Modified Page List

From VSI OpenVMS Wiki
Jump to: navigation, search

The modified page list is the part of secondary page cache that contains pages allocated to the process that have been modified. It is controlled with the MPW* system parameters:

  • MPW_HILIMIT sets the upper limit for the modified page list.
  • MPW_IOLIMIT specifies the number of outstanding I/Os to the modified-page writer.
  • MPW_LOLIMIT sets the lower limit for the modified page list.
  • MPW_LOWAITLIMIT specifies the threshold at which processes in the miscellaneous wait state MPWBUSY are allowed to resume.
  • MPW_PRIO sets the priority of I/O transfers initiated by the modified page writer.
  • MPW_THRESH sets a lower bound of pages that must exist on the modified-page list before the swapper writes this list to acquire free pages.
  • MPW_WAITLIMIT sets the number of pages on the modified page list that causes a process to wait until the next time the modified page writer writes the modified list.
  • MPW_WRTCLUSTER sets the number of pages to be written during one I/O operation from the modified-page list to the page file or a section file.

See also