Re: [PATCH 1/2] mm: use is_migrate_highatomic() to simplify the code

[Michal Hocko]

On Mon 06-03-17 12:43:18, Andrew Morton wrote:
> On Mon, 6 Mar 2017 14:38:33 +0100 Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> 
> > On Fri 03-03-17 15:06:19, Andrew Morton wrote:
> > > On Fri, 3 Mar 2017 14:18:08 +0100 Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> > > 
> > > > On Fri 03-03-17 19:10:13, Xishi Qiu wrote:
> > > > > Introduce two helpers, is_migrate_highatomic() and is_migrate_highatomic_page().
> > > > > Simplify the code, no functional changes.
> > > > 
> > > > static inline helpers would be nicer than macros
> > > 
> > > Always.
> > > 
> > > We made a big dependency mess in mmzone.h.  internal.h works.
> > 
> > Just too bad we have three different header files for
> > is_migrate_isolate{_page} - include/linux/page-isolation.h
> > is_migrate_cma{_page} - include/linux/mmzone.h
> > is_migrate_highatomic{_page} - mm/internal.h
> > 
> > I guess we want all of them in internal.h?
> 
> I suppose so.  arch/powerpc/mm/mmu_context_iommu.c is using
> is_migrate_cma_page which would need some attention.  

Ble. I am really wondering whether these helpers actually make the end
result really worth all the troubles and the mess.

-- 
Michal Hocko
SUSE Labs