Messages in this thread | | | Date | Sat, 2 Apr 2011 22:00:21 +0100 | From | Alan Cox <> | Subject | Re: [PATCH 16/18] 2.6.40: x86 idle APM: remove deprecated apm_cpu_idle() |
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> This patch series was posted in reply to a table of contents > > https://lkml.org/lkml/2011/4/2/8 > > "By the end of this series, pm_idle is removed as a public > x86 idle-loop registration mechanism. A few other things are > cleaned up in the process."
Ok so lets rewind a bit - why do we want to remove pm_idle rather than just fix up the way registration occurs. It's just a symbol, one trivial interface that is exported and perhaps wants the export method tidying up.
> Trinabh also replied to you, pointing one of the previous > LKML discussions about the mis-use of pm_idle.
And there are misuses of just about every kernel symbol - kmalloc for example causes some people a lot of trouble !
> We'll create a new APM cpuidle driver in Linux (Trinabh prototyped one), > and at the same time, schedule it for removal in a year. Personally, > I think it is make-work, and in real-life it is more likely to do > more harm than removing apm_idle, but I don't want to stand in the > way of process.
So you could just leave it alone - that's less work, less disruption and doesn't do any harm at all.
As I read this the plan at the moment otherwise is
- churn up all the code - remove PM idle hook - rewrite the APM code - replace the APM code
whereas you could just leave the symbol exported or even just a hook to make people to do it right using:
int register_pm_idle(function);
Simples yes ?
and then wait a year
For that matter instead of writing a new driver you could just stuff APM into same hooks we have for virtualisation !
This whole patch series appears to be a giant piece of pointless makework.
Alan
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