Subject: Re: linux-next: "hugetlb: hugepage migration core" breaks compilation on s390

From: Heiko Carstens <[email-masked]>
Date: Mon, 11 Oct 2010 16:22:52 +0200

On Mon, Oct 11, 2010 at 04:08:34PM +0200, Andi Kleen wrote:
> On Mon, Oct 11, 2010 at 01:11:31PM +0200, Heiko Carstens wrote:
> > "hugetlb: hugepage migration core" in linux-next breaks compilation on s390:
> > 
> >   CC      mm/migrate.o
> > mm/migrate.c: In function 'remove_migration_pte':
> > mm/migrate.c:143:3: error: implicit declaration of function 'pte_mkhuge'
> > mm/migrate.c:143:7: error: incompatible types when assigning to type 'pte_t' from type 'int'
> > make[1]: *** [mm/migrate.o] Error 1
> > make: *** [mm/migrate.o] Error 2
> > 
> > This is simply because a lot of CONFIG_HUGETLB_PAGE dependent code was added
> > to mm/migration.c which does not depend on that config option. Please fix.
> 
> Most of the functions have inline dummies, just pte_mkhuge() doesn't.
> Anyways the easiest fix would be a simple #ifdef. Does this patch
> work for you?

Yes.

> From: Andi Kleen <[email-masked]>
> Subject: [PATCH] Fix migration.c compilation on s390
> 
> s390 doesn't have huge pages and failed with

s390 has huge pages only in 64 bit mode, but not in 31 bit mode.