* Ingo Molnar <[EMAIL PROTECTED]> wrote:
> it seems you've got hpet active by default:
>
> /sys/devices/system/clocksource/clocksource0/current_clocksource:
> hpet
> /sys/devices/system/clocksource/clocksource0/available_clocksource:
> hpet acpi_pm pit jiffies tsc
btw., it's quite mysterious how this can lock up. ktime_get() on a hpet
clocksource does a very straightforward:
static cycle_t read_hpet(void)
{
return (cycle_t)hpet_readl(HPET_COUNTER);
}
which is a very simple thing:
c0119470 <hpet_readl>:
c0119470: 8b 15 b8 b4 ae c0 mov 0xc0aeb4b8,%edx
c0119476: 55 push %ebp
c0119477: 89 e5 mov %esp,%ebp
c0119479: 5d pop %ebp
c011947a: 01 d0 add %edx,%eax
c011947c: 8b 00 mov (%eax),%eax
c011947e: c3 ret
basically just a memory access to an ioremap()-ed area.
hm, perhaps it's due to the xtime lock dependency:
do {
seq = read_seqbegin(&xtime_lock);
getnstimeofday(ts);
tomono = wall_to_monotonic;
} while (read_seqretry(&xtime_lock, seq));
perhaps your system somehow generates a printk from within an xtime_lock
locked section?
Ingo
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