Linux 5.14 Supports Some Exciting Features With RISC-V

The RISC-V architecture code supports more functionality with the in-development Linux 5.14 kernel.

First up, with Linux 5.14 RISC-V now supports transparent hugepages. Transparent hugepages for reducing TLB overhead for page look-ups and helping out performance particularly for systems/servers with large amounts of RAM can now work on RISC-V. All of the kernel code is in place for this forthcoming kernel.

KFENCE is also now supported on RISC-V as the Kernel Electric Fence for memory safety error detection/validation. KFENCE was merged back in Linux 5.12 but not supported on RISC-V until now.

This kernel also adds RISC-V support for generic PCI resources mapping, support for the mem= kernel parameter, optimized copy_to_user and copy_from_user handling, and a variety of other fixes and minor improvements.

The optimized copy_to_user/copy_from_user handling for Linux 5.14 is set to "reduce CPU usage dramatically" within kernel space particularly for system calls with large buffers. The optimization is around unaligned memory access handling.

The full list of RISC-V feature changes for Linux 5.14 can be found via this PR.

Elsewhere in the kernel, OpenRISC meanwhile is working on better driver support.