RE: [PATCH] ia64 add idle loop entry/exit notifier

["Chen, Kenneth W" <kenneth.w.chen@intel.com>]

Stephane Eranian wrote on Wednesday, November 15, 2006 2:24 PM
> Here is a patch which adds an idle notifier to IA-64. It clones
> the one in X86-64. You can register a callback via the notifier
> and you get called when:
> 	- entering the lowest level of the idle loop
> 	- exiting the lowest level of the idle loop, either normally
> 	  or to process an interrupt
> 
> Basically, you can monitor useful vs. useless work accomplished
> by the idle thread on each processor.

Is idle notifier a light weight callback thingy?  I happen to work
on an application environment that cycles CPUs into gazillion nano
second sleep due to tons of sleep / wake up activity from thousands
of processes. I'm just checking and hope this notifier chain isn't
going to add significant overhead when cycling through busy/idle.


- Ken