Re: [v4.1.10-rt10][PATCH 1/2] genirq: introduce new generic_handle_irq_rt_wa() api

[Grygorii Strashko]

Hi Thomas, Sebastian,

On 11/03/2015 10:18 PM, Sebastian Andrzej Siewior wrote:
> On 11/03/2015 08:51 PM, Thomas Gleixner wrote:
> > > where MAX_MSI_IRQS = 32 now, but potentially can be increased up to 256.
> >
> > And you really oversimplified the code above. The reality is:
> >
> >      for (i = 0; i < MAX_MSI_CTRLS: i++) {
> >      	u32 status = read_msi_ctrl(i);
> >
> > 	for_each_bit(status)
> > 		handle_irq();
> >      }
> >
> > So sure, the worst case here is MAX_MSI_CTRLS * 32, but if all
> > possible 256 MSI interrupts are pending at the same time, you have
> > other problems than that.
>
> With threaded interrupts we would have 256 invocations of
> wake_up_process() so nothing should take ages.

Thanks a lot for your time and comments - I'll follow your
recommendations and use IRQF_NO_THREAD.

--
regards,
-grygorii
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/