dlopen-ing a library with OpenMP by a non-OpenMP process

[Kostik Belousov]

On Wed, Nov 12, 2008 at 01:09:22PM -0500, Mikhail Teterin wrote:
> Hello!
> 
> Currently, when a program built without OpenMP (-fopenmp) is trying to 
> dlopen a library, built with the feature, the result is a crash from 
> "bad system call":
> 
>    #0  0x00000008009a223c in ksem_init () from /lib/libc.so.7
>    #1  0x0000000800998a8f in sem_init () from /lib/libc.so.7
>    #2  0x00000008011a6537 in omp_get_nested () from /usr/lib/libgomp.so.1
>    #3  0x00000008011a3466 in ?? () from /usr/lib/libgomp.so.1
>    #4  0x0000000000000002 in ?? ()
>    #5  0x00000008005072b2 in dlsym () from /libexec/ld-elf.so.1
>    #6  0x0000000800507cd2 in dlopen () from /libexec/ld-elf.so.1
>    ...
> 
> Can anything be done about this -- disable the OpenMP functionality, but 
> keep the library usable (single-threaded)? The problem arises, in 
> particular, when one is trying to use libraries built by either 
> GraphicsMagick or ImageMagick ports. Both have an OpenMP option, which 
> speeds up some internal algorithms. The option is off by default, but 
> enabling it makes sense on an SMP system... Yet, this makes the library 
> unsuitable for other purposes... Thanks! Yours,
> 
>    -mi
> 
> P.S. I'm seeing the crash on a recent FreeBSD-7.1/amd64, but it, likely, 
> can be seen elsewhere.

Try "kldload sem".
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20081112/62fb2f76/attachment.pgp