[xfs-masters] Re: Linux 2.6.17-rc2 - notifier chain problem?

[Ashok Raj <ashok.raj@xxxxxxxxx>]

On Wed, Apr 26, 2006 at 11:43:48AM -0700, Andrew Morton wrote:
> Chandra Seetharaman <sekharan@xxxxxxxxxx> wrote:
> Ashok's the one who has spent most time with this.  Basically _everything_
> to do with register_cpu_notifier() and all the things which call it should
> be __cpuinit and should be tossed away during boot on non-cpu-hotplug
> kernels.
> 
> But there are a few nasty problems with that which made us give up.

I think we got to a reasonable start, until i got busy with other things
and didnt complete it all the way to be ready to submit. There were many files
that got affected, so we thought may be could take smaller steps.

for the above xfs, if you want to avoid the ifdef CONFIG_HOTPLUG_CPU
you could choose to use the hotcpu_notifier() which is null macro when 
CONFIG_HOTPLUG_CPU=n


The problem we ran into was some of the startup code depends on the notifier
call chain for smp bringup, hence we couldn't nuke it similar to 
hotcpu_notifier().

so we ended up calling that function for early risers as 
early_register_cpu_notifier(), and all functions/data with __cpuinit etc to
overcome that issue.

I will try to pursue to again when i get a chance.
-- 
Cheers,
Ashok Raj
- Open Source Technology Center