Linux 6.4 scheduler updates: Addressing performance regression and improving resource usage

The Linux 6.4 scheduler updates released recently are aimed at addressing a performance regression issue that was introduced in Linux 6.3. The regression issue was a result of changes made in "mm_cid," which caused performance issues for PostgreSQL when compared to Linux 6.2. The fix for the regression issue involves tracking the current allocated mm_cid for each mm/cpu instead of immediately freeing it on context switch. This fix went through multiple rounds of review before being included in the Linux 6.4 kernel.

Apart from addressing the performance regression issue, the Linux 6.4 scheduler updates include other changes such as support for unprivileged PSI profiling, improved live-patch stalls, and avoiding selecting throttled tasks to run. These updates are expected to improve system performance and provide better insight into resource usage for non-root users. Users are advised to test their systems before upgrading to the latest kernel version. More details about these updates can be found in the pull request under this article (Official source).