IBM WebSphere 6.1 JIT compiler options

[Kerry]

Due to a potential problem with optimizations carried out against our
code by the IBM J9 JIT compiler we are trying to take control of the
configuration of the JIT compiler using the guidance set forth in the
Diagnostics Guide,
http://publib.boulder.ibm.com/infocenter/javasdk/v5r0/topic/com.ibm.java.doc.diagnostics.50/diag/tools/jitpd_diagnose.html.

Some samples of options that work:

-Xjit:verbose,optLevel=hot,count=0,exclude={java/math/*}
-Xjit:{java/lang/*}(optLevel=warm,count=0)

The problem is, the documentation is vague and seemingly incomplete in
some respects. Specifically, we want to perform the following tasks:

1) Selectively enable custom optLevel and count for all methods in all
classes in a particular package (ex. java/math/*) while applying other
optLevel to all other classes.
2) Print verbose output when applying custom optLevel and count to
particular package.

For #1 I have tried various things (none of which work) including:

-Xjit:verbose,optLevel=hot,count=0{java/math/*}(optLevel=warm,count=0)
-Xjit:verbose,optLevel=hot,count=0,{java/math/*}
(optLevel=warm,count=0)

For #2 I have tried various things (none of which work) including:

-Xjit:verbose{java/math/*}(optLevel=warm,count=0)
-Xjit:verbose,{java/math/*}(optLevel=warm,count=0)
-Xjit:{java/math/*}(verbose,optLevel=warm,count=0)

Is it just not possible to do what I am trying to do? Is there any
better documentation on the IBM 5.0 JIT compiler? I am Googling and
not comping up with anything more detailed than the inadequete
documentation in teh Diagnostic Guide.

[matt....@empowermx.com]

Really apologize if this ends up as a double-post.

[matt....@empowermx.com]

One other thing I forgot to mention. We can't seem to find the proper parameter to increase the size of the code cache used by the JIT compiler. The Diagnostic Guide says to use

However, even after setting it like this

-Xcodecache256m

we get the following output indicating the cache size is still 32768 KB.

JIT type: Testarossa (Full)
JIT options specified:
verbose
options in effect:
bcount=250
catchSamplingSizeThreshold=1100
classLoadPhaseInterval=500
classLoadPhaseThreshold=155
code=32768 (KB)
codepad=0 (KB)
codetotal=0 (KB)
count=1000
counts=- - - - 1000 250 1000 500 - - 10000 10000
data=8192 (KB)
experimentalClassLoadPhaseInterval=40
hotFieldThreshold=10
interpreterSamplingDivisor=16
interpreterSamplingThreshold=300
iprofilerDialDownThreshold=500000
iprofilerJITSamplesBeforeTurningOff=40
iprofilerReactivateThreshold=1000000
iprofilerSamplesBeforeTurningOff=35000000
iprofilerSwitchThreshold=60
mtcount=-1
resetCountThreshold=4000
sampleInterval=30
sampleThreshold=3000
sampleThresholdVariationAllowance=30
samplingFrequency=10
samplingThreadExpirationTime=-1
scorchingSampleThreshold=240
softFailOnAssume
stack=1024
target=amd64-win
userClassLoadPhaseThreshold=5
verbose=1