TNS-12518: TNS:listener could not hand off client connection

The listener was went down at when load was high and it didn't turn on automatically (my environment is RAC)

TNS-12518: TNS:listener could not hand off client connection
TNS-12571: TNS:packet writer failure
TNS-12560: TNS:protocol adapter error
TNS-00530: Protocol adapter error
Linux Error: 104: Connection reset by peer

[oracle@myoracle admin]$ cat /var/log/messages
cat: /var/log/messages: Permission denied

as per “Oracle” issue seems to be due to “Extensive paging/swapping activity is a clear indication that the sytem is running out of the physical memory” and solutions offered as below

1. Increase the physical memory of the system or
[oracle@myoracle OPatch]$ free
total used free shared buffers cached
Mem: 32960108 31415136 1544972 0 870980 21807352
-/+ buffers/cache: 8736804 24223304
Swap: 16777200 366380 16410820

2. Apply the Patch 6139856 for unpublished Bug 6139856 if available for your platform or
[oracle@myoracle OPatch]$ ./opatch lsinventory | grep 6139856
[oracle@myoracle OPatch]$

3. Configure Hugepages on the OS. Ref : Note 361323.1
[oracle@myoracle OPatch]$ grep Hugepagesize /proc/meminfo
Hugepagesize: 2048 kB

Ref: TNS Listener Crash with Core dump [ID 549932.1]
HugePages on Linux: What It Is... and What It Is Not... [ID 361323.1]