Re: [PATCH 1/2] Export get_user_pages_fast

From: Adrian Bunk
Date: Wed Jul 30 2008 - 13:40:46 EST


On Wed, Jul 30, 2008 at 10:28:17AM -0700, Andrew Morton wrote:
> On Wed, 30 Jul 2008 20:18:45 +0300 Adrian Bunk <bunk@xxxxxxxxxx> wrote:
>
> > > > The export would still only be available on x86 since no other arch
> > > > would define CONFIG_HAVE_GET_USER_PAGES_FAST.
> > > >
> > >
> > > That's presently true in Linus mainline. The powerpc implementation is
> > > in -mm, but apprarently needs a bit more work.
> >
> > I still don't get the advantage of your suggestion.
> >
> > With the powerpc implementation included your suggestion doesn't change
> > the fact that the export is available only on x86 and powerpc, and if a
> > driver author mistakenly uses it and only tests it's driver on x86 it
> > will still break on architectures other than x86 or powerpc.
>
> On non-CONFIG_HAVE_GET_USER_PAGES_FAST architectures a
> get_user_pages_fast() call will in fact call get_user_pages().
>
> On CONFIG_HAVE_GET_USER_PAGES_FAST architectures, get_user_pages_fast()
> is a real function. All architectures which implement that function
> should export it to modules. Hence it should be exported from within
> generic code.

Are we talking at cross purposes?

I thought you were talking an error due to a missing function.

If you think about an error where the function is present but only the
EXPORT_SYMBOL is missing then I get your point (although I do not
consider it a huge problem).

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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