Re: [PATCH] build fix for generic debug pagealloc

From: Rafael J. Wysocki
Date: Fri Apr 03 2009 - 16:39:08 EST


On Friday 03 April 2009, Ingo Molnar wrote:
>
> * Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > > +config DEBUG_PAGEALLOC
> > > + bool "Debug page memory allocations"
> > > + depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
> > > + depends on !HIBERNATION || !PPC && !SPARC
> > > + ---help---
> > > + Unmap pages from the kernel linear mapping after free_pages().
> > > + This results in a large slowdown, but helps to find certain types
> > > + of memory corruptions.
> > > +
> >
> > I guess this is why it wasn't discovered in my compile testing.
> > It's quite regrettable that `make allmodconfig' didn't enable the
> > feature. That's what allmodconfig is for.
>
> Hm, i _do_ remember some hibernation magic fix from Rafael, in the
> area of debugalloc. Many months ago.
>
> Rafael, is it supposed to work? If yes, i think we should unblock
> it.

Yes, it is, at least on x86.

ISTR using DEBUG_PAGEALLOC with hibernation quite some time ago already.

Thanks,
Rafael
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