Played a bit with GALLIUM_HUD.
Using:
GALLIUM_HUD="fps,cpu,ps-invocations+hs-invocations+ds-invocations+cs-invocations;num-compilations+num-shaders-created,draw-calls,buffer-wait-time;num-cs-flushes,num-bytes-moved;VRAM-usage+GTT-usage,GPU-load,temperature,shader-clock+memory-clock"

I can play for some minutes before the game crashes (but doesn't kill the box)
and the trace looks like this:

#0  0x00007f22458745ac hud_draw_string (radeonsi_dri.so)
#1  0x00007f2245874e28 hud_draw (radeonsi_dri.so)

I guess this is a GALLIUM_HUD bug.

Any metric that might be of particular interest?