How to resolve [WARNING] Forked JVM has been killed on time-out after 1800 seconds

After running several days nightly build of our smartgwt project, sometimes there will have a JVM killed issue caused by time out. If we restart our linux server, the issue will be resolved, but after serveral days nightly build, it will come up again.

Could you please help me to resolve this issue. Really appreciate for your suggestion on this.

1. Version
<gwt.version>2.5.1</gwt.version>
<gwt-maven-plugin.version>2.5.1</gwt-maven-plugin.version>
<smartgwt.version>4.0</smartgwt.version>

2. Pom fragment
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>${gwt-maven-plugin.version}</version>
<configuration>
<module>com.fusion.platform.gui.${env}</module>
<includes>**/GuiGwtTestSuite.java</includes>
<timeOut>1800</timeOut>
<testTimeOut>1800</testTimeOut>
<mode>htmlunit</mode>
<extraJvmArgs>-Xmx1024m -Xms1024m -Xss1024k</extraJvmArgs>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
</plugin>

3. Build failed info
[INFO] Compiling module com.fusion.platform.gui.PlatformGui
[INFO] Validating units:
[INFO] Ignored 258 units with compilation errors in first pass.
[INFO] Compile with -strict or with -logLevel set to TRACE or DEBUG to see all errors.
[INFO] Compiling 6 permutations
[INFO] Compiling permutation 0...
[INFO] Compiling permutation 3...
[INFO] Compiling permutation 4...
[INFO] Process output
[INFO] Compiling
[INFO] Compiling permutation 2...
[INFO] Compiling permutation 5...
[INFO] Process output
[INFO] Compiling
[INFO] Compiling permutation 1...
Process 1387262362712 is killed.
[WARNING] Forked JVM has been killed on time-out after 1800 seconds
[INFO]