Linux 4.19.7 Getting Revised STIBP Code, Important PCIe Fix For Radeon GPUs
Some of the notable work to Linux 4.19.7 includes:
- The improved upon STIBP (Single Thread Indirect Branch Predictor) code. After the original STIBP code was back-ported to 4.19, it was quickly reverted due to the large performance impact. Fortunately, being merged to mainline Linux 4.20 Git a few days ago and quickly coming to the 4.19 stable tree is the improved STIBP code where by default this cross-HT Spectre V2 mitigation is only opt-in via prctl and by default for SECCOMP processes. So all is good on the STIBP front for the upcoming Linux 4.19.7.
- Also queued for this next point release is the PCI Express fix to most notably address running newer Radeon GPUs on older PCI Express motherboard. Namely, pairing a PCIe 3.0 graphics card with PCIe 1.0 motherboard was causing various issues, which is now addressed with one of the patches queued for 4.19.7.
- Realtek ALC300 support is also included with this upcoming point release.
The complete list of queued patches for Linux 4.19.7 can be found via this mailing list post. Linux 4.19.7 will be officially released in the next few days if no objections or bugs arise.
Notably not included is any fix for the mysterious EXT4 file-system corruption on 4.19. That issue is still being investigated and looking like it could be a problem in the kernel outside of the EXT4 code itself but still not entirely clear. Also not included for Linux 4.19.7 is any fix for the Radeon RX 590 Linux support. While that card is now lighting up with the latest testing patches, there is now a load issue being explored causing hangs under OpenGL/Vulkan loads.