[openSUSE] disable Spectre mitigation for performance

[Phoronix] OpenSUSE's Spectre Mitigation Approach Is One Of The Reasons For Its Slower Performance

Check your hardware with this spectre-meltdown-checker(YMMV):
https://github.com/speed47/spectre-meltdown-checker

Passing these parameters to kernel to disable those fixes:
noibrs noibpb nopti nospectre_v2 nospectre_v1


For what's Spectre, go for Chandler Carruth's 2018-CPPCON talk: “Spectre: Secrets, Side-Channels, Sandboxes, and Security”
http://vsdmars.blogspot.com/2018/10/ccppcon-2018-chandler-carruth-spectre_5.html


Reference:
[opensuse-factory] Huge single-core performance loss with spectre v2 mitigation enabled (it's the default)

kernel-parameters.txt

The kernel’s command-line parameters