PrintGCStats

[Naas, Dave]

Regarding the posting from Oct 26, 2007:  http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2007-October/000064.html	
where Mr. Kessler states: 
quote 
	> > I'll see if we can get an updated version of PrintGCStats out to replace the ancient one available at 
	> >	 <http://java.sun.com/developer/technicalArticles/Programming/turbo/> 
	> > That should give you the kinds of statistics you are asking for. 
	> > 	... peter 
unquote

I was wondering if a new version of PrintGCStats and PrintGCFixup will indeed be made available or if we should proceed with our own updates to handle new jdk releases, etc.??    

A specific, recent example is jdk 1.6 with the -XX:PrintFLSStatistics flag.  We have found that this setting prevents the current PrintGCStats from properly parsing ParNew data and thus doesn't generate the Promotion stats (Promo.csv file).   The following snippet shows how the ParNew line is now split (shown in bold), thanks to the -XX:PrintFLSStatistics:  

======================================================================================================================================================
{Heap before GC invocations=0 (full 0):
 par new generation   total 305088K, used 277376K [0x2f800000, 0x43d00000, 0x43d00000)
  eden space 277376K, 100% used [0x2f800000, 0x406e0000, 0x406e0000)
  from space 27712K,   0% used [0x406e0000, 0x406e0000, 0x421f0000)
  to   space 27712K,   0% used [0x421f0000, 0x421f0000, 0x43d00000)
 concurrent mark-sweep generation total 2739200K, used 0K [0x43d00000, 0xeb000000, 0xeb000000)
 concurrent-mark-sweep perm gen total 131072K, used 14913K [0xeb000000, 0xf3000000, 0xfb000000)
8.746: [GC Before GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 701235200
Max   Chunk Size: 701235200
Number of Blocks: 1
Av.  Block  Size: 701235200
Tree      Height: 1
Before GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 0
Max   Chunk Size: 0
Number of Blocks: 0
Tree      Height: 0
8.746: [ParNew
Desired survivor size 14188544 bytes, new threshold 1 (max 4)
- age   1:   15763640 bytes,   15763640 total
- age   2:         56 bytes,   15763696 total
: 277376K->15474K(305088K), 0.5657873 secs] 277376K->15474K(3044288K)After GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 701218816
Max   Chunk Size: 701218816
Number of Blocks: 1
Av.  Block  Size: 701218816
Tree      Height: 1
After GC:
Statistics for BinaryTreeDictionary:
------------------------------------
Total Free Space: 0
Max   Chunk Size: 0
Number of Blocks: 0
Tree      Height: 0
, 0.5668866 secs] [Times: user=0.34 sys=1.07, real=0.57 secs]
======================================================================================================================================================

Thank you, 
Dave 

 David Naas
Chicago Board Options Exchange 
 312-786-7222