Linux Swap Table Code Shows The Potential For Huge Performance Gains

A new set of 27 Linux kernel patches introduces a "Swap Tables" mechanism aimed at enhancing virtual memory management. As Phoronix's Michael Larabel reports, "the hope is for lower memory use, higher performance, dynamic swap allocation and growth, greater extensibility, and other improvements over the existing swap code within the Linux kernel." From the report: Engineer Kairui Song with Tencent posted the Swap Table patch series today for implementing the design ideas discussed in recent months by kernel developers. The results are very exciting so let's get straight to it: "With this series, swap subsystem will have a ~20-30% performance gain from basic sequential swap to heavy workloads, for both 4K and mTHP folios. The idle memory usage is already much lower, the average memory consumption is still the same or will also be even lower (with further works). And this enables many more future optimizations, with better defined swap operations." "The patches also clean-up and address various historical issues with the SWAP subsystem," notes Larabel. Context: In Linux, swap space acts as an overflow for RAM, storing inactive memory pages on disk to free up RAM for active processes. Traditional swap mechanisms are limited in flexibility and performance. The proposed "Swap Tables" aim to address these issues by allowing more efficient and dynamic management of swap space, potentially leading to better system responsiveness and resource utilization. Read more of this story at Slashdot.

May 17, 2025 - 02:00

Linux Swap Table Code Shows The Potential For Huge Performance Gains

A new set of 27 Linux kernel patches introduces a "Swap Tables" mechanism aimed at enhancing virtual memory management. As Phoronix's Michael Larabel reports, "the hope is for lower memory use, higher performance, dynamic swap allocation and growth, greater extensibility, and other improvements over the existing swap code within the Linux kernel." From the report: Engineer Kairui Song with Tencent posted the Swap Table patch series today for implementing the design ideas discussed in recent months by kernel developers. The results are very exciting so let's get straight to it: "With this series, swap subsystem will have a ~20-30% performance gain from basic sequential swap to heavy workloads, for both 4K and mTHP folios. The idle memory usage is already much lower, the average memory consumption is still the same or will also be even lower (with further works). And this enables many more future optimizations, with better defined swap operations." "The patches also clean-up and address various historical issues with the SWAP subsystem," notes Larabel. Context: In Linux, swap space acts as an overflow for RAM, storing inactive memory pages on disk to free up RAM for active processes. Traditional swap mechanisms are limited in flexibility and performance. The proposed "Swap Tables" aim to address these issues by allowing more efficient and dynamic management of swap space, potentially leading to better system responsiveness and resource utilization.