Add the option BUILD_MULTITHREADING to CMAKE, only enabled on APPLE and MSVC platforms. This controls multi-core (BulletMultiThreaded), MiniCL, DX11 and OpenCL acceleration.

On other platforms (Linux) it might work, but it is unsupported.
Fix some warnings in btBulletWorldImprter

Demos/AllBulletDemos/CMakeLists.txt

@@ -25,7 +25,7 @@ ${VECTOR_MATH_INCLUDE}
 )
 
 LINK_LIBRARIES(
-GLUI  GIMPACTUtils HACD ConvexDecomposition BulletMultiThreaded OpenGLSupport  BulletWorldImporter BulletSoftBody BulletDynamics BulletCollision BulletFileLoader LinearMath ${GLUT_glut_LIBRARY} ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
+GLUI  GIMPACTUtils HACD ConvexDecomposition  OpenGLSupport  BulletWorldImporter BulletSoftBody BulletDynamics BulletCollision BulletFileLoader LinearMath ${GLUT_glut_LIBRARY} ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
 )
 
 SET(AllBulletDemos_SRCS

Demos/CMakeLists.txt

@@ -1,5 +1,5 @@
 
-IF (USE_DX11)
+IF (USE_DX11 AND BUILD_MULTITHREADING)
 	SUBDIRS(DX11ClothDemo)
 ENDIF()
 
@@ -10,31 +10,34 @@ IF (USE_GLUT)
 	IF (GLUT_FOUND)
 		IF(BUILD_CPU_DEMOS)
 			SET(SharedDemoSubdirs
-			OpenGL AllBulletDemos  ConvexDecompositionDemo
-			CcdPhysicsDemo BulletXmlImportDemo ConstraintDemo SliderConstraintDemo GenericJointDemo Raytracer
-			RagdollDemo ForkLiftDemo BasicDemo RollingFrictionDemo RaytestDemo VoronoiFractureDemo GyroscopicDemo FractureDemo Box2dDemo BspDemo MovingConcaveDemo VehicleDemo
-			UserCollisionAlgorithm CharacterDemo SoftDemo 
-			CollisionInterfaceDemo ConcaveConvexcastDemo SimplexDemo DynamicControlDemo
-			ConvexHullDistance
-			DoublePrecisionDemo ConcaveDemo CollisionDemo
-			ContinuousConvexCollision ConcaveRaycastDemo GjkConvexCastDemo
-			MultiMaterialDemo SerializeDemo InternalEdgeDemo 
-			MultiThreadedDemo
-			ParticlesOpenCL
-			OpenCLClothDemo
+				OpenGL AllBulletDemos  ConvexDecompositionDemo
+				CcdPhysicsDemo BulletXmlImportDemo ConstraintDemo SliderConstraintDemo GenericJointDemo Raytracer
+				RagdollDemo ForkLiftDemo BasicDemo RollingFrictionDemo RaytestDemo VoronoiFractureDemo 
+				GyroscopicDemo FractureDemo Box2dDemo BspDemo MovingConcaveDemo VehicleDemo
+				UserCollisionAlgorithm CharacterDemo SoftDemo 
+				CollisionInterfaceDemo ConcaveConvexcastDemo SimplexDemo DynamicControlDemo
+				ConvexHullDistance
+				DoublePrecisionDemo ConcaveDemo CollisionDemo
+				ContinuousConvexCollision ConcaveRaycastDemo GjkConvexCastDemo
+				MultiMaterialDemo SerializeDemo InternalEdgeDemo 
 			)
 		ELSE()
-			SET(SharedDemoSubdirs
-			OpenGL
-		)
-		ENDIF()
+			SET(SharedDemoSubdirs			OpenGL		)
+		ENDIF(BUILD_CPU_DEMOS)
+		
+		IF(BUILD_MULTITHREADING)
+			SUBDIRS(	MultiThreadedDemo			ParticlesOpenCL			OpenCLClothDemo			)
+		ENDIF(BUILD_MULTITHREADING)
 
 		SUBDIRS( 		
 			${SharedDemoSubdirs}
 			Benchmarks
-			ThreadingDemo
-			VectorAdd_OpenCL
 		)
+		
+		IF(BUILD_MULTITHREADING)
+			SUBDIRS(	ThreadingDemo		VectorAdd_OpenCL )
+		ENDIF()
+
 	ENDIF(GLUT_FOUND)
 ELSE (USE_GLUT)
 	IF (WIN32)

Demos/OpenCLClothDemo/CMakeLists.txt

@@ -1,4 +1,4 @@
-	SUBDIRS( MiniCL  )
+SUBDIRS( MiniCL  )
 
 IF(BUILD_INTEL_OPENCL_DEMOS)
 	SUBDIRS(Intel)

Demos/SerializeDemo/CMakeLists.txt

@@ -11,7 +11,7 @@ SET(GLUT_ROOT ${BULLET_PHYSICS_SOURCE_DIR}/Glut)
 # You shouldn't have to modify anything below this line 
 ########################################################
 
-IF(BUILD_AMD_OPENCL_DEMOS)
+IF(BUILD_AMD_OPENCL_DEMOS AND BUILD_MULTITHREADING)
 	SUBDIRS(AMD)
 ENDIF()