Re: CX > 1 support for Athlon SMP systems

[Johnathan Hicks <thetech-Pn2JTpibVOrk1uMJSBkQmQ@public.gmane.org>]

Carl Thompson wrote:
> Wow.  This actually seems to work on my Sony laptops.  But I wonder if 
> it is really puting the CPU in C2 because there is no additional power 
> savings or temperature reduction than using ACPI.  Is there any way to 
> test if CPU is going in C2 state? 

I can't think of anything at the hardware level, but you do a printk or 
something inside the while loop that contains the inb() in the idle loop.

> At any rate, since the power savings is comparable to ACPI and the 
> only reason I was using ACPI on these laptops was for the power 
> savings, I have switched to using lvcool + APM instead of ACPI.  
> Battery life seems about the same, and it eliminates the issues I was 
> having with ACPI (CPU usage reading battery status, dropped 
> characters, USB weirdness, undocumented inteface, etc). 

ACPI will likely be fixed eventually... ;-)

> BTW, APM uses about 1/50th to 1/100th the processor time reading 
> battery status on my laptop compared to using ACPI.  No joke. 

Yikes! That's no good, when under CPU load anyway...

--John




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