Re: [PATCH] memory hotplug disable boot option

Dave Hansen
2010-06-29T16:03:13Z

On Tue, 2010-06-29 at 11:56 +0900, KOSAKI Motohiro wrote:
> > On Mon, 2010-06-28 at 08:44 -0700, Greg KH wrote:
> > > > The directories being created are the standard directories, one for each of the memory
> > > > sections present at boot. I think the most used files in each of these directories
> > > > is the state and removable file used to do memory hotplug.
> > >
> > > And perhaps we shouldn't really be creating so many directories? Why
> > > not work with the memory hotplug developers to change their interface to
> > > not abuse sysfs in such a manner?
> >
> > Heh, it wasn't abuse until we got this much memory. But, I think this
> > one is pretty much 100% my fault.
> >
> > Nathan, I think the right fix here is probably to untie sysfs from the
> > sections a bit. We should be able to have sysfs dirs that represent
> > more than one contiguous SECTION_SIZE area of memory.
>
> Why do we need abi breakage? Yourself talked about we guess ppc don't
> actually need 16MB section. I think IBM folks have to confirm it.
> If our guessing is correct, the firmware fixing is only necessary.

>From the mouth of the kernel dumbass who coded this up: it's not the
firmware's fault. We shouldn't punt this to them, and the proper fix
_isn't_ in the firmware, plus they may have other more fundamental
reasons to keep the LMB sizes what they are.

-- Dave