Re: [PATCH V5 2/2] tracing, perf : add cpu hotplug trace events

[Thomas Gleixner]

On Thu, 24 Feb 2011, Alan Cox wrote:

> > Anybody who is interested in the latency of cpu hotplug is deluding
> > himself, also cpu hotplug is _NOT_ a power management feature, so the
> > rest of your justification just disappeared as well.
> 
> Actually CPU hotplug is a power management feature on some devices where
> you need to shutdown one of the cores to enter low power modes.

Right.

> Remember we use it as part of the suspend paths and various processors
> nowdays drop into a suspend to RAM type state on CPU idling.

The suspend path is using it, but the cpu idle one is hardly using the
hotplug muck.

Thanks,

	tglx
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