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Make Linux fast again

Posted: Fri May 17, 2019 5:11 am
by bluebell
https://make-linux-fast-again.com/

noibrs noibpb nopti nospectre_v2 nospectre_v1 l1tf=off nospec_store_bypass_disable no_stf_barrier mds=off mitigations=off

Let's test.

Re: Make Linux fast again

Posted: Fri May 17, 2019 5:21 am
by khz
:-D

Re: Make Linux fast again

Posted: Fri May 17, 2019 6:56 pm
by jonetsu
I think China will oppose.

Re: Make Linux fast again

Posted: Fri May 17, 2019 7:48 pm
by tavasti
Fast but not safe. For computer which is not connected to network ever, that might be ok option.

Re: Make Linux fast again

Posted: Fri May 17, 2019 7:55 pm
by bluebell
tavasti wrote:Fast but not safe. For computer which is not connected to network ever, that might be ok option.


I'd say for a single user workstation you're still safer than with any Windows system.

Most exploits affect people who have different customers on the same machine and have to keep their address spaces and registers separated.

Re: Make Linux fast again

Posted: Fri May 17, 2019 7:58 pm
by bluebell
jonetsu wrote:I think China will oppose.


Intel might oppose. All those fixes make machines slower so people have to buy faster CPUs or CPUs with more cores. Is there something better in the world of capitalism than having others pay for own failures?

Re: Make Linux fast again

Posted: Fri May 17, 2019 8:59 pm
by merlyn
It would be interesting to see if disabling mitigations results in improved audio performance. I would try it, but I've got an AMD chip. :) I've read it doesn't make much difference on AMD. Although I probably will find out for myself. This was useful :

Code: Select all

★ grep . /sys/devices/system/cpu/vulnerabilities/*
/sys/devices/system/cpu/vulnerabilities/l1tf:Not affected
/sys/devices/system/cpu/vulnerabilities/meltdown:Not affected
/sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Not affected
/sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user pointer sanitization
/sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Full AMD retpoline, STIBP: disabled, RSB filling

Re: Make Linux fast again

Posted: Sat May 18, 2019 12:14 am
by Death
I don't know what those commands do so I'm scared to try :shock:

Re: Make Linux fast again

Posted: Sat May 18, 2019 12:23 am
by merlyn
It's just one command and the rest is the output. It shows what vulnerabilities a processor has and what the mitigation is. This is back in the news with the discovery of ZombieLoad :) which doesn't show up in that list yet.

Re: Make Linux fast again

Posted: Sat May 18, 2019 12:46 am
by Death
merlyn wrote:It's just one command and the rest is the output. It shows what vulnerabilities a processor has and what the mitigation is. This is back in the news with the discovery of ZombieLoad :) which doesn't show up in that list yet.


Oh I meant the command in the first post :P

Re: Make Linux fast again

Posted: Sat May 18, 2019 1:09 am
by merlyn
I see. @bluebell posted a list of kernel boot options. They turn off all mitigations against spectre, meltdown and the new one : mds.

Re: Make Linux fast again

Posted: Sat May 18, 2019 1:31 am
by Death
Ah yeh I get it now after looking up and running the command you ran. I appear to be ok with my system. Not gonna try disabling those mitigations though haha :wink:

Re: Make Linux fast again

Posted: Sat May 18, 2019 4:05 am
by Michael Willis
Death wrote:Not gonna try disabling those mitigations though haha :wink:

This is definitely "here be dragons" territory.

Re: Make Linux fast again

Posted: Sat May 18, 2019 12:20 pm
by Death
Yes. I thought it was dodgy just running the latest Mesa Devel drivers for a while haha :lol:

Re: Make Linux fast again

Posted: Sat May 18, 2019 12:44 pm
by merlyn
Death wrote:I thought it was dodgy just running the latest Mesa Devel drivers

In terms of having a stable, reliable system development drivers are more of a risk than disabling meltdown/spectre mitigations.

I read that Intel wanted the mitigations to be 'opt-in'. The Linux kernel would be distributed without the performance hit to Intel hardware, and if you were a government employee, a spy, an international businessman or other party with valuable secrets the mitigations could be enabled.

It was Linus who insisted the mitigations be 'opt-out'.