Re: cmpxchg() in kernel/workqueue.c breaks things

[Al Viro <viro@ftp.linux.org.uk>]

On Thu, Dec 07, 2006 at 12:09:50AM -0800, David Miller wrote:
> 
> David, you have to fix the locking scheme used in kernel/workqueue.c,
> you absolutely cannot assume that cmpxchg() is available on all
> platforms.  This breaks the build on the platforms that don't
> have such an instruction, and no it cannot emulated.
> 
> Also, because Alan Cox's machine (zeniv) went down, a few folks such
> as Al Viro (CC:'d) had no opportunity to comment on your changes
> before they went in.  This mess would have been avoided if Al had a
> chance to read over this, in particular since he does cross sparc32
> builds he knows that cmpxchg is not available there.

FWIW, the *real* problem with that (and several other recent breakage
incidents) would be avoided if massive cross-arch patchsets would be
posted to linux-arch first.

It wouldn't catch all crap, but at least it would get folks to check
if the damn thing builds.