On Tue, Apr 10, 2018 at 12:45:56PM -0500, Christopher Lameter wrote:
> On Tue, 10 Apr 2018, Matthew Wilcox wrote:
> > > How do you envision dealing with the SLAB_TYPESAFE_BY_RCU slab caches?
> > > Those must have a defined state of the objects at all times and a
> > > constructor is
> > > required for that. And their use of RCU is required for numerous lockless
> > > lookup algorithms in the kernhel.
> > Not at all times. Only once they've been used. Re-constructing them
> > once they've been used might break the rcu typesafety, I suppose ...
> > would need to examine the callers.
> Objects can be freed and reused and still be accessed from code that
> thinks the object is the old and not the new object....
Yes, I know, that's the point of RCU typesafety. My point is that an
object *which has never been used* can't be accessed. So you don't *need*