Re: [PATCH] memory hotplug disable boot option

Greg KH
2010-07-01T23:30:19Z

On Thu, Jul 01, 2010 at 09:31:30AM +0900, KAMEZAWA Hiroyuki wrote:
> On Wed, 30 Jun 2010 08:47:55 -0700
> Greg KH <gregkh@suse.de> wrote:
> > > and adding a scalable interface for large scale machines ?
> > > I'd like to consider something..
> >
> > Dynamically changing the layout on big memory boxes makes sense to me,
> > how about you?
> >
>
> like this ?
> ==
> boot option:
> memory_sysfs_layout=compact
> memory_sysfs_layout=auto (default)
> memory_sysfs_layout=full
>
> Considering briefly, how about this compact layout ?
>
> /sys/devices/system/memory/:
> list, hide, show, memoryX...
>
> list: // show available memory index list.
> #cat list
> 0 1 2 ....10000...
>
> show: //an interface to enable the interface.
> #echo INDEX > memory_index
> will create memoryINDEX diretory.
>
> hide: //an interface to hide the interface.
> #echo INDEX > memory_hide
> will remove memoryINDEX sysfs directory.

Ick, that can get confusing very quickly, and not really solve any of
your root problems, right?

> In compact mode, all memoryX interface are hidden at boot.
> In full mode, all memoryX interaface are shown.
> The Boot option just affects status at boot. If users want, he can make
> all memory sysfs in shown state.
>
> At hot-add event (via acpi) or probe-event, newly created memory section
> should be start from "shown" mode. hotplug scirpt can hide it after online.
>
> At hot-remove, the users has to offline memory before hotplug. He'll has
> to do check list and show interface.
>
> I think this change is not very difficult technically but can this kind of
> interface be allowed ?

Not really, I don't like it.

Why not just simplify what you currently have to not use so many
directories and files?

And maybe, this doesn't belong in sysfs at all...

thanks,

greg k-h