excessive VM_OUT_BYTES In Oracle 11g on Linux x86 64-bit

We are having a performance problem at the monent, and one of the things I have noticed in the AWR report is the high number for VM_OUT_BYTES and VM_IM_BYTES:
VM_IN_BYTES                           13,820,928
VM_OUT_BYTES                       1,589,587,968
PHYSICAL_MEMORY_BYTES    33,666,908,160

and When I query the following:
SQL> select * from V$OSSTAT ;

STAT_NAME                                                     VALUE  OSSTAT_ID
-------------------------------------------------- ---------------- ----------
COMMENTS                                                         CUM
---------------------------------------------------------------- ---
.....
VM_IN_BYTES                                           2194644201472       1009
Bytes paged in due to virtual memory swapping                    YES
VM_OUT_BYTES                                           784534494208       1010
Bytes paged out due to virtual memory swapping                   YES
...

Can someome tell me what exactly does this mean? and it the performance problem memory? We have 32gb on the server.