On Sun, May 13, 2007 at 10:46:30PM -0700, Andrew Morton wrote:

otoh, the intersection between pages which are PageBooked() and pages which
are PageLazyFree() should be zreo, so it'd be good to actually formalise
this reuse within the ext4 patches.

otoh2, PageLazyFree() could have reused PG_owner_priv_1.

Rik, Ted: any thoughts?  We do need to scrimp on page flags: when we
finally run out, we're screwed.

It makes sense to me.  PG_lazyfree is currently only in -mm, right?  I
don't see it in my git tree.  It would probably would be a good idea
to make sure that we check to add some sanity checking code if it
isn't there already that PG_lazyfree isn't already set when try to set
PG_lazyfree (just in case there is a bug in the future which causes
the should-never-happen case of trying lazy free a PageBooked page).

						- Ted