On Wed 2021-03-17 00:33:26, John Ogness wrote: > @syslog_log was a raw_spin_lock to simplify the transition of
s/syslog_log/syslog_lock/ Same problem is also below. > removing @logbuf_lock and the safe buffers. With that transition > complete, @syslog_log can become a spin_lock. I know that we already talked about this. But I want to be sure that this patch makes sense. It will actually not change the behavior because we always take the lock with interrupts disabled. We disable the interrupts because register_console() is called in IRQ context on parisc in handle_interruption() when it is going to panic (code == 1 => will call parisc_terminate()). Disabling IRQ will not help in parisc_terminate(). This code path is non-maskable and never returns. The deadlock might be prevented only by trylock. trylock on syslog_lock is only small problem. Much bigger is is a deadlock on console_lock. Fixing this is beyond this patchset. Summary: + disabling IRQ does not help for parisc + register_console() is not irq safe in general because of the sleeping console_lock. I would personally prefer to remove both "raw" and "irq" in this patch and just document the problem with parisc in the commit message. IMHO, it does not make sense to keep _irq when it neither helps nor makes sense. Best Regards, Petr