"Charles M. Hannum" wrote:

> > Using the patch I posted, uvm_pagedeactivate() does not require or
> > imply any penalty.  If another process is using the data, then the
> > referenced bit will get set, and it will get reactivated.
>
> False.  The faults and/or system calls that cause the deactivates are
> asynchronous WRT the pagedaemon, and can (will?) easily cause the
> pages to get paged out more often.  (Note that, since the inactive
> scan happens first, so this is *particularly* like -- e.g. if the one
> process then went and allocated another page, implicitly kicking the
> pagedaemon.)  There is a really trivial test case that causes this to
> behave very, very badly.
>
> > What reference count?  On the page?  Pages don't have a reference
> > count.
>
> That's true, but the object holding the page (e.g. the anon) does have
> a reference count that could potentially be used.

No, thats a diffrent story as I know...