Re: [PATCH] lockdep fix incorrect percpu usage

Peter Zijlstra
2010-03-30T14:25:19Z

On Tue, 2010-03-30 at 09:45 -0400, Mathieu Desnoyers wrote:
> * Peter Zijlstra (peterz@infradead.org) wrote:
> > On Mon, 2010-03-29 at 23:34 -0400, Mathieu Desnoyers wrote:
> > > Should use per_cpu_ptr() to obfuscate the per cpu pointers (RELOC_HIDE is needed
> > > for per cpu pointers).
> > >
> > > git blame points to commit:
> > >
> > > lockdep.c: commit 8e18257d29238311e82085152741f0c3aa18b74d
> > >
> > > But it's really just moving the code around. But it's enough to say that the
> > > problems appeared before Jul 19 01:48:54 2007, which brings us back to 2.6.23.
> > >
> > > So it should be applied to stable 2.6.23.x to 2.6.33.x (or whichever of these
> > > stable branches are still maintained) and to mainline 2.6.34-rc2.
> >
> > well, definately not to mainline, since that code is utterly busted in
> > mainline due to recent per-cpu changes.
>
> How recent ? I'm based on
>
> commit f57d4e859a8acd63f878cd0534ec4b990b1710dc
> Merge: 0528faa... eed6351...
> Author: Ingo Molnar <mingo@elte.hu>
> Date: Mon Mar 29 18:56:00 2010 +0200
>
> from -tip and I see the problem there, both in module.c and lockdep.c.

Yeah, its basically been busted since the early merge window period,
hopefully Tejun's patches will make it in soon: