On Mon, 2016-04-11 at 22:23 +0200, Jesper Dangaard Brouer wrote: > If we have a page-pool recycle facility, then we could use the trick, > right? (As we know that get_page_unless_zero() cannot happen for pages > in the pool).
Well, if you disable everything that possibly use get_page_unless_zero(), I guess this could work. But then, you'll have to spy lkml traffic forever to make sure no new feature is added in the kernel, using this get_page_unless_zero() in a new clever way. You could use a page flag so that z BUG() triggers if get_page_unless_zero() is attempted on one of your precious pages ;)\ We had very subtle issues before my fixes (check 35b7a1915aa33da812074744647db0d9262a555c and children), so I would not waste time on the lock prefix avoidance at this point.
