diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 219722df68d6..e21e1c237301 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1347,6 +1347,9 @@ again:
 		goto enable_and_dump;
 
 	if (tried_times >= pci_try_num) {
+		if (pci_realloc_enable == undefined)
+			printk(KERN_INFO "Some PCI device resources are unassigned, try booting with pci=realloc\n");
+
 		free_list(&fail_head);
 		goto enable_and_dump;
 	}