Spectre/Meltdown Performance Impact Across Eight Linux Distributions

[phoronix]

Phoronix: Spectre/Meltdown Performance Impact Across Eight Linux Distributions

While nearly all Linux distributions have been mitigated against the Spectre and Meltdown CPU vulnerabilities for over one year, the performance ahead associated with these speculative execution vulnerabilities can vary. This is especially more so with the enterprise Linux distributions that are generally shipping on older kernel branches prior to where the initial kernel support was mainlined. With recent kernel releases we've also seen varying optimizations and other changes around the Spectre/Meltdown/L1TF mitigations. So for those wondering about the varying impact, here are some side-by-side benchmarks.

http://www.phoronix.com/vr.php?view=27668

[Guest]

Is there a way to know which protection are currently active in the running kernel?

[CochainComplex]

damn that is astonishing. Imagine every Intel consumer would sue intel for their power bill.

[numacross]

Is there a way to know which protection are currently active in the running kernel?

Yes, either use https://github.com/speed47/spectre-meltdown-checker directly or look into the source to see where it's looking if you're not a fan of running random scripts from the Internet.

[Guest]

Yes, either use https://github.com/speed47/spectre-meltdown-checker directly or look into the source to see where it's looking if you're not a fan of running random scripts from the Internet.

Thanks.

[milkylainen]

Craptastic. I'd be furious if I had to foot the power and node density bill for keeping this shitshow running.
Whatever happened to the Intel class action lawsuits? There were a bunch of them running for the Intel wallet at the beginning of 2018.
Right after Brian Krzanich dumped his stock.

[wagaf]

How to disable Spectre/Meltdown protections on ubuntu:

• edit /etc/default/grub
• Add
  "pti=off spectre_v2=off l1tf=off nospec_store_bypass_disable no_stf_barrier"
  to GRUB_CMDLINE_LINUX_DEFAULT
• Run update-grub

[nokipaike]

wow, it's like being back a decade ...

[alex_sh]

I wonder if the slowdown is this bad with the latest Intel CPUs (9900K, for example), which are supposed to have fixes for some (most?) of the Spectre/Meltdown stuff.
Does kernel automatically disable the protections if they're available in hardware?

[r1348]

Yes, either use https://github.com/speed47/spectre-meltdown-checker directly or look into the source to see where it's looking if you're not a fan of running random scripts from the Internet.

Thank you for sharing this, this script is just brilliant.