Comment 2 for bug 1623507

StacktraceTop:
 mir::fatal_error_abort(char const*, ...) (reason=0x7fe1e46e998c "Failed to schedule page flip") at ./src/common/fatal/fatal.cpp:43
 mir::graphics::mesa::DisplayBuffer::post() (this=0x5608093664b0) at ./src/platforms/mesa/server/kms/display_buffer.cpp:287
 mir::compositor::CompositingFunctor::operator()() (this=0x56080947b900) at ./src/server/compositor/multi_threaded_compositor.cpp:143
 operator() () at /usr/include/c++/6/functional:2136
 execute (this=0x7fe1de20cc70) at ./src/server/thread/basic_thread_pool.cpp:40