Re: KS/Plumbers: c-state governor BOF

[Youquan Song <youquan.song@linux.intel.com>]

> After talking about my RFC patches to the c-state governor with
> Matthew and Arjan, it is clear that the whole concept of how
> things are done could use some more discussion.
>
> Since a good number of us will be in San Diego next week, at
> Kernel Summit / Plumbers / etc, I will organize a c-state
> governor BOF for those who are interested.
>
> Things to think about:
> - what should the c-state governor do?
> - how to best predict the future?
> - what kinds of odd workloads do we need to accomodate?

Hi Rik,

Just notice there is a topic to discuss menu governor at Kernel Summit.
Acutally, I have posted a patchset to at May 11 2012 to bring up the
topic, at that time, I only have a convinced and proved application 
turbostat v1 to prove that my patch are useful. I try to find other
workloads to prove that the patchset are also solidated useful. But I
stucked in other high priority tasks, so I move slow on it.
>From you bring up the issue I guess that you already has real workload
to show this issue. 
My patchset is not only improve repeat mode failure but also improve 
general prediction failure. Let's have a discuss and talk about it.

Here is the patchset posted at May 11 2012.

http://lwn.net/Articles/496919/ "x86,idle: Enhance cpuidle prediction to
handle its failure"
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/02267.html
"[PATCH 1/3] x86,idle: Quickly notice prediction failure for repeat mode"
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/02268.html
"[PATCH 2/3] x86,idle: Quickly notice prediction failure in general case"
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/02269.html
"[PATCH 3/3] x86,idle: Set residency to 0 if target Cstate not really
enter"

Thanks
-Youquan