Re: [RFC] unify semaphore implementations

Paul Mackerras
2005-04-29T00:44:17Z

Benjamin LaHaise writes:

> Please review the following series of patches for unifying the
> semaphore implementation across all architectures (not posted as
> they're about 350K), as they have only been tested on x86-64. The
> code generated is functionally identical to the earlier i386
> variant, but since gcc has no way of taking condition codes as
> results, there are two additional instructions inserted from the
> use of generic atomic operations. All told the >6000 lines of code
> deleted makes for a much easier job for subsequent patches changing
> semaphore functionality. Cheers,

Vetoed.

You have made semaphores bigger and slower on the architectures that
have load-linked/store-conditional instructions, which is at least
ppc, ppc64, sparc64 and alpha. Did you take the trouble to understand
the ppc semaphore implementation?

What changes do you want to make to the semaphore functionality?

Paul.