lkml.org 
[lkml]   [2003]   [Nov]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] amd76x_pm on 2.6.0-test9 cleanup
From
On Tuesday, November 4, 2003, at 03:05 PM, Tony Lindgren wrote:

> * Charles Lepple <clepple@ghz.cc> [031104 11:45]:
>> On Tuesday 04 November 2003 02:15 pm, Tony Lindgren wrote:
>>> I've heard of timing problems if it's compiled in, but supposedly
>>> they
>>> don't happen when loaded as module.
>>
>> In some of the earlier testX versions of the kernel, I did not see any
>> difference between compiling as a module, and compiling into the
>> kernel. (It
>> is currently a module on my system.)
>>
>> I did, however, manage to keep ntpd happy by reducing HZ to 100. Even
>> raising
>> HZ to 200 is enough to throw off its PLL. The machine is idle for 90%
>> of the
>> day, though, so I don't know if the PLL is adapting to the fact that
>> the
>> system is idling, but the values for tick look reasonable.
>
> Interesting, sounds like the idling causes missed timer interrupts?
> Can you
> briefly describe what's the easiest way to reproduce the timer
> problem, just
> change HZ to 200 and look at the system time?

Weird. On -test9-bk at HZ=1000, with amd76x_pm loaded as a module
(lazy_idle=800, the default), the system clock is running fast.

With ntpd running, the clock was stepped back 2.5 seconds twice in 20
minutes.

Here's what I get from adjtimexconfig (after stopping ntpd, of course):

# adjtimexconfig
Comparing clocks (this will take 70 sec)... adjusting system time by
-126.211 sec/day
Done

Now tick is 9985. I distinctly remember it being somewhat over 10,000
the last time I ran with HZ=1000 and amd_76x_pm active. With HZ=100,
adjtimexconfig sets tick=10002.

I'm not entirely sure what the "acpi" interrupt is doing-- it
increments about once every two seconds when the system is idle, and
various types of system activity make it happen more frequently. At
least I'm not getting any "irq 9: nobody cared!" messages anymore (the
button module is loaded, so I guess it is handling it). If I don't have
amd76x_pm loaded, the acpi interrupt is triggered a couple of times
after button is loaded, but then it doesn't happen again until I
actually press a button.

--
Charles Lepple
ghz.cc! clepple

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:58    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site