[LAU] Too many xruns

[Jeremy Jongepier]

On 10/11/2012 10:06 AM, Kevin Cosgrove wrote:
> A comment at the above link says, "If [the grep command]
> returns CONFIG_IRQ_FORCED_THREADING=y and CONFIG_PREEMPT=y
> then your kernel is using IRQ threading and you don't have
> to proceed with the following steps. If it only returns
> CONFIG_IRQ_FORCED_THREADING=y you can add the threadirqs boot
> option as described..."  My grep was in the 2nd case, with
> only CONFIG_IRQ_FORCED_THREADING set to "y", so I proceeded
> with the rest of the "threadirqs" instructions related to grub.
> That didn't seem to work.
>

Ok, thanks for the info, I should change that section in the Wiki then. 
I think you need at least PREEMPT__LL, so with PREEMPT_NONE or 
PREEMPT_VOLUNTARY threadirqs could not work. And you're using 
PREEMPT_VOLUNTARY.

>>> > >      I altered my /boot/grub2/grub.cfg file to include
>>> > >      "threadirqs" on the stanza for my kernel, like so, but
>>> > >      without all the line breaks.
>>> > >
>>> > >      linux   /boot/vmlinuz-3.5.5-2.fc17.x86_64
>>> > >      root=UUID=77edf07a-a49b-48dd-82c8-2f9e5c8691b7 ro nomodeset
>>> > >      rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=True  KEYTABLE=us rd.luks=0
>>> > >      LANG=en_US.UTF-8 rhgb quiet threadirqs nouveau.modeset=0
>>> > >      rd.driver.blacklist=nouveau
>>> > >
>> >
>> >Slightly OT, but wow, that's a whole lot of kernel options;)  I only use
>> >two or three.
> I left all of that in there from Fedora's installation of the kernel.
>
>> >Check if your kernel is preemtible (at least, I think that might be a
>> >probable cause) or install a kernel that is preemtible
> # CONFIG_PREEMPT_RCU is not set
> CONFIG_PREEMPT_NOTIFIERS=y
> # CONFIG_PREEMPT_NONE is not set
> CONFIG_PREEMPT_VOLUNTARY=y
> # CONFIG_PREEMPT is not set
>
>> >(there's no real-time kernel available for FC17?).
> CCRMA has kernel-rt-3.4.11-1.rt19.2.fc17.ccrma.x86_64 but it
> doesn't play nicely with my nVidia card and X config.  I changed
> the X config to use the nouveau driver, which got it to boot to
> level 5 at least.  But the geometry is not good and that driver
> ignores my 2nd display.  I found A LOT of potentially useful
> information with a websearch for enabling an nVidia driver with a
> CCRMA kernel.  Sorting that out is a possibility.
>

I'd go for that. Fwiw, I have been using the nouveau driver succesfully 
quite a while now. But then I'm using an older card.

Best,

Jeremy
> Thanks....
>
> --
> Kevin