Re: Real-Time Preemption -RT-V0.7.51-17 - Keyboard Problems

[Doug Maxey <dwm@maxeymade.com>]

On Fri, 08 Jul 2005 21:13:26 +0200, Ingo Molnar wrote:
>
>* K.R. Foley <kr@cybsft.com> 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?

Is the keyboard standard (PS2) or USB?  Did not see the detail.

>
>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.
>
>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?

FWIW, I have seen this issue under USB, off and on since about 2.6.9.
Never have dug into it, was always simpler to just unplug and re-plug
the keyboard.  Of course, this predates RT.

++doug

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