drm/amdkfd: Add some eveiction debugging code

Extending the module parameter debug_evictions to also print a stack
trace when the eviction code path is called.

Signed-off-by: Philip Cox <Philip.Cox@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c

@@ -1966,6 +1966,7 @@ int kfd_process_vm_fault(struct device_queue_manager *dqm,
 
 	if (!p)
 		return -EINVAL;
+	WARN(debug_evictions, "Evicting pid %d", p->lead_thread->pid);
 	pdd = kfd_get_process_device_data(dqm->dev, p);
 	if (pdd)
 		ret = dqm->ops.evict_process_queues(dqm, &pdd->qpd);

drivers/gpu/drm/amd/amdkfd/kfd_process.c

@@ -1488,6 +1488,7 @@ void kfd_suspend_all_processes(void)
 	unsigned int temp;
 	int idx = srcu_read_lock(&kfd_processes_srcu);
 
+	WARN(debug_evictions, "Evicting all processes");
 	hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
 		cancel_delayed_work_sync(&p->eviction_work);
 		cancel_delayed_work_sync(&p->restore_work);