Hi Arnd,
when using the ppc64 compiler from kernel.org, I see the following problems when trying to compile ppc:allnoconfig in v4.14.y or v4.16.y.
gcc 7.3.0: Compilation of kernel.cpu.o hangs
The problem goes away if I apply the following two patches (tested with 4.16.y)
17a2f1ced028 cpu/hotplug: Merge cpuhp_bp_states and cpuhp_ap_states fcb3029a8d89 cpu/hotplug: Fix unused function warning
gcc 8.1.0: Compilation of kernel/cpu.o results in the following error
powerpc64-linux-gcc: error: unrecognized command line option '-mno-spe'; did you mean '-fno-see'? powerpc64-linux-gcc: error: unrecognized command line option '-mspe=no'; did you mean '-misel=no'?
This problem is also seen with mainline.
With ppc:defconfig, kernel/cpu.o builds fine with both compiler versions.
Have you seen similar problems ? Any idea what to do about it, other than sticking with older compilers ?
Thanks, Guenter