Subject: Re: [PATCH] powerpc/8xx: fix regression introduced by cache coherency rewrite

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 29 Sep 2009 17:07:11 +1000

On Mon, 2009-09-28 at 18:21 -0700, Rex Feany wrote:
> > It's going to be hard for me to get that "right" since I don't really
> > know what's going on with the core here, but I suppose if we get it
> > moving along with extra tlb invalidations, that should be "good enough"
> > until somebody who really knows what's going on comes up with possibly
> > a better fix.
> 
> I've tried sticking tlbil_va() in those places, nothing seems to help.
> In some cases userspace is slow, in other cases userspace is faster and
> unstable: sometimes commands hang, sometimes I am able to ctrl-c and
> and kill it, sometimes I get other strange crashes or falures (so far no
> kernel oopses though).

And you are positive that with 2.6.31 and your other patch, it works
both fast and stable ? This is strange... the code should be mostly
identical. I'll have a second look and see if I can get you a patch that
reproduce -exactly- the behaviour of 2.6.31 plus your patch.

Cheers,
Ben.