Linux 5.18 To Bring RISC-V sv57 Support For 5-Level Page Tables

Written by Michael Larabel in RISC-V on 25 February 2022 at 06:00 AM EST. 1 Comment
It was just with Linux 5.17 that its RISC-V code adds "sv48" support for being able to handle more system memory by offering 48-bit virtual address space support. Now for Linux 5.17 there is "sv57" support prepared for 57-bit virtual address space support with five level page table handling.

Queued up in the Linux RISC-V's "for-next" branch over the past week is support for the sv57 extension this royalty-free processor ISA. RISC-V sv57 allows for 57-bit page-based virtual memory system support for cases where the sv48 support is insufficient. The sv57 extension adds the fifth level of the page table.

The sv57 extension underwent its public review in late 2021. The sv57 support is now in riscv's for-next branch ahead of the Linux 5.18 merge window opening next month. The sv57 support is enabled by default and will fall-back to sv48 / 4 level page tables in cases where the platform does not support sv57. In turn Linux then also falls back to 3 level page tables when sv48 is not supported.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

Popular News This Week