Another one I categorize under 'I should write this down before I forget'.

Connor Mcdonald - Oracle geek and entertainer extraordinaire - shared this with me last week. Apparently, he was having some memory issues after upgrading to 11gR2 under AIX. As we run 80% of our databases under AIX, I thought I should make a mental note about it (some may call it a blogentry).

For those with metalink access - lookup note id ID 1246995.1 titled 'Memory footprint for dedicated server processes more than doubled after 11g upgrade on AIX platform'.

 

The symptoms are :

• excessive memory utilization for dedicated server process after upgrade to 11.2.0.1 or 11.2.0.2 on AIX
• svmon on oracle OS process id shows size of USLA, User-Space Loader Assistant, heap of about 7M bytes

 

 

Example 

svmon -P <PID>

outputs

• 11.2.0.1.0 -> 7M bytes (=USLA x 4k page size)
• 11.1.0.7.0 -> 60KB 
• 10.2.0.4.0 -> 420KB

 svmon -P 1368120 | grep USLA

 10e811d  9fffffff clnt USLA text,/dev/hd2:8227      s     17     0    -       -

 10d89b9  80020014 work USLA heap                   sm      0     0 1895    1895 ---> x4K = 7Mb

 

Example on 11.2.0.1 (patched)

  c291c2  80020014 work USLA heap                   sm     31     0    0      31 ---> x4K = 124K

 

 

 

This is apparently a bug

Bug 10211065.-P Base Bug 9796810

Abstract: MEMORY FOOTPRINT FOR DEDICATED SERVER PROCESSES MORE THAN DOUBLED AFTER 11G UGP

 

 

Bug 9796810.-P Base Bug 10190759

Abstract: 11G SERVER PROCESSES CONSUMING MUCH MORE MEMORY THAT 10G OR 9I

 

 

Bug 10190759.-P

Abstract:  PROCESSES CONSUMING ADDITIONAL MEMORY DUE TO 'USLA HEAP'

 

 

The good news is - there's a 'interim' patch - number 10190759.

It basically changes the make file so that it excludes certain options (-bexpfull and -brtllib) related to 11g's online patching feature.

It's not really an Oracle problem but it seems related to a bug in runtime loader on AIX.