On Tue, Mar 01, 2016 at 12:59:07PM +1100, Michael Ellerman wrote:
> On Tue, 2016-09-02 at 03:32:42 UTC, David Gibson wrote:
> > This makes a number of cleanups to handling of mapping failures during
> > memory hotplug on Power:
> >
> > For errors creating the linear mapping for the hot-added region:
> > * This is now reported with EFAULT which is more appropriate than the
> > previous EINVAL (the failure is unlikely to be related to the
> > function's parameters)
> > * An error in this path now prints a warning message, rather than just
> > silently failing to add the extra memory.
> > * Previously a failure here could result in the region being partially
> > mapped. We now clean up any partial mapping before failing.
> >
> > For errors creating the vmemmap for the hot-added region:
> > * This is now reported with EFAULT instead of causing a BUG() - this
> > could happen for external reason (e.g. full hash table) so it's better
> > to handle this non-fatally
> > * An error message is also printed, so the failure won't be silent
> > * As above a failure could cause a partially mapped region, we now
> > clean this up.
> >
> ...
> > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
> > index baa1a23..fbc9448 100644
> > --- a/arch/powerpc/mm/init_64.c
> > +++ b/arch/powerpc/mm/init_64.c
> > @@ -217,15 +219,20 @@ static void vmemmap_remove_mapping(unsigned long
> > start,
> > }
> > #endif
> > #else /* CONFIG_PPC_BOOK3E */
> > -static void __meminit vmemmap_create_mapping(unsigned long start,
> > - unsigned long page_size,
> > - unsigned long phys)
> > +static int __meminit vmemmap_create_mapping(unsigned long start,
> > + unsigned long page_size,
> > + unsigned long phys)
> > {
> > - int mapped = htab_bolt_mapping(start, start + page_size, phys,
> > - pgprot_val(PAGE_KERNEL),
> > - mmu_vmemmap_psize,
> > - mmu_kernel_ssize);
> > - BUG_ON(mapped < 0);
> > + int rc = htab_bolt_mapping(start, start + page_size, phys,
> > + pgprot_val(PAGE_KERNEL),
> > + mmu_vmemmap_psize, mmu_kernel_ssize);
> > + if (rc < 0) {
> > + int rc2 = htab_remove_mapping(start, start + page_size,
> > + mmu_vmemmap_psize,
> > + mmu_kernel_ssize);
>
> This breaks the build when CONFIG_MEMORY_HOTPLUG=n, because
> htab_remove_mapping() is not defined.
>
> The obvious fix of moving htab_remove_mapping() out of CONFIG_MEMORY_HOTPLUG
> works, so I'll do that unless anyone objects.
Sounds good, thanks for the catch.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature
