Early page space allocation

If you want to ensure that a process will not be killed due to low paging conditions, this process can preallocate paging space by using the early page space allocation policy.

This is done by setting an environment variable called PSALLOC to the value of early. This can be done from within the process or at the command line (PSALLOC=early command). When the process uses the malloc() subroutine to allocate memory, this memory will now have paging-space disk blocks reserved for this process, that is, they are reserved for this process so that there is a guarantee that if the process needed to page out, there will always be paging space slots available for it. If using early policy and if CPU savings is a concern, you may want to set another environment variable called NODISCLAIM=true so that each free() subroutine call does not also result in a disclaim() system call.