[ag-automation] Linux 2.6.18

[Luotao Fu]

Hi,

On Wed, Sep 20, 2006 at 05:42:27PM +0200, Thomas Gleixner wrote:
> As some of you might have already noticed, Linus Torvalds released
> 2.6.18 tonight.
> 
> Also the high resolution timer / dynamic tick patch set and the realtime
> preemption patch set have been refactored to the new kernel release.
> 
............
> 
> 2.6.18-rt1 is likely to be subtly broken, so we need as much testing and
> feedback as possible.
> 

Just done a quick test of the 2.6.18-rt3 on ARM plattform. Compiling 
with our toolchain (gcc4.0.2, softfloat) went through without big 
problems. As testhardware I took a board with xscale-pxa270 CPU and 
64MB RAM. IRQ Threading appear to work fine.:
ps -ef shows
......
root        81    14  0 00:00 ?        00:00:00 [IRQ 17]
root       222    14  4 00:00 ?        00:01:34 [IRQ 84]
root       225     1  0 00:00 ?        00:00:00 [mtdblockd]
root       237    14  0 00:00 ?        00:00:00 [IRQ 18]
root       242    14  0 00:00 ?        00:00:00 [IRQ 14]
......

I turned the wakeup latency tracer on and got some quite stable results.
We measure about 300us max. latency at heavy workload (cache calibrator
and fping), which is no higher than withou workload.

userspace Clock API, however, seems still not working properly, as I 
got funny values with clock_gettime() (from CLOCK_MONOTONIC source. Thus 
userspace measurmenttools like cyclictest still don't properly.

One more thing I detected is that the kernel appear to die away right
after unpacking if the profiling Latency Tracer (CONFIG_LATENCY_TRACE) is 
turned on. With this disabled it boots normally.

Regards
Luotao Fu

-- 
     Dipl.-Ing. Luotao Fu | http://www.pengutronix.de
  Pengutronix - Linux Solutions for Science and Industry
    Handelsregister: Amtsgericht Hildesheim, HRA 2686
      Hannoversche Str. 2, 31134 Hildesheim, Germany
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