Need reviewer: jmap -permstat

[Martin Buchholz]

On Tue, Jul 29, 2008 at 3:51 PM, Daniel D. Daugherty
<Daniel.Daugherty at sun.com> wrote:
> This patch should be done in the following repository:
>
>   http://hg.openjdk.java.net/jdk7/hotspot-svc/hotspot

That's what we thought as well, but that forest had not been kept up to date.
But I now see that it has been recently updated.
Is that due to a recent change in procedure?

Certainly we can push this change to hotspot-svc.
I doubt there is concurrent ongoing work in PermStat.java.

Who is the hotspot-svc gatekeeper?

Martin

> Dan
>
>
> Hiroshi Yamauchi wrote:
>>
>> Hi,
>>
>> I'd like to contribute this patch. I need a reviewer who is familiar
>> with the Hotspot Serviceability Agent.
>>
>> The description of the patch is something like:
>>
>>        Accounting for more memory uses associated with class metadata
>>        in PermGen which "jmap -permstat" misses.
>>
>> In a small test, the "jmap -permstat" command reports only about
>> 50-60% of the permgen memory usage (compared to the actual usage of
>> permgen based on what the "jmap" command reports). This patch will
>> increase the number up to 80-90%.
>>
>> Martin Buchholz did an initial review for me and he is volunteering to
>> be the committer.
>>
>> Here's the patch which is based on a very recent version of
>> http://hg.openjdk.java.net/jdk7/jdk7
>>
>> --- a/agent/src/share/classes/sun/jvm/hotspot/tools/PermStat.java
>> +++ b/agent/src/share/classes/sun/jvm/hotspot/tools/PermStat.java
>> @@ -266,45 +266,51 @@
>>       out.println();
>>    }
>>
>> +   private static long objectSize(Oop oop) {
>> +      return oop == null ? 0L : oop.getObjectSize();
>> +   }
>> +
>> +   // Don't count the shared empty arrays
>> +   private static long arraySize(Array arr) {
>> +     return arr.getLength() != 0L ? arr.getObjectSize() : 0L;
>> +   }
>> +
>>    private long computeSize(InstanceKlass k) {
>>       long size = 0L;
>> -      // InstanceKlass object size
>> +      // the InstanceKlass object itself
>>       size += k.getObjectSize();
>>
>> -      // add ConstantPool size
>> -      size += k.getConstants().getObjectSize();
>> +      // Constant pool
>> +      ConstantPool cp = k.getConstants();
>> +      size += cp.getObjectSize();
>> +      size += objectSize(cp.getCache());
>> +      size += objectSize(cp.getTags());
>>
>> -      // add ConstantPoolCache, if any
>> -      ConstantPoolCache cpCache = k.getConstants().getCache();
>> -      if (cpCache != null) {
>> -         size += cpCache.getObjectSize();
>> +      // Interfaces
>> +      size += arraySize(k.getLocalInterfaces());
>> +      size += arraySize(k.getTransitiveInterfaces());
>> +
>> +      // Inner classes
>> +      size += objectSize(k.getInnerClasses());
>> +
>> +      // Fields
>> +      size += objectSize(k.getFields());
>> +
>> +      // Methods
>> +      ObjArray methods = k.getMethods();
>> +      int nmethods = (int) methods.getLength();
>> +      if (nmethods != 0L) {
>> +         size += methods.getObjectSize();
>> +         for (int i = 0; i < nmethods; ++i) {
>> +            Method m = (Method) methods.getObjAt(i);
>> +            size += m.getObjectSize();
>> +            size += objectSize(m.getConstMethod());
>> +         }
>>       }
>>
>> -      // add interfaces size
>> -      ObjArray interfaces = k.getLocalInterfaces();
>> -      size +=  (interfaces.getLength() != 0L)? interfaces.getObjectSize()
>> : 0L;
>> -      ObjArray transitiveInterfaces = k.getTransitiveInterfaces();
>> -      size += (transitiveInterfaces.getLength() != 0L)?
>> transitiveInterfaces.getObjectSize() : 0L;
>> -
>> -      // add inner classes size
>> -      TypeArray innerClasses = k.getInnerClasses();
>> -      size += innerClasses.getObjectSize();
>> -
>> -      // add fields size
>> -      size += k.getFields().getObjectSize();
>> -
>> -      // add methods size
>> -      ObjArray methods = k.getMethods();
>> -      size += (methods.getLength() != 0L)? methods.getObjectSize() : 0L;
>> -      TypeArray methodOrdering = k.getMethodOrdering();
>> -      size += (methodOrdering.getLength() != 0L)?
>> methodOrdering.getObjectSize() : 0;
>> -
>> -      // add each method's size
>> -      int numMethods = (int) methods.getLength();
>> -      for (int i = 0; i < numMethods; i++) {
>> -         Method m = (Method) methods.getObjAt(i);
>> -         size += m.getObjectSize();
>> -      }
>> +      // MethodOrdering - an int array that records the original
>> +      // ordering of methods in the class file
>> +      size += arraySize(k.getMethodOrdering());
>>
>>       return size;
>>    }
>>
>> I'd appreciate it if someone at Sun can sponsor this.
>>
>> Thanks,
>> Hiroshi
>>
>