[Networkit] RmatGenerator crashes

Christian Staudt christian.staudt at kit.edu
Tue Oct 27 23:27:35 CET 2015


True, I didn’t pay attention to that parameter. The generator works with more realistic inputs. What was strange is that high numbers crashed the interpreter immediately. I assume Graph G(n, true); fails with a segfault when n = 2^100 because a vector of this size cannot be allocated? But shouldn’t that raise an exception?

> and a quick look at the code suggest that there's something wrong the node ids of the drawn edges. I'll look into it.

Where do you see it?


On 27 Oct 2015, at 16:41, Maximilian Vogel <maximilian.vogel at student.kit.edu> wrote:

> Hi,
> You try to create a graph 2^100 nodes. That's quite a number. Still it shouldn't kill the kernel, but instead throw an exception or something. You might want to try a smaller number, then it should work.
> 
> The stack trace
> >>> generators.RmatGenerator(100, 3, 0.25, 0.25, 0.25, 0.25).generate()
> Program received signal SIGSEGV, Segmentation fault.
> 0x00007ffff58e4ca2 in std::vector<unsigned long, std::allocator<unsigned long> >::size (this=0x6bbdca0c771b9090) at /usr/include/c++/5.2.0/bits/stl_vector.h:655
> 655          { return size_type(this->_M_impl._M_finish - this->_M_impl._M_start); }
> (gdb) bt
> #0  0x00007ffff58e4ca2 in std::vector<unsigned long, std::allocator<unsigned long> >::size (this=0x6bbdca0c771b9090) at /usr/include/c++/5.2.0/bits/stl_vector.h:655
> #1  0x00007ffff590aae6 in NetworKit::Graph::indexInOutEdgeArray (this=0x7fffffffe010, u=8009626009359660960, v=11002897751786542239) at networkit/cpp/graph/Graph.cpp:187
> #2  0x00007ffff590e57a in NetworKit::Graph::increaseWeight (this=0x7fffffffe010, u=8009626009359660960, v=11002897751786542239, ew=1) at networkit/cpp/graph/Graph.cpp:820
> #3  0x00007ffff597f9d6 in NetworKit::RmatGenerator::generate (this=0x1c0c510) at networkit/cpp/generators/RmatGenerator.cpp:64
> #4  0x00007ffff58a3648 in __pyx_pf_10_NetworKit_13RmatGenerator_4generate (__pyx_v_self=<optimized out>) at networkit/_NetworKit.cpp:22097
> 
> and a quick look at the code suggest that there's something wrong the node ids of the drawn edges. I'll look into it.
> 
> Best,
> Max
> 
> On 27.10.2015 20:28, Christian Staudt wrote:
>> Hi all,
>> every time I tried to use the RmatGenerator it crashed, for example:
>> 
>> 	generators.RmatGenerator(100, 3, 0.25, 0.25, 0.25, 0.25).generate()
>> 
>> This kills the Python kernel for me. Any ideas why?
>> 
>> Chris
>> 
>> 
>> _______________________________________________
>> NetworKit mailing list
>> NetworKit at ira.uni-karlsruhe.de
>> https://lists.ira.uni-karlsruhe.de/mailman/listinfo/networkit
> 
> _______________________________________________
> NetworKit mailing list
> NetworKit at ira.uni-karlsruhe.de
> https://lists.ira.uni-karlsruhe.de/mailman/listinfo/networkit

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.ira.uni-karlsruhe.de/mailman/private/networkit/attachments/20151027/76d01855/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 495 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <https://lists.ira.uni-karlsruhe.de/mailman/private/networkit/attachments/20151027/76d01855/attachment.sig>


More information about the NetworKit mailing list