Re: Possible regression with cgroups in 3.11

[Bjorn Helgaas <bhelgaas@google.com>]

On Mon, Nov 18, 2013 at 11:29:32AM -0800, Yinghai Lu wrote:
> On Mon, Nov 18, 2013 at 10:14 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> >> A bit of comment here would be nice but yeah I think this should work.
> >> Can you please also queue the revert of c2fda509667b ("workqueue:
> >> allow work_on_cpu() to be called recursively") after this patch?
> >> Please feel free to add my acked-by.
> >
> > OK, below are the two patches (Alex's fix + the revert) I propose to
> > merge.  Unless there are objections, I'll ask Linus to pull these
> > before v3.13-rc1.
> >
> >
> >
> > commit 84f23f99b507c2c9247f47d3db0f71a3fd65e3a3
> > Author: Alexander Duyck <alexander.h.duyck@intel.com>
> > Date:   Mon Nov 18 10:59:59 2013 -0700
> >
> >     PCI: Avoid unnecessary CPU switch when calling driver .probe() method
> >
> >     If we are already on a CPU local to the device, call the driver .probe()
> >     method directly without using work_on_cpu().
> >
> >     This is a workaround for a lockdep warning in the following scenario:
> >
> >       pci_call_probe
> >         work_on_cpu(cpu, local_pci_probe, ...)
> >           driver .probe
> >             pci_enable_sriov
> >               ...
> >                 pci_bus_add_device
> >                   ...
> >                     pci_call_probe
> >                       work_on_cpu(cpu, local_pci_probe, ...)
> >
> >     It would be better to fix PCI so we don't call VF driver .probe() methods
> >     from inside a PF driver .probe() method, but that's a bigger project.
> >
> >     [bhelgaas: disable preemption, open bugzilla, rework comments & changelog]
> >     Link: https://bugzilla.kernel.org/show_bug.cgi?id=65071
> >     Link: http://lkml.kernel.org/r/CAE9FiQXYQEAZ=0sG6+2OdffBqfLS9MpoN1xviRR9aDbxPxcKxQ@mail.gmail.com
> >     Link: http://lkml.kernel.org/r/20130624195942.40795.27292.stgit@ahduyck-cp1.jf.intel.com
> >     Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> >     Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> >     Acked-by: Tejun Heo <tj@kernel.org>
> 
> Tested-by: Yinghai Lu <yinghai@kernel.org>
> Acked-by: Yinghai Lu <yinghai@kernel.org>

Thanks, I added these and pushed my for-linus branch for -next to
pick up before I ask Linus to pull them.

Bjorn