| author={Woosuk Kwon and Zhuohan Li and Siyuan Zhuang and Ying Sheng and Lianmin Zheng and Cody Hao Yu and Joseph E. Gonzalez and Hao Zhang and Ion Stoica}, | ||
| year={2023}, | ||
| eprint={2309.06180}, | ||
| archivePrefix={arXiv}, | ||
| primaryClass={cs.LG}, | ||
| url={https://arxiv.org/abs/2309.06180}, | ||
| } |
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Duplicate BibTeX key kwon2023efficientmemorymanagementlarge is defined earlier in this file (as an @article at lines 168–173) and then redefined here as an @misc. Duplicate keys typically cause BibTeX/Jekyll-Scholar parsing errors or nondeterministic citation resolution; keep a single entry per key (or rename one of them).
| @misc{juravsky2024hydragenhighthroughputllminference, | ||
| title={Hydragen: High-Throughput LLM Inference with Shared Prefixes}, | ||
| author={Jordan Juravsky and Bradley Brown and Ryan Ehrlich and Daniel Y. Fu and Christopher R{\'e} and Azalia Mirhoseini}, | ||
| year={2024}, | ||
| eprint={2402.05099}, | ||
| archivePrefix={arXiv}, | ||
| primaryClass={cs.LG}, | ||
| url={https://arxiv.org/abs/2402.05099}, | ||
| } |
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Duplicate BibTeX key juravsky2024hydragenhighthroughputllminference is defined earlier in this file (as an @article at lines 175–180) and then redefined here as an @misc. Duplicate keys can break bibliography generation; consolidate into a single canonical entry or rename one of the keys.
| @online{gpu-mode-fa4, | ||
| title = {How FlashAttention 4 Works}, | ||
| author = {GPU Mode}, | ||
| year = {2025}, | ||
| url = {https://youtu.be/ZIEq-WTquy4}, | ||
| note = {YouTube video, accessed 2025-12-07} | ||
| } | ||
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| @online{tri-dao-hotchips, | ||
| title = {Domain-Specific Languages for GPU Kernels and Automatic Kernel Authoring with LLMs}, | ||
| author = {Tri Dao}, | ||
| year = {2024}, | ||
| url = {https://youtu.be/_sRkawqEMCs}, | ||
| note = {Hot Chips talk, YouTube, accessed 2025-12-07} | ||
| } |
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This section redefines several BibTeX keys that already exist earlier in the file (e.g., gpu-mode-fa4, tri-dao-hotchips, modal-fa4, wu-fa4-medium). Duplicate keys usually cause BibTeX/Jekyll-Scholar failures; remove the earlier placeholder entries (the ones with YOUR_VIDEO_ID) or rename keys so each citation key is unique.
| @article{schraudolph1999fast, | ||
| title={A fast, compact approximation of the exponential function}, | ||
| author={Schraudolph, Nicol N}, | ||
| journal={Neural Computation}, | ||
| volume={11}, | ||
| number={4}, | ||
| pages={853--862}, | ||
| year={1999}, | ||
| publisher={MIT Press One Rogers Street, Cambridge, MA 02142-1209, USA journals-info~…} | ||
| } | ||
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There was a problem hiding this comment.
Duplicate BibTeX key schraudolph1999fast is defined earlier in the file (lines 157–166) and then redefined again here with different publisher text. Duplicate keys can break bibliography generation; keep one entry and delete or rename the other.
| @article{schraudolph1999fast, | |
| title={A fast, compact approximation of the exponential function}, | |
| author={Schraudolph, Nicol N}, | |
| journal={Neural Computation}, | |
| volume={11}, | |
| number={4}, | |
| pages={853--862}, | |
| year={1999}, | |
| publisher={MIT Press One Rogers Street, Cambridge, MA 02142-1209, USA journals-info~…} | |
| } |
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You can only add/change/remove files related to your post, i.e. files that match one of these patterns: <_posts/SLUG.md, assets/img/SLUG/..., assets/html/SLUG/..., assets/bibliography/SLUG.bib>. But we found that you changed the following: <.gitignore>. Also, make sure your PR's title (2026-04-27-the-evolution-of-flashattention) matches your post's slug! Please make the aforementioned changes and re-submit :) |
OpenReview Submission Thread
https://openreview.net/forum?id=4V2kHdynFN
Checklist before opening a PR
I am opening a pull request against the
mainbranch of the2026repo.My post and all associated references to it are all lowercase, i.e
The title of my PR is exactly the name of my markdown file
_posts/2026-04-27-the-evolution-of-flashattention.mdrequires PR name2026-04-27-the-evolution-of-flashattentionI have anonymized my post: my author's list is
Anonymous, and there is no potentialcontent which can reveal my/my collaborators identities.
My post matches the formatting requirements, including (but not limited to):
your PR automatically being closed!):
_posts/2026-04-27-the-evolution-of-flashattention. mdassets/img/2026-04-27-the-evolution-of-flashattention/assets/bibliography/2026-04-27-the-evolution-of-flashattention.bibdescriptionfield of my front-mattertocfield of my front-matter.bibtexfile as per the sample postAny other comments
Initial submission for ICLR 2026 blog post track.