[Mesa-dev] static version of osmesa is missing llvm symbols, bug?

[Emil Velikov]

On 12/03/14 00:08, Burlen Loring wrote:
> yep, I'm using 10.1.0 and also noticed the same in 9.2.2.
>
In that case "it wasn't me" ;-)

> in short static linking is essential for reasonable performance of
> parallel applications on Cray systems. In this scenario the application
> is duplicated across 100s/1000s of compute nodes which share a
> remote-parallel file system (Lustre/GPFS). As a dynamically linked
> application starts, shared library loading hit's the file system hard.
> However, Cray suggests users run static linked executables. Their
> application launcher bypasses the file system and copies statically
> linked executable directly into a ram fs onto the set of compute nodes
> that a given job is scheduled to run on. This avoids file system
> contention that would be introduced by a parallel application's shared
> library loading.
>
> I maintain and support ParaView and interactive OpenGL based rendering
> application on NERSC's Crays. Given that this is an interactive
> application, having a reasonable startup time is important. Users have
> complained and I've observed times when using shared libraries when app
> startup takes more than 30 min! if we build fully static executable
> startup time is reduced to seconds.
>
> For me statically linked mesa is important, which is why I want to
> report this. Without OSMesa we can't use these systems, and the new
> llvmpipe OSMesa state tracker has been really awesome, allowing us to do
> things we couldn't in the past without GPUs. I hope that you don't
> discontinue static link support.
>
Had some additional patches that cleans up mesa's build a bit further 
but I guess I'll bring back (classic and gallium) static osmesa first. 
Especially considering the numbers you've quoted.

> We have experienced some segfaults in llvmpipe OSMesa in the static
> linked version (bt shows SEGV at
> create_jit_texture_type.isra.1 at draw_llvm.c:128). If I can reproduce this
> off the Cray I will file a bug report. Thought I'd mention in case you
> can confirm that there is a known issue with the static link.
>
AFAIK static linking with llvm is a bit of a hit and miss. For that 
reason mesa 10.2 may be building against shared llvm. Then again I do 
not work on that part of mesa, so take this with a pinch of salt.

Brian Paul is the only person that I've seen working/bug fixing osmesa 
so I'm guessing that he'll take a look in due time. Meanwhile it may be 
worth filing bug report(s) for these two boogers :-)


Cheers,
Emil

> Thanks
> Burlen
>
> On 03/11/2014 03:13 PM, Emil Velikov wrote:
>> On 11/03/14 20:31, Burlen Loring wrote:
>>> Hi All,
>>>
>> Hi Burlen
>>
>>> When I make a static build of mesa with osmesa+llvm, all of the llvm
>>> related symbols are undefined in the resulting libOSMesa.a archive.
>>> There is an "la" file produced that lists the dependencies, however
>>> shouldn't those all be linked into the installed archive? for reference
>>> see my configure line below.
>>>
>> Earlier today I have pushed a patch [1] for mesa that completely
>> disabled static building for all of mesa.
>>
>> While that may not be the reason for the problem you're seeing (afaics
>> you're using mesa 10.1.0 and my patch just made it into master) it
>> would be great if you can let us know what the your use case of
>> static  OSMesa is, so that we can evaluate the situation.
>>
>>
>> Many thanks
>> Emil
>>
>> P.S. With the commit [1] --enable-static --disable-shared will produce
>> an warning message and will fall back to --disable-static
>> --enable-shared.
>>
>> [1]
>> http://cgit.freedesktop.org/mesa/mesa/commit/?id=a6efbac9fb502c4f0166e7a0680b6828e1f6926c
>>
>>
>>> Burlen
>>>
>>>
>>> Mesa-10.1.0$make distclean; autoreconf -fi; ./configure CXXFLAGS="-O2 -g
>>> -fPIC -DDEFAULT_SOFTWARE_DEPTH_BITS=31" CFLAGS="-O2 -g -fPIC
>>> -DDEFAULT_SOFTWARE_DEPTH_BITS=31" --enable-static=yes --enable-shared=no
>>> --disable-xvmc --disable-glx --disable-dri --with-dri-drivers=
>>> --with-gallium-drivers=swrast --enable-texture-float
>>> --disable-shared-glapi --disable-egl --with-egl-platforms=
>>> --enable-gallium-osmesa --enable-gallium-llvm=yes
>>> --with-llvm-prefix=/work/apps/llvm/3.2/
>>> --prefix=/work/apps/mesa-10.1.0-a && make -j2 && make -j4 install
>>> _______________________________________________
>>> mesa-dev mailing list
>>> mesa-dev at lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>