Re: Inquiry: Should we remove "isolcpus= kernel boot option? (may have realtime uses)

[Ingo Oeser]

Hi Max,

On Wednesday 04 June 2008, Max Krasnyanskiy wrote:
> btw Ingo, I just realized that maxcpu= option is exactly what you need.
> Here is how you can use it.
> Boot your system with maxcpus=1. That way the kernel will only bring up 
> processor 0. I'm assuming cpu0 is "good" otherwise your system is totally 
> busted :). Other cpus will stay off-line and will not be initialized.
> Then once the system boots you can selectively bring "good" processors online 
> by doing
> 	echo 1 > /sys/devices/system/cpu/cpuN/online
> 

I just tested it on the Ubuntu Hardy standard kernel on an AMD DualCore.
The /sys/devices/system/cpu/cpu1 entry doesn't show up.

I can send you the dmesg/config in private, if you want.

Did you test your suggestion? 

After our discussion, I tried to find the right spot to implement 
"disablecpus=" myself, but couldn't find the right position to hook it up.

If your idea would work out, I would ACK it. Even in bold :-)


Best Regards

Ingo Oeser
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