I have now installed the i-pipe tracer and run some tests. Yesterday I thought I had gotten a high latency without X running, while compiling the kernel to stress the system, but now I think I might have been mistaken. Either way I was using a kernel whose configuration I couldn't remember, and didn't have the I-Pipe tracer installed at that time, so the observation wasn't particularly useful.
Today I have tried using the intel video driver with the option "NoAccel", and
that seems to stop the high latencies; with this option I can kill X, restart
it, and run glxgears without issues, all while compiling the linux kernel and
having xeno-test or latency running. The highest latency I have gotten so far
is 18uS.
However, if anyone is interested I have made a trace without the NoAccel
option, when the latency jumped to 1113uS upon starting X, attached.
A couple of other things:
Yesterday when running xeno-test, I got a few of these messages:
"INFO: task sync:20539 blocked for more than 120 seconds...."
I have not seen this again today, and I don't know if it could be related, but
I was also getting lots of strange USB disconnect sort of messages yesterday...
I haven't seen any more today, and as I said before that kernel may have been
useless anyway.
I am also getting this message from xeno-test:
"FATAL: module xeno-nucleus not found"
And:
"Warning Linux is compiled to use FPU in kernel space
For this reason, switch test can not test using FPU in Linux Kernel-space"
I presume these last two are because I did something wrong at kernel compile
time?
Also, I tried to compile Xenomai 2.5.4 with a 2.6.34 kernel because it has a
network driver that I really need, but the build failed. I think this has been
resolved previously (as I have seen some information in the mailing list about
a problem in the debian kernel patch script), but am not sure how to use the
corrected script with my system. Can anyone help?
I will keep testing.
Thanks,
Edward
On Monday, 16 August, 2010 1:32pm, "Gilles Chanteperdrix"
<gilles.chanteperd...@xenomai.org> said:
> edward.robb...@oxfordtechnologies.co.uk wrote:
>>
>> On Friday, 13 August, 2010 3:35pm, "Gilles Chanteperdrix"
>> <gilles.chanteperd...@xenomai.org> said:
>>
>>> edward.robb...@oxfordtechnologies.co.uk wrote:
>>>> I wonder if this is to do with graphics? I have set "NoAccel" in the
>>>> driver section of Xorg.conf (I am using fbdev). I also notice that
>>>> latencies go massive (e.g. 4200uS) the first time I run glxgears.
>>>> "glxinfo" reports "Direct rendering: no".
>>> This is bad news. It could come either from the fact that the Xorg
>>> driver shuts hardware interrupts off (there is nothing xenomai can do
>>> about that), or it could be an SMI issue. What about using the driver
>>> for the real graphic card you have ? Probably intel card? Do you observe
>>> any big latencies if you stress the system with anything else than X?
>>>
>>>> Power management options (ACPUI, APM): Disable ACPI (Advanced
>>>> Configuration and Power Interface) Support --> Processor Disable CPU
>>>> Frequency Scaling Disable CPU idle PM support Disable Power Managment
>>>> Support
>>> Disabling ACPI is a bad idea. As repeated many times, only
>>> ACPI_PROCESSOR should be disabled, not ACPI.
>>>
>>
>> Thanks for your helpful responses.
>>
>> I'm not working on this project again until next week, but on Friday I was
>> able
>> to
>>
>> o Recompile the kernel with ACPI enabled
>> o Boot with the 'SMI handler' BIOS option set to disabled....
>> according to the help text this option should be disabled if 'an RTOS
>> is installed' - I presume this means that SMIs are completely disabled
>> and therefore SMIs cannot be the source of the problem
>> (very convenient BIOS option... now I begin to appreciate the expense of
>> this
>> board!)
>> o Changed xorg to use the intel video driver
>
> Now you can try NoAccel with the intel video driver too....
>
>
> --
> Gilles.
>
ipipe_trace
Description: Binary data
_______________________________________________ Xenomai-help mailing list Xenomai-help@gna.org https://mail.gna.org/listinfo/xenomai-help
