Re: [PATCH] sched/core: Export pelt_thermal_tp

[Peter Zijlstra]

On Thu, Oct 28, 2021 at 09:00:56AM -0700, Christoph Hellwig wrote:
> On Thu, Oct 28, 2021 at 12:50:05PM +0100, Qais Yousef wrote:
> > We can't use this tracepoint in modules without having the symbol
> > exported first, fix that.
> 
> Which modules is using this?  In linux-next there does not seems to be
> any user outside of kernel/sched/pelt.c.
> 
> > @@ -36,6 +36,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_rt_tp);
> >  EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_dl_tp);
> >  EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp);
> >  EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_se_tp);
> > +EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_thermal_tp);
> >  EXPORT_TRACEPOINT_SYMBOL_GPL(sched_cpu_capacity_tp);
> >  EXPORT_TRACEPOINT_SYMBOL_GPL(sched_overutilized_tp);
> >  EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_cfs_tp);
> 
> ... and while we're at it, all these exports are unused and should
> be deleted as well.

This is my concession wrt tracepoints. Actual tracepoints are ABI,
exports are in-kernel interfaces and are explicitly not ABI.

This way people can use an external module to get at the tracepoint data
without having in-tree tracepoints.