This is nothing short of legendary. Was following the thread on Twitter and LOLed at the replies of “Praise be Jart”, but there’s something of the sublime here. Great weight wrangling judo :)
The peculiarity here is that tools like htop were reporting the improvement as being an 8x improvement, which is interesting, because RAM use is only 2x better due to my change. The rusage.com page fault reporting was also interesting too. This is not due to sparseness. It's because htop was subtracting MAP_SHARED memory. The htop docs say on my computer that the color purple is used to display shared memory, and yellow is used to display kernel file caches. But it turned out it just uses yellow for both, even though it shouldn't, because mincore() reported that the shared memory had been loaded into the resident set size.