© Thomas Kunz 2000
SCE 574
250
Design Issues
for Paging Systems
äThe
working-set model
äAllocation
of page frames
äPaging
daemons
äA
background process that periodically inspects memory looking for pages to evict
based on the page replacement algorithm
äThe
contents of the page may be remembered in case the page is needed again before it
gets overwritten
äLocking
pages
äA
page is locked in memory to prevent its replacement.
äPage
locks are needed to allow I/O operations to complete before the page to which I/O is
being done gets replaced
äAn
alternative is to use system buffers to do I/O.
äPage
sharing
äPage
size