Slashdot Mirror

← Back to Stories (view on slashdot.org)

Linux 4.20 is Running Slower Than 4.19 On Intel CPUs (phoronix.com)

Posted by msmash on from the closer-look dept.

Freshly Exhumed writes: An intentional kernel change in Linux kernel 4.20 for enhanced Spectre mitigation is unfortunately causing Intel Linux performance to be much slower than with 4.19. That change is 'STIBP' (Single Thread Indirect Branch Predictors), which allows for preventing cross-hyperthread control of decisions that are made by indirect branch predictors. It affects Intel systems that have up-to-date microcode and CPU Hyper Threading enabled. Phoronix gives the evidence.

3 of 137 comments (clear)

  1. Re:What is worse... by Anonymous Coward · · Score: 3, Informative

    You *can* have both secure and faster... with AMD.

  2. Re:Solution is simple by Mysticalfruit · · Score: 5, Informative

    Add this to your kernel boot line:

    pti=off spectre_v2=off l1tf=off nospec_store_bypass_disable no_stf_barrier

    --
    Yes Francis, the world has gone crazy.
  3. Re:Disableable? by F.Ultra · · Score: 4, Informative

    You can disable it with a boot flag "spectre_v2=off nopti"