2.6.23-rc9-rt2

2.6.23-rc9-rt2

[Steven Rostedt]

We are pleased to announce the 2.6.23-rc9-rt2 tree, which can be
downloaded from the new location:

 http://www.kernel.org/pub/linux/kernel/projects/rt/

Changes since 2.6.23-rc9-rt1

  - x86_64 disable IST for debug (Andi Kleen)

  - Better handling of dynticks going bad in RCU (Steven Rostedt)

  - Preempt RCU boosting (Steven Rostedt based on Paul E. McKenney's 
    stuff)

Again, this still holds experimental code. But I've been running it on a
few boxes already (and even the box I'm writing this on). 

to build a 2.6.23-rc9-rt2 tree, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.22.tar.bz2
  http://www.kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6.23-rc9.bz2
  http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.23-rc9-rt2.bz2

The broken out patches are also available.

-- Steve

Re: 2.6.23-rc9-rt2

[Jaswinder Singh]

Hello Steve,

Do you have any plans to support nested or reentrant Interrupt Handling schemes.

Thank you,

Jaswinder SIngh.

On 10/5/07, Steven Rostedt <rostedt@goodmis.org> wrote:
> We are pleased to announce the 2.6.23-rc9-rt2 tree, which can be
> downloaded from the new location:
>
>  http://www.kernel.org/pub/linux/kernel/projects/rt/
>
> Changes since 2.6.23-rc9-rt1
>
>   - x86_64 disable IST for debug (Andi Kleen)
>
>   - Better handling of dynticks going bad in RCU (Steven Rostedt)
>
>   - Preempt RCU boosting (Steven Rostedt based on Paul E. McKenney's
>     stuff)
>
> Again, this still holds experimental code. But I've been running it on a
> few boxes already (and even the box I'm writing this on).
>
> to build a 2.6.23-rc9-rt2 tree, the following patches should be applied:
>
>   http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.22.tar.bz2
>   http://www.kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6.23-rc9.bz2
>   http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.23-rc9-rt2.bz2
>
> The broken out patches are also available.
>
> -- Steve
>
>
>
>
>
>
> -
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>

Re: 2.6.23-rc9-rt2

[Steven Rostedt]

--
On Sun, 7 Oct 2007, Jaswinder Singh wrote:

> Do you have any plans to support nested or reentrant Interrupt Handling schemes.
>

Hi Jaswinder,

Not sure what you mean by this, since interrupt handlers are run as
threads and are fully preemptible.

-- Steve

Re: 2.6.23-rc9-rt2

[Jaswinder Singh]

Hi Steve,

On 10/8/07, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> --
> On Sun, 7 Oct 2007, Jaswinder Singh wrote:
>
> > Do you have any plans to support nested or reentrant Interrupt Handling schemes.
> >
>
> Hi Jaswinder,
>
> 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.

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

Thank you,

Jaswinder SIngh.

Re: 2.6.23-rc9-rt2

[Thomas Gleixner]

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