My initial support for this patch was based on an artifical load but one I
felt was plausible to trigger if CMA was being used. In a normal workload
I thought it might be possible to hit if a large process exited freeing
a lot of pagetable pages from MIGRATE_UNMOVABLE blocks at the same time
but that is a little unlikely and a test case would also look very artifical.
Hence, I believe that if you require a real workload to demonstrate the
benefit of the patch that it will be very difficult to find. The primary
decision is if CMA needs this or not. I was under the impression that it
was a help for CMA allocation success rates but I may be mistaken.