On Wed, 2006-09-13 at 10:45 -0400, Rik van Riel wrote: > > But another trouble you have not mentioned is what happens to pages > > with pending make-volatile that need to and/or have been made stable > > in the meantime. They too need to be removed from this pending list. > > At the time where you walk the set of pages (pagevec?) to make > volatile, you can check whether the page flags are still right. A make volatile can be done anytime as long as the page is in page cache. Before a page can be made stable the caller needs to make sure that one of the conditions that prevent a make volatile becomes true. So a page in the pending make-volatile array does not have to be removed because a make stable has been done. It only has to be removed if it gets freed. > A page that was set to be marked volatile with the hypervisor, > but later turned stable again would have that indicated in its > page flags, right? Several page flag bits and some other conditions like "has a mapping" and "reference count is map count + 1". Most of the checks that need to be done for make volatile are on page flags. -- blue skies, Martin. Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH "Reality continues to ruin my life." - Calvin.
