Re: [PATCH] perf: Rewrite core context handling

[Peter Zijlstra]

On Mon, Aug 29, 2022 at 02:04:33PM +0200, Peter Zijlstra wrote:
> On Mon, Aug 29, 2022 at 05:03:47PM +0530, Ravi Bangoria wrote:
> > @@ -12598,6 +12590,7 @@ EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
> >  
> >  void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
> >  {
> > +#if 0 // XXX buggered - cpu hotplug, who cares
> >  	struct perf_event_context *src_ctx;
> >  	struct perf_event_context *dst_ctx;
> >  	struct perf_event *event, *tmp;
> > @@ -12658,6 +12651,7 @@ void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
> >  	}
> >  	mutex_unlock(&dst_ctx->mutex);
> >  	mutex_unlock(&src_ctx->mutex);
> > +#endif
> >  }
> >  EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
> >  
> 
> Note to self; fix this :-) I'll see if I have time for that later today.

Urgh, while going through that it appears the whole refcounting thing
isn't fully done either.