[Mesa-users] Gallium llvmpipe driver not using multiple cores on Windows

[Brian Paul]

On 04/11/2014 05:26 PM, Steve Darnell wrote:
> Greetings,
>
> I am using the cross-compilation instructions from the QT project to
> build the Gallium llvmpipe software driver for Windows (Mesa 10.0.4,
> LLVM 3.4, x86):
> http://qt-project.org/wiki/Cross-compiling-Mesa-for-Windows
> <https://urldefense.proofpoint.com/v1/url?u=http://qt-project.org/wiki/Cross-compiling-Mesa-for-Windows&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=lGQMzzTgII0I7jefp2FHq7WtZ%2BTLs8wadB%2BiIj9xpBY%3D%0A&m=ujsd3oD%2BWws4ESg5PhR%2FfUj7TxGag8CK9hfXC5pkH1I%3D%0A&s=257b6bbb850a39649c078a113871e36a33f1971340fbd7dccc056f206c91bb3b>.
> I am building on Linux Mint 14 (based on Ubuntu 12.10). The purpose is
> to replace the Microsoft OpenGL software drive with the Mesa version
> when my program is used in a Remote Desktop (RDP) session.
>
> The build is successful and the resulting driver renders my graphics
> properly. However, I noticed that only one CPU thread is used by my
> program for OpenGL rendering rather than using my eight available CPU
> threads (my processor is an Intel Core i7 Sandybridge processor with
> four hyperthreaded cores). I am hoping that this is a simple build
> configuration issue; however, I have been unsuccessful identifying a
> solution.
>
> Has anyone experienced this issue or have some suggestions to try? The
> script I am using for the build process is copied below.

I've never actually tried llvmpipe on Windows, but there's an env var to 
tell llvmpipe how many threads to use: LP_NUM_THREADS

Ex: "export LP_NUM_THREADS=4".

Or you could go in with a debugger and check the value of 
util_cpu_caps.nr_cpus

-Brian