$ perl -MLinux::Smaps -le '$sm = Linux::Smaps->new($$); \
   sub psize { $sm->update; print $sm->size; }  \
   psize(); require POSIX; psize(); POSIX->import; psize();'
6312
6560
7088

##</code><code>##

$ perl -MGTop -le '$gtop = GTop->new; \
   sub psize { print $gtop->proc_mem($$)->size; } \
   psize(); require POSIX; psize(); POSIX->import; psize();'
7839744
7958528
8499200