Fernando, Thanks very much for your help. I read the entire 5105 kernel bug discussion and didn't find the valuable information you presented, i.e. how to change the clocksource at runtime so easily. I was going to try the "notsc" kernel option. For what it's worth I changed the clocksource as you mentioned and I haven't had a glitch yet (10 minutes since the change).. and this is unusual. Aaron On 11/21/05, Fernando Lopez-Lezcano <nando@xxxxxxxxxxxxxxxxxx> wrote: > On Mon, 2005-11-21 at 15:25 -0500, Aaron Phillips wrote: > > > Which cpu do you have? > > I have AMD X2 also, the AMD X2 3800, interesting... > > > > > I have seen this coupled also to keyboard repeats > > > being too fast because of kernel problems in keeping time (in my case > > > related to using AMD X2 dual core processors). > > Really? well should I turn down repeats in the BIOS or in Linux? > > > > > The X blackouts were actually the screensaver kicking in. It is supposed to be fixed... > > In which version is it supposed to be fixed. I am using the latest > > and greatest 2.6.14 plus the latest RT patch (rt13). The only thing I > > don't quite understand is what to do with the post-release version > > increments such as 2.6.14.2.. how do you patch that? > > > > Which kernel are you running and do you have the same problem still? > > I still have the problem and it is not fixed yet (just earlier today I > think I finally understood what is actually happening). > > At this point this only happens on dual core systems (for example the > Athlon X2 processor family) running an SMP i386 kernel, it does not > happen on x86_64 systems. A patch has just been posted to lkml (by John > Stultz) that should take care of this, but it will take a while for the > stuff to get to the -rtxx patches. > > There is a workaround (thanks to John Stultz) which is to change the > source clock for the timing to something other than the TSC[*]. You can > see which source is being used by typing: > > cat /sys/devices/system/clocksource/clocksource0/clocksource > > The default should show something like this: > > acpi_pm jiffies *tsc pit > > note the "*" next to tsc, means it is the one being used. > If you have acpi_pm change the source to it like this: > > echo "acpi_pm">/sys/devices/system/clocksource/clocksource0/clocksource > > That should fix the problem you are having. > > You can also add "clocksource=xyz" as a boot time kernel parameter, > where xyz is the source you want to use. > > -- Fernando > > [*] "Time Stamp Clock": on Athlon X2 systems each cpu has its own and > they can drift from each other, software that does not take this into > account gets into big trouble, for example Jack. > > >
