Re: [PATCH] [4/4] SLAB: Fix node add timer race in cache_reap

Nick Piggin
2010-02-15T10:41:42Z

On Mon, Feb 15, 2010 at 11:32:50AM +0100, Andi Kleen wrote:
> On Mon, Feb 15, 2010 at 05:15:35PM +1100, Nick Piggin wrote:
> > On Thu, Feb 11, 2010 at 09:54:04PM +0100, Andi Kleen wrote:
> > >
> > > cache_reap can run before the node is set up and then reference a NULL
> > > l3 list. Check for this explicitely and just continue. The node
> > > will be eventually set up.
> >
> > How, may I ask? cpuup_prepare in the hotplug notifier should always
> > run before start_cpu_timer.
>
> I'm not fully sure, but I have the oops to prove it :)

Hmm, it would be nice to work out why it's happening. If it's completely
reproducible then could I send you a debug patch to test?