Re: [PATCH] hibernation should work ok with memory hotplug

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 29 Oct 2008 13:25:00 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> On Wednesday, 29 of October 2008, Pavel Machek wrote:
> > 
> > hibernation + memory hotplug was disabled in kconfig because we could
> > not handle hibernation + sparse mem at some point. It seems to work
> > now, so I guess we can enable it.
> 
> OK, if "it seems to work now" means that it has been tested and confirmed to
> work, no objection from me.

yes, that was not a terribly confidence-inspiring commit message.

3947be1969a9ce455ec30f60ef51efb10e4323d1 said "For now, disable memory
hotplug when swsusp is enabled.  There's a lot of churn there right
now.  We'll fix it up properly once it calms down." which is also
rather rubbery.  

Cough up, guys: what was the issue with memory hotplug and swsusp, and
is it indeed now fixed?

Thanks.


> 
> > Signed-off-by: Pavel Machek <pavel@suse.cz>
> > 
> > 
> > diff -ur linux/mm/Kconfig linux.tmp/mm/Kconfig
> > --- linux/mm/Kconfig	2008-10-27 10:10:59.000000000 +0100
> > +++ linux.tmp/mm/Kconfig	2008-10-29 10:02:41.000000000 +0100
> > @@ -128,12 +128,9 @@
> >  config MEMORY_HOTPLUG
> >  	bool "Allow for memory hot-add"
> >  	depends on SPARSEMEM || X86_64_ACPI_NUMA
> > -	depends on HOTPLUG && !HIBERNATION && ARCH_ENABLE_MEMORY_HOTPLUG
> > +	depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
> >  	depends on (IA64 || X86 || PPC64 || SUPERH || S390)
> >  
> > -comment "Memory hotplug is currently incompatible with Software Suspend"
> > -	depends on SPARSEMEM && HOTPLUG && HIBERNATION
> > -
> >  config MEMORY_HOTPLUG_SPARSE
> >  	def_bool y
> >  	depends on SPARSEMEM && MEMORY_HOTPLUG
> > 
>