I think that the page isolation slows it down, even if it doesn't completely eliminate it.
The second test had something like a 0.05% success rate on my PC, and took over an hour to get a few dozen values read.
After trying this with the new kernel, I started up an AWS instance and ran the tests there. The first test (KASLR) succeeded within a few seconds, and the second test had a 100% success rate (read 1575 values in a few seconds).