* Anton Blanchard <an...@samba.org> wrote:
> +static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
> +static int die_owner = -1;
> +static unsigned int die_nest_count;
> +
> +unsigned long __die_spin_lock_irqsave(void)
> +{
> + unsigned long flags;
> + int cpu;
> +
> + /* racy, but better than risking deadlock. */
> + raw_local_irq_save(flags);
> +
> + cpu = smp_processor_id();
> + if (!arch_spin_trylock(&die_lock)) {
> + if (cpu != die_owner)
> + arch_spin_lock(&die_lock);
So why not trylock and time out here after a few seconds,
instead of indefinitely supressing some potentially vital
output due to some other CPU crashing/locking with the lock
held?
> + }
> + die_nest_count++;
> + die_owner = cpu;
> +
> + return flags;
I suspect this would work in most cases.
If we fix the deadlock potential, and get a true global
ordering of various oopses/warnings as they triggered (or
at least timestamping them), then I'm sold on this I guess,
it will likely improve things.
Thanks,
Ingo
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