Linus Torvalds Lands 2.6% Performance Improvement with Minor Linux Kernel Patch

Linus Torvalds has successfully merged a minor patch to the Linux kernel that achieves a 2.6% performance improvement in Intel's "will it scale" per-thread-ops benchmark. The patch, which consists of 21 lines of code, modifies the 64-bit copy_from_user() function by eliminating the use of barrier_nospec(), a slow operation. Instead, it employs pointer masking to handle invalid addresses more efficiently. This change is expected to enhance performance in copying data from user-space to kernel-space, although its broader impact on various workloads remains to be seen. The optimization is particularly significant as it reduces the overhead associated with Spectre mitigations, which have previously imposed performance costs. The patch is set to be included in the upcoming Linux 6.12-rc6 kernel release, with the stable version expected later in November.

- Linus Torvalds' patch improves Linux kernel performance by 2.6%.

- The optimization focuses on the 64-bit copy_from_user() function.

- The patch eliminates the slow barrier_nospec() operation.

- It will be included in the Linux 6.12-rc6 release.

- The change aims to reduce performance costs associated with Spectre mitigations.