The warning message in db2diag.log file 'Unable to determine swap space info' ECF=0x90000002=-1879048190=ECF_FAILED is seen in function stmmCalcMinMaxFree.
The following warning message will be seen repeated every 3 minutes in the db2diag.log
2010-01-27-13.37.00.307961-300 I2035400A547 LEVEL: Warning
PID : 2232360 TID : 7172 PROC : db2sysc 0
INSTANCE: DB2INST1 NODE : 000 DB : SAMPLE
APPHDL : 0-388 APPID: *LOCAL.DB2.100127164259
AUTHID : DB2INST1
EDUID : 7172 EDUNAME: db2stmm (SAMPLE) 0
FUNCTION: DB2 UDB, Self tuning memory manager, stmmCalcMinMaxFree,
MESSAGE : ECF=0x90000002=-1879048190=ECF_FAILED
DATA #1 : String, 36 bytes
Unable to determine swap space info.
DB2 uses the AIX function perfstat_memory_total() which is located inside libperfstat.a library to return various information about memory usage in the system including swap space size information. However in AIX 5.3 TL09 this function has been modified and DB2 V9.5 fixpack 5 was compiled to reflect those changes.
If DB2 V9.5 Fixpack 5 is run on an AIX level lower than 5.3 TL09 these warning messages will be seen in the db2diag.log because DB2 is calling an outdated AIX perfstat_memory_total() function
Resolving the problem
Update your current AIX 5.3 level to TL09 and above to ensure that your fileset bos.perf.libperfstat version is greater than or equal to 188.8.131.52 when running DB2 V9.5 Fixpack 5.