Messages in this thread | | | From | Gene Heskett <> | Subject | Re: USB making time drift [was Re: dynamic-hz] | Date | Wed, 15 Dec 2004 20:59:52 -0500 |
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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.
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