             gp[I_q - 1 + ys] -= gupdate;
         }        
     }
-    //__syncthreads();
+    __syncthreads();
 
 
     /*     transverse-x

        }

    }
    //__syncthreads();


    /*  transverse-y

            fp[I_q] -= gupdate;
        }
    }
    __syncthreads();

    /*  transverse-y
    
