Shared memory not enabled in 2.4.0?

For some reason shared memory is not being enabled on my system running kernel
v2.4.0 (on RedHat v6.2,  with all updates applied).

Per the documentation I have this line in my /etc/fstab:

     none  /dev/shm  shm defaults  0 0

Yes, I have created this subdirectory:

     # ls -l /dev | grep shm
     drwxrwxrwt    1 root     root            0 Jan  7 11:54 shm

No complaints are seen at startup, yet I still have no shared memory:

     # cat /proc/meminfo
             total:    used:    free:  shared: buffers:  cached:
     Mem:  130293760 123133952  7159808        0 30371840 15179776
     Swap: 136241152        0 136241152
     MemTotal:       127240 kB
     MemFree:          6992 kB
     MemShared:           0 kB
     Buffers:         29660 kB
     Cached:          14824 kB
     Active:           3400 kB
     Inact_dirty:     37872 kB
     Inact_clean:      3212 kB
     Inact_target:        4 kB
     HighTotal:           0 kB
     HighFree:            0 kB
     LowTotal:       127240 kB
     LowFree:          6992 kB
     SwapTotal:      133048 kB
     SwapFree:       133048 kB

Is there some configuration option which I missed?  Some trick not mentioned in
the doc?

Thank you.