I just want to know where and how /run/lock
and /run/shm
can help our PC .
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 56G 13G 41G 24% /
udev 983M 4.0K 983M 1% /dev
tmpfs 396M 840K 395M 1% /run
none 5.0M 8.0K 5.0M 1% /run/lock
none 990M 164K 990M 0% /run/shm