Review request for 6857194

[mandy.chung]

Karen, Keith,

I add several new perf counters to collect time spent in various aspects
about class loading.

Webrev:
  http://cr.openjdk.java.net/~mchung/6857194/webrev.00/

Changes:
1. Counters to collect the time spent in defineClass and the byte size
read.
2. Counters to collect the number of bytes read when parsing a class
file stream.
The existing sun.cls.loadedBytes and sharedLoadedBytes counter (in
classLoadingService.cpp - that was carried from 1.4.2) represent the
footprint of a instanceKlass.  The new counters measure the numbers of
bytes in the classfile read.

3. Existing class init, class link, and class verify counters include
the class loading and resolution.  I add the counters to measure the
exclusive time (i.e. self time) as well.

I ran startup3 on Windows XP.  No significant overhead.
==============================================================================

mchung.baseline:
Benchmark           Samples        Mean     Stdev             Geomean
Weight
startup3                 15        2.36      0.04
==============================================================================

mchung.hsfix:
Benchmark           Samples        Mean     Stdev   %Diff     P  
Significant
startup3                 15        2.35      0.05    0.24
0.714            *
==============================================================================


Thanks
Mandy

[mandy.chung]

Keith,

Thanks for reviewing the first version.
    http://cr.openjdk.java.net/~mchung/6857194/webrev.01/

I made a fix in jvm.cpp line 759 that missed to name the variable in
webrev.00 and thus caused the small defineClass time. I also changed
parseClassFile to use the same solution as oops/instanceKlass.cpp using
the recursion_counter.

Here is the result of extracting from the perfdata of a few apps runs:
    http://cr.openjdk.java.net/~mchung/startup_measurement/perfdata.summary

Thanks
Mandy

Mandy Chung wrote:

> Karen, Keith,
>
> I add several new perf counters to collect time spent in various
> aspects about class loading.
>
> Webrev:
>  http://cr.openjdk.java.net/~mchung/6857194/webrev.00/
>
> Changes:
> 1. Counters to collect the time spent in defineClass and the byte size
> read.
> 2. Counters to collect the number of bytes read when parsing a class
> file stream.
> The existing sun.cls.loadedBytes and sharedLoadedBytes counter (in
> classLoadingService.cpp - that was carried from 1.4.2) represent the
> footprint of a instanceKlass.  The new counters measure the numbers of
> bytes in the classfile read.
>
> 3. Existing class init, class link, and class verify counters include
> the class loading and resolution.  I add the counters to measure the
> exclusive time (i.e. self time) as well.
>
> I ran startup3 on Windows XP.  No significant overhead.
> ==============================================================================
>
> mchung.baseline:
> Benchmark           Samples        Mean     Stdev             Geomean
> Weight
> startup3                 15        2.36      0.04
> ==============================================================================
>
> mchung.hsfix:
> Benchmark           Samples        Mean     Stdev   %Diff     P  
> Significant
> startup3                 15        2.35      0.05    0.24
> 0.714            *
> ==============================================================================
>
>
> Thanks
> Mandy