Oracle and IBM AIX 5.2 swapping and memory issues

Lately,
Jordan bank upgraded their ICBS banking software to Oracle 9i and
IDS9i. The Bank also moved from a decentralized to a centralized
system.
We were contracted to monitor and diagnose performance issues during the launching phase of the new system.
The IBM server was equipped with 32 GB of RAM, The Oracle SGA was
around 8GB of RAM. Around 2000 sessions were running on the system.
every now and then, high swapping activity was noticed, and the performance tended to degrade the longer the system is running.
The cause of this phenomenon is attributed to the AIX Virtual
Memory Manager. AIX keeps steeling memory pages to enhance the buffer
of File I/O. Since Oracle SGA is buffer file I/O already, such
Operating System feature is not suitable for Relational Database
Management Systems. Not only that, but SGA blocks end up being paged
from physical memory into paging, causing undesirable performance
impact.
The solution for this memory management problem configure memory
management in way that would decrease AIX physical memory acquisition
for buffering file IO.
The parameters that affect the described behaviour are shown in
bold below. Note that the shown values are the default values and are
not appropriate for RDBMS
memory_frames = 1572864
pinnable_frames = 1431781
maxfree = 1088
minfree = 960
minperm% = 20
minperm = 294356
maxperm% = 80
maxperm = 1177427
strict_maxperm = 0
maxpin% = 80
maxpin = 1258292
maxclient% = 80
lrubucket = 131072

It is recommended to modify the minperm% to 10-15%, maxperm% to 30% and maxclient% to value equal to maxpers% (30% in this case)
The following will enable you to find out how much memory is used by the AIX buffer system
# svmon -G
size inuse free pin virtual
memory 131072 128122 1800 10200 48990
pg space 262144 98220
work pers clnt lpage
pin 10203 0 0 0
in use 44030 84326 6