Not so fast: it's possible to have library-level fault tolerance, or OS-level fault tolerance, that is implemented in software, without having to change the sou

Not so fast: it's possible to have library-level fault tolerance, or OS-level fault tolerance, that is implemented in software, without having to change the source code much or at all. My perspective on this is informed by work on ABFT (for more on that, see https://www.computer.org/csdl/trans/tc/1984/06/01676475.pdf https://www.computer.org/csdl/trans/tc/1984/06/01676475.pdf, and the literally 1000 later papers citing it) -- you can design a version of the basic linear algebra subroutines that have fault-tolerance built in, and use them without changing program source code. For codes that spend a lot of time doing numerical computations (e.g., preliminary data reduction in a spacecraft on-board computer), ABFT is an interesting option.