JVM crash due to perm gen space 99% in use問題

問題描述：

TransformerFactory tFactory = TransformerFactory. newInstance (); 
Transformer transformer = tFactory.newTransformer(new StreamSource(inputStream));
transformer.transform(xmlSource, outputTarget);//crash here

JAVA代碼中調用Transformer轉換xslt文件到xml文件時出現crash,crash 文件摘要：

Heap 
 def new generation   total 314560K, used 5786K [0x04600000, 0x19b50000, 0x19b50000) 
  eden space 279616K,   2% used [0x04600000, 0x04ba6b80, 0x15710000) 
  from space 34944K,   0% used [0x15710000, 0x15710000, 0x17930000) 
  to   space 34944K,   0% used [0x17930000, 0x17930000, 0x19b50000) 
 tenured generation   total 699072K, used 48833K [0x19b50000, 0x44600000, 0x44600000) 
   the space 699072K,   6% used [0x19b50000, 0x1cb005f0, 0x1cb00600, 0x44600000) 
 compacting perm gen  total 86272K, used 86136K [0x44600000, 0x49a40000, 0x64600000) 
   the space 86272K,  99% used [0x44600000, 0x49a1e2f8, 0x49a1e400, 0x49a40000) 
No shared spaces configured.

日志顯示perm gen空間不夠，轉換xslt確實需要load大量DLL文件，網絡上最多的解決方案就是增加JVM參數MaxPermSize值：

-XX:MaxPermSize=512M

按照這個方法逐漸加大幾次值後還是一直crash,而且發現一個有趣的現象：

compacting perm gen  total 86272K,

這個值一直沒有變化，為什麼？heap足夠大的情況下，JVM還沒有來得及增加perm gen就掛了？於是增加JVM參數直接初始化：

-XX:PermSize=512M

結果問題解決，看來這可能是JVM的bug，有空測測JRE7。

vm_info: Java HotSpot(TM) Client VM (20.4-b02) for windows-x86 JRE (1.6.0_29-b11), 
built on Oct  3 2011 01:01:08 by "java_re" with MS VC++ 7.1 (VS2003)