Re: [uml-user] threads in x86_64 UML

[Riccardo M. <ric...@gm...>]

Hi Richard,

On Thu, Jun 23, 2011 at 6:10 PM, richard -rw- weinberger
<ric...@gm...> wrote:
> On Thu, Jun 23, 2011 at 5:38 PM, Riccardo Murri
> <ric...@gm...> wrote:
>> I'm trying to run some MatLab compiled code in a x86_64 Debian squeeze UML;
>> unfortunately, the code crashes and the backtrace indicates that the problem is
>> due to a failing clone() call.
>
> UML had some problems with threads,
> but now every should work fine.
> Even on x86_64. :-)
>
> Where exactly does the code fail?
> Please provide us a stand-alone test case.
>

Being MatLab stuff, I'm afraid I cannot provide a full test case; this
is the top of the stack as it gets dumped out after the crash:

    [...]
    [ 13] 0x00000000452951c3
/mnt/dev/uml/matlab/MATLAB/MATLAB_Compiler_Runtime/v713/bin/glnxa64/../../bin/glnxa64/libmwservices.so+00668099
services::threading::ComputationalThreadsInit::ComputationalThreadsInit(bool)+000051
    [ 14] 0x0000000044fa38d3
/mnt/dev/uml/matlab/MATLAB/MATLAB_Compiler_Runtime/v713/bin/glnxa64/../../bin/glnxa64/libmwmcr.so+00129235
    [ 15] 0x0000000044fa3afb
/mnt/dev/uml/matlab/MATLAB/MATLAB_Compiler_Runtime/v713/bin/glnxa64/../../bin/glnxa64/libmwmcr.so+00129787
    [ 16] 0x00000000406f88ba
/lib/libpthread.so.0+00026810
    [ 17] 0x00000000409dd02d
/lib/libc.so.6+00847917 clone+000109

The code is running in the Debian 6 image from devloop.co.uk [1]
(no modifications save for installing a few X libraries required by
MatLab via apt-get) with the 2.6.39 kernel from the same site.

[1]: http://fs.devloop.org.uk/filesystems/Debian-Squeeze/Debian-Squeeze-AMD64-root_fs.bz2


> Does the program work in UML/i386?
>

Unfortunately I don't know: I currently only have access to the x86_64
MatLab compiler and libraries.

(For the record, the code runs fine on a physical machine and in
KVM-based virtual hosts, so it's really a UML issue.)

Thanks for your help!

Riccardo