Permutation of a large sparse matrix

Hi,

What is the fastest way of permuting a large sparse_matrix_t in csr or csc format?

I could either do manual permutations on the csr arrays or I could create a sparse permutation matrix and use the mkl_sparse_spmm method.

Either method seems to be not optimal since I don't benefit from parallelism on the former method and I have to create additional arrays for the Permutation matrix and create a new copy of the matrix on the latter method.

Also, I notice that there might be performance differences between column and row permutations depending on whether the matrix is in csr or csc.

Is there a better way to do it?