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Re: Call function on all processors
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Re: Call function on all processors


  • Subject: Re: Call function on all processors
  • From: Michael Smith <email@hidden>
  • Date: Fri, 17 Nov 2006 10:30:40 -0800

Paul Ripke wrote:
How would you call a function on all cpus from a kernel extension?
I'm curious; why would you want to do this?

The only reasons I can think of have to do with changing per-CPU (vs. per context) state, and the OS owns all of that state.

For one, I'm guessing this is the mechanism that CHUD tools uses to get the performance counters out of all the CPUs. But I could be wrong.

I suppose any other per-CPU state would be fair game - SpeedStep
state, thermal state... I can see why some of that might be
interesting.
Most of it is exposed via other interfaces, or not practical to obtain without racing. The very act of trying to read the SpeedStep state can cause it to change, for example...

= Mike

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References: 
 >Call function on all processors (From: Paul Litvak <email@hidden>)
 >Re: Call function on all processors (From: Michael Smith <email@hidden>)
 >Re: Call function on all processors (From: Paul Ripke <email@hidden>)

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