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

John Kacur
2011-11-14T17:40:04Z

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?

>
> 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