Re: 2.6.23-rc9-rt2

[Thomas Gleixner <tglx@linutronix.de>]

On Mon, 8 Oct 2007, Jaswinder Singh wrote:
> On 10/8/07, Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > Not sure what you mean by this, since interrupt handlers are run as
> > threads and are fully preemptible.
> >
> I think by nested or reentrant interrupt handling technique you can
> further reduce latencies.
> what you think.

Interrupt handlers in vanilla Linux and preempt-rt are never reentrant. 
There is no advantage of allowing interrupt handler reentrancy, quite the 
contrary it makes the code more complex.

The interrupt handlers in preempt-rt are running in threads. One thread 
per interrupt, so depending on the thread priority the handlers a handler 
of one interrupt can preempt the running handler of another interrupt.

> Can we can get guaranteed realtime throughput by using these realtime patch.

Realtime is not about throughput. It's about determinism.

	tglx