[$] Swap tables, flash-friendly swap, swap_ops, and more
The Linux kernel's swap subsystem has recently gained attention from developers, leading to discussions at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit. Key improvements include reducing overhead in the swap subsystem and optimizing the use of swap cache. Ongoing work aims to address various challenges, including the efficiency of swapping huge pages and the management of swap areas.
- ▪Kairui Song presented recent changes in the swap subsystem, reducing overhead from three to eleven bytes per page down to two to ten bytes.
- ▪There are plans to further optimize the swap subsystem, including efforts to unify folio allocation with the swap cache.
- ▪Challenges remain, such as the inefficiency of swapping PMD-level huge pages and the need for better management of swap areas.
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LWN.net needs you! Without subscribers, LWN would simply not exist. Please consider signing up for a subscription and helping to keep LWN publishing. By Jonathan CorbetMay 18, 2026 LSFMM+BPF The kernel's swap subsystem is charged with managing anonymous pages in secondary storage when those pages are (hopefully) not being used and the memory they occupy is needed elsewhere. This long-unloved subsystem has seen a resurgence of developer interest in recent times, so it is not surprising that it was the topic of three separate sessions in the memory-management track at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit.
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