Re: Non-GPL export of invalidate_mmap_range

Andrew Morton
2004-02-19T18:56:08Z

Christoph Hellwig <hch@infradead.org> wrote:
>
> On Wed, Feb 18, 2004 at 03:32:34PM -0800, Andrew Morton wrote:
> > > Yes. We've traditionally not exported symbols unless we had an intree user,
> > > and especially not if it's for a module that's not GPL licensed.
> >
> > That's certainly a good rule of thumb and we (and I) have used it before.
> >
> > What is the reasoning behind it?
>
> The reason is that someone who wants to distribute a binary only module
> has to show it's module is not a derived work, and someone who needs new
> core in the kernel and new exports pretty much shows his work is deeply
> integrated with the kernel.

Needing access to invalidate_mmap_range() is surely not an indication of a
derived work. It is an indication of a need for a reliable way to achieve
inter-node cache consistency. Other distributed filesystems will need this
and probably AIX already provides it.