Messages in this thread | | | Date | Wed, 28 Aug 2002 13:46:11 -0700 (PDT) | From | Linus Torvalds <> | Subject | RE: [PATCH][2.5.32] CPU frequency and voltage scaling (0/4) |
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On Wed, 28 Aug 2002, Grover, Andrew wrote: > > Well TMTA CPUs would seem to be easy, because all this is done behind the > OS's back, right?
Yes. However, I certainly wouldn't mind having the same interfaces as everybody else to set things like "aggressive" vs "powersave". Transmeta does all the actual _work_ behind the OS's back, but you can still tell the CPU what policy to take, and what frequency limits to use.
> Let's talk about CPUs in which the OS has to control processor performance. > The way I see it, there are a bunch of inputs that are going to determine > CPU speed & voltage: user preference, workload, and thermals.
Absolutely.
> Any workload analysis has to be in the kernel.
...with user mode input (ie user mode can know a lot of high-level stuff that the kernel _doesn't_ know). So the kernel does potentially need user input on policy.
Linus
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