lkml.org 
[lkml]   [2008]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: X fails to start with latest Linus git

* Ingo Molnar <mingo@elte.hu> 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


\
 
 \ /
  Last update: 2008-01-27 13:45    [W:0.059 / U:2.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site