Proposal for a userspace "architecture portability" library

[Kevin P. Fleming]

Paul Mackerras wrote:

> No, for semaphores and rwsems I was going to use futexes.  Or maybe we
> don't need the kernel's semaphores, rwsems and spinlocks in userspace
> at all.  I'm open to suggestions.

I think that _all_ of these items can find use in userspace, if they are 
usable with glibc's threading implementation and the other userspace 
issues that would be involved.

I for one would love to be able to use lightweight rwsems and spinlocks 
in an application I'm working on, but it's entirely userspace and it 
would be impossible for _me_ to pick out this code from the kernel tree 
and make it work on any architecture that I don't have here (which is 
all of them except x86 <G>).