Re: [PATCH] VM routine fixes

[Christoph Hellwig <hch@infradead.org>]

On Tue, Nov 09, 2004 at 01:53:06PM +0000, David Howells wrote:
> 
> > Please don't stick CONFIG_MMU all over the place but keep them in as small
> > as possible blocks.
> 
> You seem to have changed your mind. Last I heard from you wanted them in as
> few large blocks as possible. Now you want them in many small blocks. If you
> want it changing, please feel free to supply me with a patch.

sorry, typo.  Should have read as large as possible - small doesn't make
sense with the first half of the sentence anyway.

> > As I told you before please move registration of MMU-only sysctls
> > to a MMU-only file in mm/
> 
> No. These belong in the vm_table. It doesn't seem especially straightforward
> to do what you want. If you want it doing your way, then feel free to send
> Andrew a patch.

It is.  You can register multiple tables for the same hierachy.

> > this is nasty.  The right thing would probably to swich !MMU arches
> > to use the compount-page mechanism from the hugetlb code for this.
> 
> Supply me with a patch and I'll test it. I don't know how the compound-page
> stuff works, but it's quite possibly the wrong way to do it. There is no MMU
> available, so you can't generate adjacency that way.

so look at the code.  It's not about the MMU at all, it's about handling
the Linux page structures.   What you're doing is a big mess and should
not be merged.  So if you want to fix the issue do it properly.