Fix occupancy calculation for grouped GEMM (#532)

test/unit/gemm/device/testbed_grouped.h

@@ -419,12 +419,6 @@ struct TestbedGrouped {
   /// Returns the number of threadblocks to launch if the kernel can run on the target
   /// device. Otherwise, returns zero.
   int sufficient() const {
-    //
-    // Determine SMEM requirements and waive if not satisfied
-    //
-
-    int smem_size = int(sizeof(typename Gemm::GemmKernel::SharedStorage));
-
     cudaDeviceProp properties;
     int device_idx;
     cudaError_t result = cudaGetDevice(&device_idx);
@@ -439,7 +433,7 @@ struct TestbedGrouped {
       throw std::runtime_error("cudaGetDeviceProperties() failed");
     }
 
-    int occupancy = std::min(2, int(properties.sharedMemPerMultiprocessor / smem_size));
+    int occupancy = Gemm::maximum_active_blocks();
 
     return properties.multiProcessorCount * occupancy;
   }