Thanks, understood. However file-backed pages such as executables and shared libs are not written to swap space as the pages are just dropped and read back in f

Thanks, understood. However file-backed pages such as executables and shared libs are not written to swap space as the pages are just dropped and read back in from the regular(non-swap) filesystem no? Not that causes any less disk I/O of course but they are not anonymous pages which is generally what is written to swap. When I think swap I think of "written to swap" but maybe you mean swap in the general sense of paged out?