> write an application that uses MADV_SEQUENTIAL, expecting the VM system
    > to deactivate pages after you have looked at them and notice that this
    > does not appear to happen.  scratch head and read the source (mmm, source)
    > and realise that while the code does advice you can't change it.
   
   MADV_SEQUENTIAL doesn't do this.  SEQUENTIAL is intended to cause a clustered
   pagein of page N -> N + M (whatever a convenient cluster size is), so that
   faults aren't taken on the subsequent pages.


yes, it does this...but it also deactives pages behind -- if i'm going
to be sequentially accessing some memory, i don't need it after i have
read it, right?  this is what MADV_SEQUENTIAL does in NetBSD currently
except for the fact that you have no way to set it (other than Evil
Hacking :-).