Re: Mysterious CFQ crash and RCU

Paul E. McKenney
2011-05-22T20:13:13Z

On Sun, May 22, 2011 at 09:30:57PM +0200, Paul Bolle wrote:
> On Sat, 2011-05-21 at 16:54 -0700, Paul E. McKenney wrote:
> > On Sun, May 22, 2011 at 12:23:50AM +0200, Paul Bolle wrote:
> > > Is anyone able to spot one or more commits in v2.6.39-rc7..v2.6.39 that
> > > might have fixed this Oops? Or did my chance of hitting this Oops,
> > > somehow, just got a lot smaller in v.2.6.39?
>
> As I just discovered, Fedora Rawhide ships release candidates configured
> with a lot more debugging options set than it ships final releases. So,
> sadly, this didn't get fixed in v2.6.39. It just didn't show up because
> one or more configuration options weren't set while they used to be set
> in the preceding release candidates kernels.
>
> > 5f45c69589b7d ("read_lock() does not always imply rcu_read_lock()") might
> > well be a fix.
>
> It doesn't really matter anymore, but that one was actually already
> included in v2.6.39-rc5.

OK, so maybe time to try out the debug approaches I called out earlier?

Thanx, Paul