PS 5.5.28 mysql server swapping even when 4-5G memory is available


I 'm seeing couple of mysql db master swapping and using 3-4G of swap memory , but strangely db server has 4-5G free RAM available.

Any idea why mysql is using swap when server has enough ram .

Swappiness is set to 0 on these server .

[db1 ~]$ free -g
total used free shared buffers cached
Mem: 125 122 3 0 0 10
-/+ buffers/cache: 111 14
Swap: 15 4 11

how all memory/buffer parameter configured in my.cnf file? if possible paste your mysql config here.
check what other application/process running on this server except mysql and get top 10 memory utilized process.

[B]You’re assuming that MySQL is causing swapping. Check your system’s swappiness setting.

Some further reading on this; [/B]

my.cnf is using standard config as all other db servers in our environment (for same system config) .Swappiness is set to 0 .

Please paste here the result of:
numactl --hardware
ps aux --sort=rss |tail