On 29-Aug-22 8:10 PM, Peter Zijlstra wrote:

On Mon, Aug 29, 2022 at 02:04:33PM +0200, Peter Zijlstra wrote:

quoted

On Mon, Aug 29, 2022 at 05:03:47PM +0530, Ravi Bangoria wrote:

quoted

@@ -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.

Not sure I follow. Can you please elaborate.

Thanks,
Ravi