Skip to content

Sparse attention block selection reduced to O(N log N)

A paper published on September 28, 2026 presents hierarchical block selection with LogSumExp, reducing the cost of this step from O(N²) to O(N log N) for long-context models.

By Wendelmaques ·

Source: Block-Sparse Attention com Seleção de Blocos Log-Linear (alphaxiv.org). Text prepared with AI from this source.

What happened and what to do

The paper, published on September 28, 2026, presents a hierarchical method for sparse attention: it scores large context regions with LogSumExp, then recursively narrows selection to promising regions. According to the paper, the approach reduces the cost of block selection from O(N²) to O(N log N) in long-context models.

A company running models with extensive context can evaluate the technique in its own workloads, comparing selection cost, latency, and response quality with its current implementation. This calls for a diagnosis of models and workloads, followed by a controlled test and monitoring to determine whether the change is suitable.

How the consultancy can help

Wendelmaques can diagnose the opportunity across your models and workloads, define an evaluation scope, and implement integration and monitoring on your infrastructure.

Next step

Send a short description of your case to receive a scoped proposal for diagnosis and implementation.

Looking for something else?Frequently asked questionsArticlesContact