[$] Custom page-cache policies with BPF
At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Tal Zussman discussed improving the kernel's page cache to better serve specific workloads. He highlighted the limitations of current eviction policies, particularly for applications with mixed workloads, such as financial databases. Zussman proposed a new feature called cache_ext, which would allow user-defined page-cache policies to be implemented via BPF programs without requiring kernel changes.
- ▪The kernel's page cache is crucial for system performance, managing data copies from the filesystem.
- ▪Current eviction methods, like least-recently-used, may not effectively serve all workloads, particularly those with high-priority and analytical tasks.
- ▪Zussman's proposed cache_ext feature would enable customizable page-cache policies through BPF programs, enhancing flexibility.
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Did you know...? LWN.net is a subscriber-supported publication; we rely on subscribers to keep the entire operation going. Please help out by buying a subscription and keeping LWN on the net. By Jonathan CorbetMay 22, 2026 LSFMM+BPF The kernel's page cache is charged with maintaining pages (or, more correctly, folios) containing copies of data from files in the filesystem; its performance has a big effect on the performance of the system as a whole. One of the key decisions the kernel must make is when to evict folios from the page cache. At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Tal Zussman ran a memory-management-track session on how the page cache could be better customized for specific workloads.
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