Not strictly accurate, in the "Why would you want to do this" regard.
Ages ago I was hacking linux onto an ARM soc that claimed to have memory it didn't (it wasn't aware of the display's DMA segment). It was near the top of the address space, so generally speaking it didn't cause too many problems, but until I could debug it I needed to keep memory usage low, wchih meant disabling the disk cache. What a shitshow that was :/
Ages ago I was hacking linux onto an ARM soc that claimed to have memory it didn't (it wasn't aware of the display's DMA segment). It was near the top of the address space, so generally speaking it didn't cause too many problems, but until I could debug it I needed to keep memory usage low, wchih meant disabling the disk cache. What a shitshow that was :/