In case you are getting this in the eclipse IDE, even after setting the parameters --launcher.XXMaxPermSize, -XX:MaxPermSize, etc, still if you are getting the same error, it most likely is that the eclipse is using a buggy version of JRE which would have been installed by some third party applications and set to default. These buggy versions do not pick up the PermSize parameters and so no matter whatever you set, you still keep getting these memory errors. So, in your eclipse.ini add the following parameters:

-vm <path to the right JRE directory>/<name of javaw executable>

还要确保将eclipse中的首选项中的默认JRE设置为正确的java版本。

1)增加永久内存大小

The first thing one can do is to make the size of the permanent generation heap space bigger. This cannot be done with the usual –Xms(set initial heap size) and –Xmx(set maximum heap size) JVM arguments, since as mentioned, the permanent generation heap space is entirely separate from the regular Java Heap space, and these arguments set the space for this regular Java heap space. However, there are similar arguments which can be used(at least with the Sun/OpenJDK jvms) to make the size of the permanent generation heap bigger:

 -XX:MaxPermSize=128m

默认为64m。

2)启用扫地功能

另一种方法是允许类被卸载，这样你的PermGen就永远不会用完:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled

这种方法在过去对我很有效。不过，有一件事是，使用这些有一个显著的性能权衡，因为永久扫描将像额外的2个请求，你发出的每一个请求或类似的东西。您需要在使用和权衡之间取得平衡。

您可以找到这个错误的详细信息。

http://faisalbhagat.blogspot.com/2014/09/java-outofmemoryerror-permgen.html

或者，你可以切换到JRockit，它处理permgen的方式不同于sun的jvm。它通常也有更好的性能。

http://www.oracle.com/technetwork/middleware/jrockit/overview/index.html

对于Sun JVM，使用命令行参数-XX:MaxPermSize=128m(显然是将128替换为您需要的任何大小)。

“他们”是错误的，因为我运行的是6.0.29，即使设置了所有选项也有同样的问题。正如蒂姆·豪兰所说，这些选择只会推迟不可避免的事情。它们允许我在遇到错误之前重新部署3次，而不是每次重新部署。

我有一个Hibernate+Eclipse RCP的组合，尝试使用-XX:MaxPermSize=512m和-XX:PermSize=512m，它似乎对我有用。