Status of Linux 2.6 for 40x and 44x CPUs

Status of Linux 2.6 for 40x and 44x CPUs

[llandre]

Hi all,

I found some messages about the status of 2.6 kernel for MPC8xx-based 
machines but
I found nothing about 40x and 44x CPU. Anybody can tell me something about 
it? Did it
get production stable? If not, which are the areas that are under heavy 
development?



Many thanks in advance,

llandre

DAVE Electronics System House - R&D Department
web:   http://www.dave-tech.it
email: r&d2@dave-tech.it

Re: Status of Linux 2.6 for 40x and 44x CPUs

[Eugene Surovegin]

On Wed, Apr 06, 2005 at 09:41:27AM +0200, llandre wrote:
> I found some messages about the status of 2.6 kernel for MPC8xx-based 
> machines but
> I found nothing about 40x and 44x CPU. 

So what? Absence of such messages doesn't mean 4xx doesn't work, I'd 
say quite the opposite.

> Anybody can tell me something about 
> it? Did it
> get production stable? If not, which are the areas that are under heavy 
> development?

4xx is quite stable, although I'm not sure many people use 2.6 in 
production.

--
Eugene

Re: Status of Linux 2.6 for 40x and 44x CPUs

[Glenn Burkhardt]

=46rom the looks of the benchmarks described here:

http://www.denx.de/twiki/bin/view/Know/Linux24vs26

and the results are basically confirmed here:

http://www.2cpu.com/articles/98_1.html

there are good reasons to avoid using the 2.6 kernel.  Frankly, I'm surpris=
ed=20
and would have thought that the changes in the scheduler would have brought=
=20
improvements, as did the report here:

http://www.lynuxworks.com/corporate/news/2004/linux-kernel-2.6.php

But it looks like the major improvements are in filesystem performance, so =
for=20
embedded use, 2.4 will be around for quite a while.

Re: Status of Linux 2.6 for 40x and 44x CPUs

[Roger Larsson]

On Wednesday 27 April 2005 18.33, Glenn Burkhardt wrote:
> From the looks of the benchmarks described here:
>
> http://www.denx.de/twiki/bin/view/Know/Linux24vs26
>
> and the results are basically confirmed here:
>
> http://www.2cpu.com/articles/98_1.html
>
> there are good reasons to avoid using the 2.6 kernel.  Frankly, I'm
> surprised and would have thought that the changes in the scheduler would
> have brought improvements, as did the report here:
>
> http://www.lynuxworks.com/corporate/news/2004/linux-kernel-2.6.php

At all depends on what you measure (and that you actually measure
what you think you are measuring :-)

"A PREEMPTIBLE KERNEL."

  This is about how quick your higher priority thread actually gets to run
  after an event (i.e. driver to application). It is not about how fast the
  context switch itself is.

  Why 2.4 might be faster:
     Measure context switch time where one process wakes up another
     while going to sleep has less overhead.

  Modified test
    Let the above processes run with SCHED_RR or SCHED_FIFO
    add a third process that uses the kernel a lot - like memory management.

"AN EFFICIENT SCHEDULER"

  This is more about what will happen if you have more than a few processes
  in the run queue - avoids searching all of them...

  Why 2.4 might be faster:
   A search of a list with only one element is hard to beat!
   But try to measure using lots of processes running at the same time.

/RogerL

Re: Status of Linux 2.6 for 40x and 44x CPUs

[Wolfgang Denk]

In message <200504280029.35461.roger.larsson@norran.net> you wrote:
>
> At all depends on what you measure (and that you actually measure
> what you think you are measuring :-)

Can you recommend another benchmark test that would provide a  better
representation of typical user space workloads than lmbench does?

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
Old programmers never die, they just branch to a new address.