when the last process reference to a file goes away, the pages for
that file no longer count as "exec", but only as "file".  so pages
for /sbin/ttyflags pages will be reused pretty quickly.  if ttyflags
is run again, those pages count as "exec" while the program is running
and then turn back into "file" when it exits.

this mechanism could be thwarted by someone doing
"sleep 1000000000 < /sbin/ttyflags &" before running ttyflags,
but that doesn't seem very important.

-Chuck


On Tue, Dec 03, 2002 at 05:41:24PM +1100, matthew green wrote:
> 
> 
> could you also clarify [on tech-kern] the bit about (exec) pages
> in memory but not referenced?  i guess i'm thinking that i don't
> really want the system to cache my /sbin/ttyflags binary after
> it's run the one time it needs to be ....
> 
> 
> .mrg.