Re: Real-Time Preemption -RT-V0.7.51-17 - Keyboard Problems
From: K.R. Foley
Date: Fri Jul 08 2005 - 16:34:34 EST
Ingo Molnar wrote:
* K.R. Foley <kr@xxxxxxxxxx> wrote:
Ingo,
I have an issue with keys VERY SPORADICALLY repeating, SOMETIMES, when
running the RT patches. The problem manifests itself as if the key
were stuck but happens far too quickly for that to be the case. I
realize that the statements above are far from scientific, but I can't
seem to narrow it down further. 2.6.12 doesn't seem to have the
problem at all, only when running the RT patches. It SEEMS to have
gotten worse lately. I am attaching my config as well as the output
from lspci.
Adjusting the delay in the keyboard repeat seems to help. Any ideas?
hm. Would be nice to somehow find a condition that triggers it. One
possibility is that something else is starving the keyboard handling
path. Right now it's handled via workqueues, which live in keventd. Do
things improve if you chrt keventd up to prio 99? Also i'd chrt the
keyboard IRQ thread up to prio 99 too.
I would like very much to come up with a condition that causes it.
Unfortunately, the only event that I know of that is associated with
this typing. :-) There does not seem to be a method to the madness.
As for bumping the priorities, I tried them all, at least the ones
mentioned above. I also tried the timer just for grins, after changing
the keyboard repeat delay seemed to help a bit. None of them seemed to
help, at least not for an extended period of time.
the other possibility is some IRQ handling bug - those are usually
specific to the IRQ controller, so try turning off (or on) the IO-APIC
[if the box has an IO-APIC], does that change anything?
You may be on to something here. Booting with noapic SEEMS to help.
Ingo
--
kr
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