At 15:24 9/1/95 -0400, Jonathan Shapiro wrote:
>The piece I do not understand at the moment is the aging/checkpoint
>system. Both of these operations cause a potentially large number of
>objects to need to be written -- certainly more objects than there are
>likely to be I/O request descriptors. The question, then, is where is
>the list of objects that need to be written preserved?
Since KeyKOS does lazy page aging, it never ages beyond the available I/O descriptors. When it does checkpoint, it again stops its scan when it runs out of descriptors and restarts when some come available. This algorithm is probably not the most efficent, but it hasn't hurt too bad yet (ever?). The place that needs optimization is the object invocation path.
Bill Frantz Periwinkle -- Computer Consulting (408)356-8506 16345 Englewood Ave. frantz@netcom.com Los Gatos, CA 95032, USA