Can anybody help me around this weird phenomena ?

I wrote a Conjugate-gradient library for solving linear algebraic systems of equations, I use LU factorization, so in the residuals updating step, I need to perform a triangular matrix solve twice, however, the analysis step (cusparseDcsrsv_analysis) of the triangular solver takes alot of time ! for instance, if the whole solver is to need 360 ms to converge, these two lines of analysis would need 330 ms of them !

```
cusparseMatDescr_t descrL = 0 ;
cusparseMatDescr_t descrU = 0 ;
cusparseStatus = cusparseCreateMatDescr(&descrL) ;
cusparseStatus = cusparseCreateMatDescr(&descrU) ;
cusparseSetMatType(descrL,CUSPARSE_MATRIX_TYPE_TRIANGULAR) ;
cusparseSetMatIndexBase(descrL,CUSPARSE_INDEX_BASE_ONE) ;
cusparseSetMatDiagType(descrL,CUSPARSE_DIAG_TYPE_UNIT) ;
cusparseSetMatFillMode(descrL,CUSPARSE_FILL_MODE_LOWER) ;
cusparseSetMatType(descrU,CUSPARSE_MATRIX_TYPE_TRIANGULAR) ;
cusparseSetMatIndexBase(descrU,CUSPARSE_INDEX_BASE_ONE) ;
cusparseSetMatDiagType(descrU,CUSPARSE_DIAG_TYPE_NON_UNIT) ;
cusparseSetMatFillMode(descrU,CUSPARSE_FILL_MODE_UPPER) ;
cusparseSolveAnalysisInfo_t inforL = 0 ;
cusparseSolveAnalysisInfo_t inforU = 0 ;
cusparseStatus = cusparseCreateSolveAnalysisInfo(&inforL) ;
cusparseStatus = cusparseCreateSolveAnalysisInfo(&inforU) ;
startSP = omp_get_wtime() ;
cusparseStatus = cusparseDcsrsv_analysis(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, NZLT, descrL, matrixLT, iRowLT, jColLT, inforL) ;
if(cusparseStatus != CUSPARSE_STATUS_SUCCESS) printf("%s \n\n","cusparseDcsrsv_analysis1 Error !") ;
cusparseStatus = cusparseDcsrsv_analysis(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, NZUT, descrU, matrixUT, iRowUT, jColUT, inforU) ;
if(cusparseStatus != CUSPARSE_STATUS_SUCCESS) printf("%s \n\n","cusparseDcsrsv_analysis2 Error !") ;
finishSP = omp_get_wtime() ;
cusparseStatus = cusparseDcsrsv_solve(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, &c2, descrL, matrixLT, iRowLT, jColLT, inforL, r, t) ;
if(cusparseStatus != CUSPARSE_STATUS_SUCCESS) printf("%s \n\n","cusparseDcsrsv_solve1 Error !") ;
cusparseStatus = cusparseDcsrsv_solve(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, &c2, descrU, matrixUT, iRowUT, jColUT, inforU, t, z) ;
if(cusparseStatus != CUSPARSE_STATUS_SUCCESS) printf("%s \n\n","cusparseDcsrsv_solve2 Error !") ;
```

I appreciate your help very much, Thanks in advance.