Re: [PATCH RFC] hotplug-memory: refactor online_pages to separatezone growth from page onlining

[KAMEZAWA Hiroyuki]

On Wed, 02 Apr 2008 15:13:05 -0700
Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
> > Yeah, but I'm just talking about hotplugged memory.  When we add it, we
> > don't have to map the added pages (since they're highmem) and don't have
> > to touch their contents and zero them out, either.  Then, the balloon
> > driver can notice that the memory is too large, and start to balloon it
> > down.
> >   
> 
> I didn't think x86-64 had a notion of highmem.
> 
> How do you prevent the pages from being used before they're ballooned out?
> 

As I mentioned before, you can do that by plug online_page().

Now, online_page() is per-architecture. So, it's not so bad to make this
online_page() to be just a callback.
=
int online_page(struct page *page)
{
	if (online_page_callback)
		return (*online_page_callback)(struct page *page);
	retrun arch_default_online_page(page);
}
=
maybe not so dirty look. 

your ballon driver can overwrite this callback pointer.

Thanks,
-Kame

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/