L4Linux update? Driver support

Adam Lackorzynski adam at os.inf.tu-dresden.de
Tue Nov 24 22:05:20 CET 2015


On Mon Nov 23, 2015 at 22:09:47 +0800, li94575 wrote:
> At 2015-11-22 23:42:55, "Adam Lackorzynski" <adam at os.inf.tu-dresden.de> wrote:
> >hi,
> >
> >On Sun Nov 22, 2015 at 22:07:46 +0800, li94575 wrote:
> >> hello Adam,
> >> I also have a question about the Interrupt mechanism in l4linux. I want to move some interrupts to specified cpu core. When I try to write to "/proc/irq/*/smp_affinity" with cpu bitmask, it will call the function l4lx_irq_dev_set_affinity(), which attachs the irq to corresponding vcpu thread. After that, I find the irq is still staying on previous cpu core through linux proc system. So I doubt whether linux proc filesystem's view is synchronized with the interrupt settings of the L4 kernel, or it can not be achieved in l4linux?  (I use genode for the runtime environment of fiasco.oc)
> >
> >The l4lx_irq_dev_set_affinity function that is called by Linux
> >interrupt code, i.e. I think all the book keeping shall be done by the
> >Linux code, including the output of /proc/interrupts.
> >You should check in the jdb to which thread the interrupt is attached.
> >You can see this in the object list, use shift-Q to see it.
> >WIth CONFIG_L4_DEBUG_REGISTER_NAMES=y enabled in L4Linux, you'll have
> >proper descriptions of the objects, so you'll find the interrupt you're
> >looking for: l4lx.irqXX with XX being the same number as in
> >/proc/interrupts. 
> >Then, look for the T= value of that particular interrupt, it points to
> >the thread the interrupt is attached to. Pressing TAB brings you to the
> >thread in the list. Is it the right onw?
> >I have tried your methed in the jdb, and find all the irqs we used is on the same thread( on cpu0 ) which has no name.But CONFIG_L4_DEBUG_REGISTER_NAMES is enabled in L4Linux. Regardless of how the irq setting in L4Linux, it alwaysstays the same in the jdb, this makes me so confused.

When setting the affinity, does it use the proper new CPU number in
attach_to_irq? Also change the dd_printk to printk to see whether the
attach might go wrong (also do this in detach_from_interrupt). Any error
messages displayed now?



Adam
-- 
Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/



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