On Mon, Oct 24, 2016 at 7:51 AM, Thomas Gleixner <t...@linutronix.de> wrote:
>
> Can you please check in the disassembly whether gcc really reloads
> timer->flags? Mine does not...
No, me neither. The code generation for lock_timer_base() looks
reasonable, although not pretty (it needs one spill for the
complexities in get_timer_cpu_base(), and the "*flags" games results
in some unnecessary indirection too).
I will try your patch, but also stare at my code some more.
I'm starting to think that the problem could be due to the timer code
being triggered _way_ too early (printk() ends up being obviously used
long before most things end up using timers), and that the problem I
see is just later fallout from that.
Sergey (added to participants) tried an earlier version of my patch,
and had more debug options enabled, and got
BUG: spinlock bad magic on CPU#0
from mod_timer() doing _raw_spin_unlock_irqrestore(), when the
printk() callchain happens very early in setup_arch ->
setup_memory_map -> e820_print_map().
So I think the timer bugs I found were _potentially_ true bugs, but
likely not the cause of this all.
init_timers() happens early, but we do printk's even earlier.
I'll add a "if (system_state > SYSTEM_BOOTING)" or something to test
that theory.
Linus
