lkml.org 
[lkml]   [2012]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: IRQ affinity enforced only after first interrupt.
Date
> > >
> > > The architecture specific code will determine whether the IRQ could be migrated
> > > in process context. For example, the IRQ_MOVE_PCNTXT flag will be set on x86
> > > systems if interrupt remapping is enabled.
> >
> > Actually I am encountering this issue with x86, and see different
> > behavior with different HW devices (NICs). On same machine I have
> > one device that responds immediately to affinity changes while the
> > other one changes the affinity only after first interrupt.
>
> That simply depends on the underlying hardware. On certain hardware we
> can change the affinity only in hard interrupt context, that means
> right when a interrupt of that device is delivered.
>
> On the other devices we can change it right away and the corresponding
> interrupt chips set IRQ_MOVE_PCNTXT to indicate that.
>
> There is nothing we can do about this. It's dictated by hardware.
>

Thanks for the explanation,
Which capabilities of the HW show whether IRQ_MOVE_PCNTXT can be set or not?
Is it done by reading configuration from PCI?

Thanks,
Yevgeny


\
 
 \ /
  Last update: 2012-03-27 11:41    [W:1.139 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site