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Dear Martin<br>
<br>
I followed your suggestions<br>
<br>
<br>
Now we installed kernel 3.2.57-rt83 ( patch rt83 )<br>
<br>
<br>
Application runs at 1.5 Millisecond<br>
<br>
Now Priority of Ethercat-OP is 99 and application is 80<br>
<br>
with FIFO Scheduler<br>
<br>
<br>
Working counter sometimes is still from 139/139 to 0/139<br>
<br>
And with ethercat debug 1 .... show a couple of dumped frames<br>
<br>
it may happen every 20 minutes but it's occasional...<br>
<br>
may not happen for an hour or 2<br>
<br>
<br>
I saw in your email you use 3.10.x series...<br>
<br>
Would it have best performance in this case ?<br>
<br>
<br>
<br>
This command :<br>
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charset=ISO-8859-1">
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">$
NETDEVNAME=eth1</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">>$
ethtool --coalesce $NETDEVNAME adaptive-rx off
adaptive-tx off
rx-usecs 0 rx-frames 0 rx-usecs-irq 0 rx-frames-irq 0
tx-usecs 0
tx-frames 0 tx-usecs-irq 0 tx-frames-irq 0 pkt-rate-low
0
pkt-rate-high 0<br>
</span></b></font></font><br>
</p>
<br>
gives this output :<br>
<br>
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charset=ISO-8859-1">
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">adaptive-rx
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">adaptive-tx
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">pkt-rate-low
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">pkt-rate-high
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">rx-frames
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">rx-usecs-irq
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">rx-frames-irq
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">tx-usecs
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">tx-frames
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">tx-usecs-irq
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><font color="#000000"><font
style="font-size: 11pt" size="2"><b><span style="background:
#ffffff">tx-frames-irq
unmodified, ignoring
</span></b></font></font></p>
<p style="margin-bottom: 0cm" lang="it-IT"><br>
</p>
<p style="margin-bottom: 0cm" lang="it-IT">any other things I can
try ?<br>
</p>
<p style="margin-bottom: 0cm" lang="it-IT"><br>
Thank you very much...<br>
</p>
<p style="margin-bottom: 0cm" lang="it-IT"><br>
Best Regards<br>
</p>
<p style="margin-bottom: 0cm" lang="it-IT">Pier<br>
</p>
<br>
<br>
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<br>
On 11/04/14 09:32, Martin Troxler wrote:<br>
</div>
<blockquote cite="mid:53479AA0.3000601@komaxgroup.com" type="cite">
<pre wrap="">Hi Pier,
On 10.04.2014 14:12, pier wrote:
</pre>
<blockquote type="cite">
<pre wrap="">What you write works only with the realtime kernel... ?
</pre>
</blockquote>
<pre wrap="">No, but you will certainly discover other latency effects.
</pre>
<blockquote type="cite">
<pre wrap="">
We are using the Standard Ubuntu Kernel
The application runs under a Software Interrupt at 1.5 or 2 milliseconds...
we measured that it may have around 100 microseconds variation... ( Do you call it Jitter ? )
</pre>
</blockquote>
<pre wrap="">For how long did you run cyclictest and with what cpu/disk load? For tips see
<a class="moz-txt-link-freetext" href="https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO">https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO</a>
I am certain that you will get latencies > 10ms sooner or later with a "normal" kernel.
</pre>
<blockquote type="cite">
<pre wrap="">
So this is ok for our control application....
</pre>
</blockquote>
<pre wrap="">Our app runs with 4kHz.
</pre>
<blockquote type="cite">
<pre wrap="">
I did not know that the realtime kernel it's a must for etherlab...
</pre>
</blockquote>
<pre wrap="">It is not a must. But your realtime task will not run smooth.
</pre>
<blockquote type="cite">
<pre wrap="">
When sometimes ago I tried to use the Realtime kernel from the Ubuntu Repository
the size of the video screen was limited to 1024*768 and we cannot use the 1920*1080
screen resolution for the Graphic Application and Video that we have.
Also there was another restriction that now I do not recall now....
</pre>
</blockquote>
<pre wrap="">We use Ubuntu 12.04 LTS as you do, but with our own kernel (3.6 or 3.10 at the moment) built from sources and it works
as with the default Ubuntu kernel
</pre>
<blockquote type="cite">
<pre wrap="">
Do you think that the : Working counter changed to 0/113
( that may happens once every 2 or 3 hours )
</pre>
</blockquote>
<pre wrap="">Ok. That's not very often.
</pre>
<blockquote type="cite">
<pre wrap="">
it's because we use the standard kernel ?
</pre>
</blockquote>
<pre wrap="">Probably.
</pre>
<blockquote type="cite">
<pre wrap="">
Is the realtime kernel the only solution ?
</pre>
</blockquote>
<pre wrap="">I would give it a try.
</pre>
<blockquote type="cite">
<pre wrap="">
</pre>
</blockquote>
<pre wrap="">Regards
Martin
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</blockquote>
<br>
<br>
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