A computer-implemented method comprising: making a decision to swap out one or more pages from a working set of a process into a swap file; identifying one or more candidate pages for swapping from the working set of pages for the process; and reserving space in the swap file in secondary storage, the reserved space corresponding to a total size of the one or more candidate pages; characterized by : making a decision to write one or more of the identified candidate pages to the swap file, wherein the decision is made based on a determination that a threshold period of time has passed during which criteria that led to the decision to swap out are still valid; if the decision is made to write one or more of the identified candidate pages, removing the one or more candidate pages to be written from the working set and writing the one or more candidate pages to be written into sequentially ordered locations in the reserved space in the swap file, wherein the locations are reserved in virtual address order according to the virtual addresses of the candidate pages in the working set; and if the decision is made to not write one or more of the identified candidate pages, retaining the reserved locations until inswapping occurs. making a decision to swap out one or more pages from a working set of a process into a swap file; identifying one or more candidate pages for swapping from the working set of pages for the process; and reserving space in the swap file in secondary storage, the reserved space corresponding to a total size of the one or more candidate pages; characterized by : making a decision to write one or more of the identified candidate pages to the swap file, wherein the decision is made based on a determination that a threshold period of time has passed during which criteria that led to the decision to swap out are still valid; if the decision is made to write one or more of the identified candidate pages, removing the one or more candidate pages to be written from the working set and writing the one or more candidate pages to be written into sequentially ordered locations in the reserved space in the swap file, wherein the locations are reserved in virtual address order according to the virtual addresses of the candidate pages in the working set; and if the decision is made to not write one or more of the identified candidate pages, retaining the reserved locations until inswapping occurs. making a decision to write one or more of the identified candidate pages to the swap file, wherein the decision is made based on a determination that a threshold period of time has passed during which criteria that led to the decision to swap out are still valid; if the decision is made to write one or more of the identified candidate pages, removing the one or more candidate pages to be written from the working set and writing the one or more candidate pages to be written into sequentially ordered locations in the reserved space in the swap file, wherein the locations are reserved in virtual address order according to the virtual addresses of the candidate pages in the working set; and if the decision is made to not write one or more of the identified candidate pages, retaining the reserved locations until inswapping occurs. <EOS>