Re: [PATCH] lockdep fix incorrect percpu usage

Mathieu Desnoyers
2010-03-30T13:46:00Z

* 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.

Thanks,

Mathieu

--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.