I wrote:
I restarted the kernel config bisection using 5.6.0-12706-gb032227c6293 and current gcc-9 (9.3.0 - Debian 9.3.0-10). So far I have not found a working configuration yet.
I have found a configuration from previous testing that gives me a working kernel with gcc-9.3. Bisecting the configuration now - it appears I have to "make clean" before each compilation or I will get partly old kernel that behaves differently when recompiled after "make clean".
From previous bisection saved configs and notes I came to a preliminary conclusion that when I turn off SMP from working configuration, I get a nonworking configuration that differs a lot (different RCU implementation chosen etc).
This hypothesis still seems to hold with gcc-9 (my latest working kernel is SMP and a nonworking one is !SMP). Will keep bisecting.
I installed Debians latest UP (5.5.0-2-sparc64) and SMP (5.5.0-2-sparc64-smp) kernels on my single-CPU Ultra 45 and they both work for simple "apt update && apt install some-single-package" test. Earlier 5.2.0-3-sparc64 kernel also works well for compiling other kernels.
Also, 5.5.0-1-sparc64 works. -- Meelis Roos <[email protected]>
