<font size=2 face="sans-serif">Thank you for your prompt attention! I
believe it is close to trunk stable; I did my build from the recommended
stable sources on February 1, so if there have been relevant changes I
guess I should rebuild and retry.</font>
<br>
<br><font size=2 face="sans-serif">In the meantime I have started a solve
with multithreading disabled, to see if it makes a difference; I might
have an answer in the morning.</font>
<br>
<br><font size=2 face="sans-serif">I will send the MPS just to you to avoid
spamming the list.</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">From:</font>
<td><font size=1 face="sans-serif">John Forrest <john.forrest@fastercoin.com></font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">To:</font>
<td><font size=1 face="sans-serif">cbc@list.coin-or.org</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Date:</font>
<td><font size=1 face="sans-serif">03/08/2013 04:33 PM</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Subject:</font>
<td><font size=1 face="sans-serif">Re: [Cbc] Cbc segfault after many hours
of CPU time</font></table>
<br>
<hr noshade>
<br>
<br>
<br><font size=3>I will take a look at it. Trunk stable ??<br>
<br>
John Forrest<br>
<br>
On 08/03/13 20:45, </font><a href=mailto:acw@ascent.com><font size=3 color=blue><u>acw@ascent.com</u></font></a><font size=3>
wrote:</font>
<br><font size=2 face="sans-serif">I have a model which I have been trying
to solve thus:</font><font size=3> <br>
</font><font size=2 face="sans-serif"><br>
> ./cbc -threads 4 -import trouble.mps -solve -quit</font><font size=3>
<br>
</font><font size=2 face="sans-serif"><br>
As you can see, the only even slightly exotic thing I'm doing is enabling
multithreading, which has worked fine for me with less-challenging models.</font><font size=3>
<br>
</font><font size=2 face="sans-serif"><br>
Cbc works on this for several hours and then segfaults. I tried it
three times. On two occasions, it did about 5.5 M nodes before dying
(taking about half a CPU-day, but only three or four hours of wallclock
time). On the third occasion, it managed more than 27 M nodes and
2.5 CPU-days (but only overnight by the wall clock).</font><font size=3>
<br>
</font><font size=2 face="sans-serif"><br>
On all occasions, the number of nodes on the tree rises rapidly to about
93 K, then remains approximately constant (within a few hundred) for the
rest of the ill-fated run.</font><font size=3> <br>
</font><font size=2 face="sans-serif"><br>
Has anyone else had similar experiences?</font><font size=3> <br>
</font><font size=2 face="sans-serif"><br>
I have not yet tried running the model without multithreading, for obvious
practical reasons: it would probably take twelve hours if I was lucky,
and might take sixty.</font><font size=3> <br>
</font><font size=2 face="sans-serif"><br>
I'll be glad to share the MPS file (about a quarter of a meg uncompressed)
with anybody who wants to try this.</font><font size=3> <br>
</font>
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