Created attachment 132229 [details]
Tested with my RX 480 on mesa git and Linux 4.11 and 4.12-rc.
To reproduce, get https://github.com/ethereum-mining/ethminer
in libethash-cl/ethash_cl_miner_kernel.cl add
#pragma OPENCL EXTENSION cl_clang_storage_class_specifiers : enable
then cmake . and make and in ethminer/ run ./ethminer -G --benchmark
it outputs some progress and at 97% something goes wrong and I get GPU faults and/or GPU hangs.
Interestingly with the closed source OpenCL runtime from amdgpu-pro it fails at 97% too.
Created attachment 132290 [details]
Thanks to a tip from tom stellard I tried it without X (after exiting sddm).
I've tried to start the miner with "real work" from a pool as recommended:
GPU_FORCE_64BIT_PTR=0 GPU_MAX_HEAP_SIZE=100 GPU_USE_SYNC_OBJECTS=1 GPU_MAX_ALLOC_PERCENT=100 GPU_SINGLE_ALLOC_PERCENT=100 ./ethminer --farm-recheck 200 -G -S eu1.ethermine.org:4444 etc. etc.
I get gpu faults, but no hangs or other issues and the system is usable normally after exiting the miner.
The -G --benchmark mode still has worse troubles with hangs etc.