Re: [PATCH 2/2] Compile error with allmodconfig and CONFIG_PREEMPT_RT_FULL=y

Paul E. McKenney
2011-11-14T18:01:17Z

On Mon, Nov 14, 2011 at 06:39:47PM +0100, John Kacur wrote:
>
>
> On Mon, 14 Nov 2011, Paul E. McKenney wrote:
>
> > On Mon, Nov 14, 2011 at 02:44:43AM +0100, John Kacur wrote:
> > > ERROR: "in_serving_softirq" [net/sched/cls_cgroup.ko] undefined!
> > >
> > > The above can be fixed by exporting in_serving_softirq
> > >
> > > Signed-off-by: John Kacur <jkacur@redhat.com>
> > >
> > > The above patch was originally for 3.0.9-rt25
> > > But I also needed to cherry-pick it for 3.2-rc1-rt1
> > > ---
> > > kernel/softirq.c | 1 +
> > > 1 files changed, 1 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/kernel/softirq.c b/kernel/softirq.c
> > > index 3db1d6f..5452432 100644
> > > --- a/kernel/softirq.c
> > > +++ b/kernel/softirq.c
> > > @@ -447,6 +447,7 @@ int in_serving_softirq(void)
> > > preempt_enable();
> > > return res;
> > > }
> > > +EXPORT_SYMBOL(in_serving_softirq);
> >
> > Why not EXPORT_SYMBOL_GPL?
>
> I have no problem with that, note however that the upstream file has
>
> EXPORT_SYMBOL(irq_stat);
> EXPORT_SYMBOL(local_bh_disable);
> EXPORT_SYMBOL(_local_bh_enable);
> EXPORT_SYMBOL(local_bh_enable);
> EXPORT_SYMBOL(local_bh_enable_ip);
> EXPORT_SYMBOL(__tasklet_schedule);
> EXPORT_SYMBOL(__tasklet_hi_schedule);
> EXPORT_SYMBOL(__tasklet_hi_schedule_first);
> EXPORT_SYMBOL(tasklet_init);
> EXPORT_SYMBOL(tasklet_kill);
> EXPORT_SYMBOL(__send_remote_softirq);
> EXPORT_SYMBOL(send_remote_softirq);
>
> Any reason we can't change all of those to EXPORT_SYMBOL_GPL?

No idea. But I do suggest making new ones EXPORT_SYMBOL_GPL.

Thanx, Paul

> > With that change,
> >
> > Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> >
> > Not yet ready for mainline, because mainline does not yet have
> > in_serving_softirq(). Therefore not queued for -rcu.
> >
> > Thanx, Paul
> >
> > > /*
> > > * Called with bh and local interrupts disabled. For full RT cpu must
>