NForce2, Ross Dickson's timer patch on 2.6.1

From: Jesse Allen (the3dfxdude_at_hotmail.com)
Date: 01/12/04

  • Next message: Jesse Allen: "Re: 2.6.1-mm1" 
    Date:	Mon, 12 Jan 2004 10:35:54 -0700
To: ross@datscreative.com.au

    Hi Ross,

    I have a version of your timer patch (io_apic.c) for kernel 2.6.1. It is
    attached. I have been monitoring a problem with it. It seems that with the
    patch, I gain 1 seconds time over 10 minutes (roughly). So I gain about 2-3
    mintues a day. I haven't taken exact measurements, but I know it ends up about
    20 minutes difference after a week. This is not good, which would require
    resetting the time often.

    I tried the 2.6.1 kernel without the timer patch. The timer is now back in PIC
    mode, and interrupt 7 has the old noise. Synched the time with my watch. At
    first, I noticed no gain in time over 10 minutes. However the next day, I found
    it gained 1-2 seconds. Now it is about 7 seconds ahead a few days later now.
    This is much better.

    So I'm left to thinking, the patch does two things, maybe one thing right, and
    one possibly very wrong:

    1) It does place the timer in APIC mode.
    2) But the timer seems to be fed extra interrupts, maybe the same that is found
    on irq 7 without the patch (is this possible?)

    I remember someone making a comment which might explain the issue:
    http://marc.theaimsgroup.com/?l=linux-kernel&m=107098440019588&w=2

    I don't think the patch was much different now than it was then. So I think
    there is something wrong with setting up the timer this way. I don't know if
    you worked something out with Maciej. I don't know much about interrupt
    controller programming so... if maybe you can explain to me anything I'm
    missing. For now I've dropped the patch.

    Jesse

    PS: I have run with disconnect on, and without your ack patch since I got that
    surpise BIOS update. No lockups have occurred in the past month, since that. So the disconnect problem is a BIOS bug. (Shuttle has not responded)

    PSS: CC me, I'm not subscribed right now.

    -
    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/

  • Next message: Jesse Allen: "Re: 2.6.1-mm1"

    Relevant Pages

    • [PATCH] cs4236.c, kernel 2.6.11
      ... in sound/isa/cs423x/ in the Linux 2.6.11 kernel. ... The card/chipset supports an external MIDI interrupt. ... this interrupt isn't used (because the isapnp mechanism chooses ... Before applying the patch: ...
      (Linux-Kernel)
    • Re: [PATCH 1/2] Dynamic Tick: Prevent clocksource wrapping during idle
      ... The dynamic tick allows the kernel to sleep for periods longer ... This patch prevents that the kernel from ... kernel can sleep for a given clocksource and function called ... there is no timer pending or at least extremly far ...
      (Linux-Kernel)
    • Re: select & gettimeofday
      ... > timer, and since you would usaully use it to poll some fds, it will ... > break either before the timeout value (due to a descriptor becoming ... The kernel on the 2.6.1 machine is SMP, ... But I don't know if the patch has made it into 2.6 (I think ...
      (comp.os.linux.development.system)
    • Re: One-shot-oriented event timers management
      ... This behavior leads me to suspect that the timer interrupts had stopped ... One-shot timers have one weak side: if for some reason timer interrupt ... Patch also includes some optimizations to reduce lock contention. ... test patches are always welcome:) ...
      (freebsd-current)
    • Re: One-shot-oriented event timers management
      ... This behavior leads me to suspect that the timer interrupts had stopped ... One-shot timers have one weak side: if for some reason timer interrupt ... Patch also includes some optimizations to reduce lock contention. ... test patches are always welcome:) ...
      (freebsd-hackers)