It seems that the realtime folks are fuzzy on what they are trying to accomplish. I thought realtime was ensuring that the kernel always responds in a mininum time interval to an event but I dont see any discussion of what the minimum time interval is.
From the article it seems that there are numerous features in the kernel that are currently not "Realtime". That probably means that the potential latencies are beyond any assumable time interval. This includes such basic things as locking.
What is meant by "Realtime" then? What set of functionality of the kernel can be used so that a response is guaranteed within the time interval?