Method and apparatus for atomic file look-up. An atomic look-up operation (407) allows an application (405) to find out whether a file is opened atomically based on whether or not the file path is present in a file system namespace cache (406). If not, the file open request can be redirected, avoiding or minimizing impacts to the scheduling of various operations involved in executing an application. The request can be redirected by the application to a process that includes blocking point handling (408, 409). An operating system according to the present invention includes a file system (400) including a file system namespace (404), and an operating system kernel (402) is operatively connected to the file system (400). The operating system kernel includes the file system namespace cache and the atomic look-up operation.