Re: [patch -mm 4/4] mempolicy: remove includes for duplicate headers

David Rientjes
2008-03-06T20:52:57Z

On Thu, 6 Mar 2008, Paul Jackson wrote:

> > Remove #includes for:
> >
> > linux/mempolicy.h (already from linux/migrate.h)
> > linux/mm.h (already from linux/highmem.h)
>
> I didn't see any problem offhand with the other patches 0 to 3 in this
> set, but this patch 4/4 surprises me.
>
> Perhaps I'm out of phase with what's customary in the kernel, but I
> prefer directly including whatever headers I explicitly need.
> Depending on some other header to drag in something you have explicit
> need of anyway makes things more fragile.
>

It simply decreases the remote chance later that we'll develop obscure
header file dependencies for some archs like we saw with the memcontroller
and the sparc build. There are no strange dependencies that I am
currently aware of, so this is not a bugfix.

The only way this would make things more fragile is if a header file
removes an include for another header file without checking all the users
of the former first and fixing it up in mm/mempolicy.c.