*Created by: mhoemmen* @trilinos/tpetra @vbrunini In most cases, `Tpetra::MultiVector`'s host View is the result of `Kokkos::create_mirror_view` on its device View. However, in one case: https://github.com/trilinos/Trilinos/blob/5c9a2ec8019b310b5b74a22e23fcbea11486f781/packages/tpetra/core/src/Tpetra_MultiVector_def.hpp#L427 Tpetra creates the host View from the input device View using `Kokkos::create_mirror`. This means that, unlike in all other cases, the host View is always a separate allocation (even if not building with CUDA!) from the device View. That's weird, and it may be causing issues relating to my fixes for #4626. Note the comment above that line of code: ``` // The difference between create_mirror and create_mirror_view, is // that the latter copies to host. We don't necessarily want to // do that; we just want to allocate the memory. ``` `git blame` dates that to 2015. It could have been the case back then that `create_mirror_view` copied to host. It certainly does not now.