Re: [PATCH 03/14] mm: Share the anon_vma ref counts between KSM andpage migration

[Rik van Riel]

On 04/06/2010 08:05 PM, Andrew Morton wrote:
> On Fri,  2 Apr 2010 17:02:37 +0100
> Mel Gorman<mel@xxxxxxxxx>  wrote:

> > +#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION)
> > +
> > +	/*
> > +	 * The external_refcount is taken by either KSM or page migration
> > +	 * to take a reference to an anon_vma when there is no
> > +	 * guarantee that the vma of page tables will exist for
> > +	 * the duration of the operation. A caller that takes
> > +	 * the reference is responsible for clearing up the
> > +	 * anon_vma if they are the last user on release
> > +	 */
> > +	atomic_t external_refcount;
> >   #endif
>
> hah.

> > +	anonvma_external_refcount_init(anon_vma);
>
> What a mouthful.  Can we do s/external_//g?

For the function, sure.

However, I believe it would be good to keep the variable
inside the anon_vma as "external_refcount", because the
VMAs attached to the anon_vma take a reference by being
on the list (and leave the refcount alone).
--
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/