Re: What is wrong with kernels 5.X on sparc64 ?

[Meelis Roos <mroos@linux.ee>]

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 <mroos@linux.ee>