Re: [PATCH 2/4] mm: introduce new VM_NOZEROPAGE flag

Dominik Dingel
2014-10-18T14:49:28Z

On Fri, 17 Oct 2014 15:04:21 -0700
Dave Hansen <dave.hansen@intel.com> wrote:

> Is there ever a time where the VMAs under an mm have mixed VM_NOZEROPAGE
> status? Reading the patches, it _looks_ like it might be an all or
> nothing thing.

Currently it is an all or nothing thing, but for a future change we might want to just
tag the guest memory instead of the complete user address space.

> Full disclosure: I've got an x86-specific feature I want to steal a flag
> for. Maybe we should just define another VM_ARCH bit.
>

So you think of something like:

#if defined(CONFIG_S390)
# define VM_NOZEROPAGE VM_ARCH_1
#endif

#ifndef VM_NOZEROPAGE
# define VM_NOZEROPAGE VM_NONE
#endif

right?