lkml.org 
[lkml]   [2004]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: USB making time drift [was Re: dynamic-hz]
Date
On Wednesday 15 December 2004 13:20, Andrea Arcangeli wrote:
>On Wed, Dec 15, 2004 at 11:44:38AM -0500, Gene Heskett wrote:
>> The HZ=1000 is the culprit?
>
>HZ=1000 isn't the culprit. The culprit is the >1msec latency of the
> usb irq, but that wouldn't be visible with HZ 100 (for this
:> specific case HZ=100 would only be a band-aid).
>
>> Onboard AC-97 audio of course. Crappy stuff... [..]
>
>I doubt it's the chip, but only the motherboard to blame. My laptop
> has the ac97 but no HZ sound out of it.
>
>> translate to 10 millisecond intervals. If you had a 4 millisecond
>> latency,
>> that would be spread over 4 of the 1000 hz interrupts. That
>> sounds rather confusing to the service routine I imagine.
>
>The ones that get confused are the system time and the jiffies, the
> rest of the system can deal with long irq delays. The tick
> adjustment was exactly implemented so that the jiffies and system
> time wouldn't get confused anymore, but it just confuses it the
> other way around in my current experience.
>
>> I'll do that just for grins & report back.
>
>Ok.

Unforch, I was not able to find that in the .config file, so where is
that particular option set?

--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.30% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attorneys please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.

-
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 14:08    [W:0.099 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site