Re: [Xenomai] Can we have nested interrupt handling in Xenomai?

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On 08/22/2012 06:28 AM, ali hagigat wrote:
> Can we have nested interrupt handling in Xenomai? Suppose we are in
> the middle of an interrupt handler and a new interrupt comes in, CPU
> will start executing the handler of the new interrupt completely? or
> that interrupt is logged only for that domain to be serviced later?

No, we do not support nested interrupt. You should note that the Linux
kernel has stopped re-enabling hardware interrupts in the middle of the
interrupt handlers for some time now: if an interrupt handler takes a
long time to execute, then there is a bug in the interrupt handler. The
interrupt handler has to be fixed, re-enabling interrupts is a bad
workaround.

> 
> As far as I understood, when an interrupt comes, that interrupt is
> disabled and the domain pipeline is stalled and then the interrupt
> handler is called.
> When the interrupt handler returns, the domain pipeline is unstalled.
> Is that correct?

Not quite, it depends on which domain is current and which domain the
interrupt is for.

-- 
					    Gilles.