Re: [PATCHv12 2/4] zbud: add to mm/

[Andrew Morton]

On Wed, 29 May 2013 15:42:36 -0500 Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx> wrote:

> > > > I worry about any code which independently looks at the pageframe
> > > > tables and expects to find page struts there.  One example is probably
> > > > memory_failure() but there are probably others.
> > 
> > ^^ this, please.  It could be kinda fatal.
> 
> I'll look into this.
> 
> The expected behavior is that memory_failure() should handle zbud pages in the
> same way that it handles in-use slub/slab/slob pages and return -EBUSY.

memory_failure() is merely an example of a general problem: code which
reads from the memmap[] array and expects its elements to be of type
`struct page'.  Other examples might be memory hotplugging, memory leak
checkers etc.  I have vague memories of out-of-tree patches
(bigphysarea?) doing this as well.

It's a general problem to which we need a general solution.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/