Using 314b658 with amdgpu, starting sway and firefox causes "BUG: Bad rss-counter state" and "BUG: non-zero pgtables_bytes on freeing mm" to start filling dmesg, and then closing programs causes more BUGs and hangs, and then everything grinds to a halt (can't start more programs, can't even reboot through systemd). Using master and reverting that branch up to that point fixes the problem. I'm using a Ryzen 1600 and AMD Radeon RX 480 on an ASRock B450 Pro4 board with IOMMU enabled.
