Re: [patch 0/7] [RFC] SLUB: Improve allocpercpu to reduce per cpu access overhead

David Miller
2007-11-01T05:28:06Z

From: Christoph Lameter <clameter@sgi.com>
Date: Wed, 31 Oct 2007 18:21:02 -0700 (PDT)

> On Wed, 31 Oct 2007, David Miller wrote:
>
> > From: Christoph Lameter <clameter@sgi.com>
> > Date: Wed, 31 Oct 2007 18:12:11 -0700 (PDT)
> >
> > > On Wed, 31 Oct 2007, David Miller wrote:
> > >
> > > > All I can do now is bisect and then try to figure out what about the
> > > > guilty change might cause the problem.
> > >
> > > Reverting the 7th patch should avoid using the sparc register that caches
> > > the per cpu area offset? (I though so, does it?)
> >
> > Yes, that's right, %g5 holds the local cpu's per-cpu offset.
>
> And if I add the address of a percpu variable then I get to the variable
> for this cpu right?

Right.

I bisected the crash down to:

[PATCH] newallocpercpu