Embodiments are provided for isolating Input/Output (I/O) execution by combining compiler and Operating System (OS) techniques. The embodiments include dedicating selected cores, in multicore or many-core processors, as I/O execution cores, and applying compiler-based analysis to classify I/O regions of program source codes so that the OS can schedule such regions onto the designated I/O cores. During the compilation of a program source code, each I/O operation region of the program source code is identified. During the execution of the compiled program source code, each I/O operation region is scheduled for execution on a preselected I/O core. The other regions of the compiled program source code are scheduled for execution on other cores.