Re: suspend2 merge (was Re: [Suspend2-devel] Re: CFS and suspend2: hang in atomic copy)

Ingo Molnar
2007-04-26T12:16:41Z

* Christoph Hellwig <hch@infradead.org> wrote:

> > The interface isn't even 64/32-bit compatible...
>
> It's not . And it's one of the worst interface I've seen lately. Did
> anyone actually review this crap before it went in? I completely
> agree with Linus that these kind of boundaries that lead to horribly
> complex ioctl interface are totally wrong.

it's a bit hard to see the point of it anyway: the resume binary (much
of the focus of the ioctls) fundamentally lives as an 'initrd binary' -
and most of the stuff that wants to execute in an initrd is
fundamentally tied to the kernel anyway.

Perhaps we should allow "in-kernel userspace" that would be allowed to
grow ad-hoc interfaces and linking that would only be compatible with
the kernel they are embedded into: e.g. the klibc stuff in linux/usr/*
could link to the kernel (via whatever method) and just be in essence
another type of kernel code - but happening to execute in user-space,
having access to the normal user-space facilities and being able to link
to (GPL) user-space libraries. Perhaps this would bridge the "i want to
tinker in user-space because it's technically easier/cleaner there" and
"fine but that needs formalized ABIs for your connection to
kernel-space" gap.

> Now suspend2 wasn't exactly nice either when I last reviewed it, but
> we should probably give it another attempt if we can sort out a proper
> incremental merge.

yeah, it still has quite a bit of work left, but it looked fundamentally
split-uppable.

Ingo