In these scenarios, multipath processing efficiency is very low: 1) There are many paths in multipath devices, 2) Add/delete devices when iSCSI login/logout or FC link up/down. Multipath process so slowly that it is not satisfied some applications, For example, openstack is often timeout in waiting for the creation of multipath devices. The reason of the low processing efficiency I think is that multipath process uevent message one by one, and each one also produce a new dm addition/change/deletion uevent message to increased system resource consumption, actually most of these uevent message have no sense at all. So, can we find out a way to reduce these uevent messages to promote multipath processing efficiency? Personally, I think we can merge these uevent messages before processing. For example, during the 4 iSCSI session login procedures, we can wait for a moment until the addition uevent messages of 4 paths are all arrived, and then we can merge these uevent messages to one and deal with it at once. The way to deal with deletion uevent messages is the same. How do you think about? Any points of view are welcome.