> but what kind of Real World workload or environment would one need to be in to see this in action?

Hmm, Facebook perhaps.

Emedded devices tend to use zswap/zram which [yet] don't support THP, as far as I know. For instance, take a look at zswap_frontswap_store():

         /* THP isn't supported */ 
         if (PageTransHuge(page)) { 
                 ret = -EINVAL; 
                 goto reject; 
         } 

Once zswap [and, perhaps, zram] gain THP swap out/in support, embedded devices [some of which use swap quite heavily] should also see a considerable performance improvement.

P.S. I didn't check the patch set, may be zswap THP support is already in there.

-ss