On Wed, 12 Apr 2017 06:18:29 +0000, Vernooij, Kees wrote: >The advantage of not freeing the aux slot was that a page could >be paged out without I/O if it had not been changed. Somewhat >the opposite op page reclaim. Freeing it after it has been changed >is of course a 100% useful reclaim of aux slots.
Yes, but that would require that someone periodically run through page frames looking for the change bit set, then looking to see if it is backed on AUX, and freeing it if it is. z/OS supports 4 TB of real storage. That's a billion pages to look at. How many CPU cycles is such a reclaim worth? -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
