Kernel 2.4 seems to have deprecated the 'shared' statistic, and top/ps now
show zero for this value. IMHO, it would be best if they didn't show a
statistic that isn't being computed.
*** Bug 31719 has been marked as a duplicate of this bug. ***
we will keep displaying shared because many scripts are parsing the output of
/proc/meminfo or "free". Removing the statistic would break this.
At least, that's what Michael K Johnson, procps maintainer, told me.
Shared mem is computed again as of linux-2.4.6.