That's the fascinating part; I followed _that specific_ top google result plus a few others, dug around in RamMap, but couldn't find anything to finger any particular process as owning all the consumed Ram. Admittedly a bit out of my league in terms of system level debugging here, but all of the typical culprits said "everything looks normal except you actually have like no ram free," and given that it was impeding my primary work machine + that I had no track record of these symptoms occurring before, I eventually resigned myself to a reboot.