Re: [regression] boot failure on alpha, bisected

On Sun, Oct 7, 2012 at 9:16 PM, Oleg Nesterov [off-list ref] wrote:

On 10/07, Thorsten Kranzkowski wrote:

quoted

On Sun, Oct 07, 2012 at 07:13:00PM +0200, Oleg Nesterov wrote:

quoted

On 10/07, Oleg Nesterov wrote:

quoted

Hmm. I know nothing about arch/alpha and I can't understand its entry.S.
But _it seems_ to me that do_notify_resume() is called with irqs disabled.
If this is true, then imho arch/alpha should be fixed.

Before this commit task_work_run() enabled irqs, but this was the "side
effect" of spin_lock_irq/spin_unlock_irq, we should not rely on this.

Could you please test the debugging patch below?

Of course. With that patch applied the kernel (ac3d0da) boots again. The trace line
is printed about once a second, with values '2' and '4'.

Thanks a lot Thorsten!

So I'll probably send the patch which enables interrupts in
task_work_run(). I guess this needs "if (irqs_disabled())"
for lockdep.

The question is, should I add the warning to remind that this
arch needs a fix?

Just wondering. As this is on an SMP system, perhaps the
read_barrier_depends() vs. smp_read_barrier_depends() matters
here?
http://lkml.indiana.edu/hypermail/linux/kernel/1209.3/00555.html

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds