This means that the Atom is doing a giant work.. and it is simply not able to handle it.
http://www.mesa3d.org/llvmpipe.htmlThe Gallium llvmpipe driver is a software rasterizer that uses LLVM to do runtime code generation. Shaders, point/line/triangle rasterization and vertex processing are implemented with LLVM IR which is translated to x86 or x86-64 machine code. Also, the driver is multithreaded to take advantage of multiple CPU cores (up to 8 at this time). It's the fastest software rasterizer for Mesa.
llvmpipe needs at least a multicore 64bit cpu to work well and a lot of profiling... it is not good for ARM or Atom. take a look at phoronix benchmarks.