Speeding up GC

[law@redhat.com]

 In message <20020604.075504.56053777.davem@redhat.com>, "David S. Miller" 
writes:
 > Remember in your answer to my question that the precondition is that
 > mprotect and the like are not considered fast.  :-)
True.  However, if we use it wisely it may still be helpful.  For example, if
we have a large number of of objects that are not expected to ever change
and they have good locality, we could use the VM system to help us identify
when they do change (and which in turn would cause us to examine them in the
collecting pass).

 > I am of the opinion that people are in general too lazy about how they
 > allocate RTL objects when they make changes to the compiler middle and
 > back ends.  This is why we have this enormous problem today.
Agreed.

jeff