Language Selection

English French German Italian Portuguese Spanish

Login

Enter your Tux Machines username.
Enter the password that accompanies your username.

More in Tux Machines

today's howtos

Android Leftovers

The Spectre/Meltdown Performance Impact On Linux 4.20, Decimating Benchmarks With New STIBP Overhead

As outlined yesterday, significant slowdowns with the Linux 4.20 kernel turned out to be due to the addition of the kernel-side bits for STIBP (Single Thread Indirect Branch Predictors) for cross-HyperThread Spectre Variant Two mitigation. This has incurred significant performance penalties with the STIBP support in its current state with Linux 4.20 Git and is enabled by default at least for Intel systems with up-to-date microcode. Here are some follow-up benchmarks looking at the performance hit with the Linux 4.20 development kernel as well as the overall Spectre and Meltdown mitigation impact on this latest version of the Linux kernel. Some users have said AMD also needs STIBP, but at least with Linux 4.20 Git and the AMD systems I have tested with their up-to-date BIOS/microcode, that hasn't appeared to be the case. Most of the AMD STIBP references date back to January when Spectre/Meltdown first came to light. We'll see in the week ahead if there is any comment from AMD but at this time seems to be affecting up-to-date Intel systems with the Linux 4.20 kernel. Read more

Today in Techrights