Re: PATCH powerpc Merge asm-ppc*/rwsem.h

Jon Loeliger [off-list ref] wrote:

No problem.  I _can_ resubmit the patch with this fix.
However, I am not certain that I should yet.

I'd suggest that you wait until the merge is complete, I think.

But what do you wan to do with ppc32 land then?
Leaving it a "signed long" will limit ppc32 land but
not ppc64 folks.  (No problem.)

I'd suggest "signed long" in both cases. A maximum of 32K processes on ppc32
is probably reasonable.

Also, this begs the question of the comment from Paul:

    struct rw_semaphore {
	/* XXX this should be able to be an atomic_t  -- paulus */
	signed int		count;

Paul can be wrong sometimes:-)

Changing to atomic_t would leave the 32K process limit in place.

Changing the size of counter will cause bad sizes
due to the actual treatment of count as an atomic_t.

You will not be able to use the standard atomic ops unless you increase them
to 64-bits on ppc64.

And if we _do_ convert it to be an atomic_t, should _that_
be where the real type for count gets established?

You should not do that unless you increase atomic_t to 64-bits on ppc64.

And finally, I've been working on merging header files
under the vague guideline of "merge maintaining existing
functionality/breakage".  I've been trying NOT to introduce
simultaneous "improvements" at the risk of breaking something.

Sounds reasonable.

To that end, I ask if the request to make 'count' be 64-bits
should be submitted as a follow on patch that stands on its
own and can clean up around it as necessary?  Or do you want
it mixed in with this "merge" patch too?

Follow-on is fine.

David