FFT segmentation violation

ROOT
1

Hello,
I am running
ROOT 5.20/00 (tags/v5-20-00@24532, Sep 23 2008, 17:12:35 on linuxx8664gcc)
on ubuntu hardy heron.
The configuration is the following:

[code]export ROOTSYS=/usr/local/root

./configure linuxx8664gcc --enable-soversion --enable-python --enable-gsl-shared --enable-shared --enable-fftw3 --with-fftw3-incdir=/usr/local --with-fftw3-libdir=/usr/lib

export ROOTSYS=/usr/local/root
export PATH=$ROOTSYS/bin:$PATH
export LD_LIBRARY_PATH=$ROOTSYS/lib:$LD_LIBRARY_PATH[/code]

I have installed the ubuntu fft packages:
fftw3, libfftw3-3, libfftw3-dev

These packages have version 3.1.2-2ubuntu2 (fftw3) and 3.1.2-3ubuntu1 (libfftw3-3 and libfftw3-dev).

When running the tutorial FFT.C, I am running into a segmentation violation when executing the line

[quote]*** Break *** segmentation violation
Attaching to program: /proc/16453/exe, process 16453
[Thread debugging using libthread_db enabled]
[New Thread 0x2b56e27f54d0 (LWP 16453)]
0x00002b56e22f74a5 in waitpid () from /lib/libc.so.6
error detected on stdin
The program is running. Quit anyway (and detach it)? (y or n) [answered Y; input not from terminal]
Detaching from program: /proc/16453/exe, process 16453
Root > Function FFT() busy flag cleared[/quote]

In gdb,
I get the following backtrace:

[quote]Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x2b9a65511370 (LWP 16486)]
0x0000000000000000 in ?? ()
(gdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x00002b9a68dae256 in TFFTRealComplex::TFFTRealComplex () from /usr/local/root/lib/libFFTW.so
#2 0x00002b9a68db7f52 in G__G__FFTW_104_0_4 () from /usr/local/root/lib/libFFTW.so
#3 0x00002b9a6023c400 in Cint::G__CallFunc::Execute () from /usr/local/root/lib/libCint.so.5.20
#4 0x00002b9a5fa35851 in TCint::CallFunc_ExecInt () from /usr/local/root/lib/libCore.so.5.20
#5 0x00002b9a5fa2ccbb in TMethodCall::Execute () from /usr/local/root/lib/libCore.so.5.20
#6 0x00002b9a5f9ad4d7 in TPluginHandler::ExecPlugin () from /usr/local/root/lib/libCore.so.5.20
#7 0x00002b9a5f9f121c in TVirtualFFT::FFT () from /usr/local/root/lib/libCore.so.5.20
#8 0x00002b9a6156fced in TH1::FFT () from /usr/local/root/lib/libHist.so.5.20
#9 0x0000000000402e39 in main (argc=1, argv=0x7fff4b4dd688) at meinfft.cc:70
(gdb) [/quote]

I don’t know what is happening and would be glad if anyone could help me.

2

Hi,

As the first step, could you make sure that fftw is installed correctly by running some of their internal tests, without ROOT involved?

Cheers,
Anna

3

I would like to do that.
Just tried to run the bench thing in the examples subdirectory.
Doesn’t compile, a whole file is missing.
Do you know any test I could run, post the code?
Bye, Bjoern

4

Hi Bjoern,

I’d say, that if you can’t compile bench, it’s a bad sign, and it probably doesn’t make sense to try other tests. I have installed from source, and, to be honest, I have no idea how the ubuntu packages work and what could go wrong in that part. I’ll try to ask the experts.

Anna

5

Hi Bjørn,

(I assume the ‘oe’ is really ‘ø’ :slight_smile:

I’m a little puzzled why you have

and

That is, you point to the headers in /usr/local, while you point at headers in /usr/lib. That seems inconsistent. I think you should point at headers in /usr/include instead. Debian (and by extension Ubuntu) packages should never install in /usr/local.

Also, why have you installed the package fftw3? It’s most likely a transitional dummy package and should be harmless though.

Don’t expect to be able to build the bench.c program - some headers are missing.

I ran the FFT.C script through my ROOT installation (5.19/05) with no problems.

I think you should recheck your build. If you still have problems, rebuild ROOT with debugging symbols (configure option –build=debug) and run the script in ROOT via GDB to get more information.

Sorry I couldn’t do more for you.

Yours,

6

Thanks for all the comments.
You were right with the wrong includedirs; but I did try to compile root without fftw flags, which should work, because ubuntu’s fftw is installed in /usr/include and /usr/lib.
I solved the problem by manually downloading fftw3 and installing in /usr/local/include and /usr/local/lib, and then linking root against these directories.
FFT works now.