Re: [linux-pm] [PATCH] cpuidle: avoid singing capacitors

[Andi Kleen <andi@firstfloor.org>]

On Wed, Mar 05, 2008 at 07:04:54AM +0100, Pierre Ossman wrote:
> I still don't follow. Perhaps you can express it in pseudo code? If I have a stale value that I cannot refresh, knowing that it is stale doesn't change anything.

Start: You discovered at some point where you currently have code a variable 
is not updated yet.
Fact: You have some new code that runs before that point
Information: The variable is updated later eventually in the idle exit path.
Fact II: You require the variable to be updated in your new code
Possible solutions: 
(1) you move your new code in a point of the idle exit path after the variable 
is updated 
(2) you move the code that updates the variable earlier before your code
Solution: I described the first variant which is likely easier.
How: I told you where it is updated, so that shouldn't be too difficult. 
Action: Implement solution (1) or (2) 
Action: Test if it works
Check: If test succeeded exit 
Otherwise: Restart at Start

-Andi