2007-10-04 22:20:39

by Steven Rostedt

[permalink] [raw]
Subject: 2.6.23-rc9-rt2

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







2007-10-07 13:35:29

by Jaswinder Singh

[permalink] [raw]
Subject: Re: 2.6.23-rc9-rt2

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 <[email protected]> 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
>
>
>
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2007-10-08 13:52:52

by Steven Rostedt

[permalink] [raw]
Subject: Re: 2.6.23-rc9-rt2


--
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

2007-10-08 14:34:36

by Jaswinder Singh

[permalink] [raw]
Subject: Re: 2.6.23-rc9-rt2

Hi Steve,

On 10/8/07, Steven Rostedt <[email protected]> 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.

2007-10-08 15:08:16

by Thomas Gleixner

[permalink] [raw]
Subject: Re: 2.6.23-rc9-rt2

On Mon, 8 Oct 2007, Jaswinder Singh wrote:
> On 10/8/07, Steven Rostedt <[email protected]> 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