Re: VM fixes [4/4]

[Andrea Arcangeli <andrea@suse.de>]

On Fri, Dec 24, 2004 at 04:06:05PM -0800, Mitchell Blank Jr wrote:
> Andrea Arcangeli wrote:
> > > Again, older Alpha's do not.
> > 
> > If those old cpus really supported smp in linux,
> 
> The question isn't whether those CPUs support SMP; the question is whether
> it's possible to build a kernel that supports both SMP boxes and older
> CPUs.

If you want to support those, you must as well tell gcc with a special
flag to never do byte access. I doubt it'd be a good idea to ship a
single kernel that runs on both those ancient cpus and on the more
recent ones too.

The race was mostly theoretical even for alpha, the current PF_MEMDIE
race in mainline triggering in all x86 and all other actual
architectures, is more likely to trigger infact and it has a huge
priority compared to the alpha ev4 SMP race.

But I'm going to fix the ev4 SMP alpha cpus soon by following Linus's
suggestion to reuse the bitflag arrays we already allocated for similar
stuff.