[Haskell-cafe] how do FFI calls show up in profiling info?

Dear Cafe, how would FFI calls show up in profiles? I am using hmatrix-glpk. The relevant FFI call is in https://hackage.haskell.org/package/hmatrix-glpk-0.19.0.0/docs/src/Numeric.L... I am compiling with profiling (for executables and libraries), and I am running with +RTS -P . The .prof file does not contain c_simplex_sparse (the C function) It does mention simplexSparse (the Haskell function that calls it) but with a suspiciously low time. - J.W.