Re: Strange lockup on MP macppcs

[Martin Husemann <martin%duskware.de@localhost>]

On Tue, Jun 28, 2022 at 06:15:15PM +0200, Martin Husemann wrote:
> Since I can't run a full grown DIAGNOSTIC/DEBUG/LOCKDEBUG kernel I have
> a hard time figuring out exact details - anyone happen to have a good
> idea?

I noticed that in at least the last few cases I caugtht I have
this kernel thread active:

0    > 115 7   1       200           10428680          nd6_timer


db{0}> bt/a 10428680
trace: pid 0 lid 115 at 0x10423c20
0x10423c80: at softint_fast_dispatch+0x40
0x10423ca0: at kernconfig_recurse+0x10
0x10423cf0: at kernconfig_recurse+0x10
0x10423d10: at cpu_info+0xa7c
0x10423d20: at callout_hardclock+0x28
0x10423d40: at decr_intr+0x174
0x10423d70: at trapstart+0x800
0x10423e40: at cpu_info+0xa7c
0x10423e80: at nd6_timer_work+0x64
0x10423ee0: at workqueue_worker+0x134


... and I have seen network timer deadlocks on aarch64 machines recently,
so maybe this is another instance of that issue?

Or something is broken with ppc fast softints?

Martin