C-heap memory leak of IceTea

[Andrew Haley]

On 12/19/2010 02:59 AM, Zhu Han wrote:
> Hi,
>
> I might observe C-heap leak of IcedTea6 1.9.2 on Ubuntu 10.04. This bug was
> reported against cassandra[1]. But I'm afraid it is a general openJDK
> problem. Here is the symptoms. [1] may has more information on it.
>
> For a infrequently accessed openJDK node, the memory usage is climbed up
> every day, and I'm pretty sure it is not caused by leak on Java object heap.
> This is the GC settings:
>
> " /usr/bin/java -ea -Xms1G -Xmx1G -XX:+UseParNewGC -XX:+UseConcMarkSweepGC
> -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1
> -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly
> -XX:+HeapDumpOnOutOfMemoryError ..."
>
> So the size of JVM heap is constant. Use pmap against the JVM process for
> the last 3 days, I observed a region expanded every day. It can be expanded
> to multiple gigabytes finally[1].
>
> on 12/19: 00000000010c3000 178548K rw---    [ anon ]
> on 12/18: 00000000010c3000 110320K rw---    [ anon ]
> on 12/17: 00000000010c3000  39256K rw---    [ anon ]
>
> I notice the region is on lower address of process address space. So I
> suspect it is the c-heap of JVM. The map of object heap is as below, which
> is constant in the last few days.
>
> 00002b58433c0000 1069824K rw---    [ anon ]
>
> Both the heap and non-heap memory usage of java code is quite normal:
>
> 12/19/2010 10:56:13 +0800 org.archive.jmx.Client HeapMemoryUsage:
> committed: 1065025536
> init: 1073741824
> max: 1065025536
> used: 160743000
>
> 12/19/2010 10:56:23 +0800 org.archive.jmx.Client NonHeapMemoryUsage:
> committed: 24313856
> init: 24313856
> max: 224395264
> used: 20477424
>
>
> There are hundreds of alive threads in the JVM.
>
> 12/19/2010 10:52:20 +0800 org.archive.jmx.Client PeakThreadCount: 244
>
>
>   Originally, I suspect it is bug 6824570[2]. But After I upgraded JDK from
> IceTea 1.8.2 to IceTea 1.9.2, the problem is still not fixed. [3] said it is
> fixed in IceTea 1.9.0.
>
> And there is another JVM instances running on the same node with ParNewGC
> enabled, I did not observe the memory leak.  Although the peak thread count
> is quite low of that instance, which is 43.
>
> Do you have any hints to diagnostic this problem? I'd like to help.

This may, of course, be a leak in JNI code.  What Java program was running?

Andrew.