-XX:+UseLargePages giving failed to reserve shared memory warning

[shwelzen]

Hi,

Can someone provide any inputs / suggestions for using Large Memory Pages?

Total RAM available is 15 GB.

Heap is set to 6 GB

Perm is set to 6 GB

Huge Page Size: 2048 KB

Different values for Total No of Huge Pages were also set using: echo [page total] > /proc/sys/vm/nr_hugepages

But, still getting below warning, even though performance increased a bit after setting the parameter.

Please help resolve.

JAVA_OPTS:  -server -XX:+UseCompressedOops -XX:+TieredCompilation -Xms6000m -Xmx6000m -XX:PermSize=6000m -XX:MaxPermSize=6000m -XX:ReservedCodeCacheSize=256m -XX:+UseCodeCacheFlushing -XX:+UseLargePages -Djava.net.preferIPv4Stack=true -Dorg.jboss.resolver.warning=true -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true -Djboss.server.default.config=standalone.xml

=========================================================================

Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared memory (errno = 1).

Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared memory (errno = 22).

Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared memory (errno = 1).

Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared memory (errno = 1).

14:20:55,406 INFO  [org.jboss.modules] JBoss Modules version 1.1.1.GA

14:20:55,524 INFO  [org.jboss.msc] JBoss MSC version 1.0.2.GA

14:20:55,560 INFO  [org.jboss.as] JBAS015899: JBoss AS 7.1.1.Final "Brontes" starting

14:20:56,088 INFO  [org.xnio] XNIO Version 3.0.3.GA

14:20:56,088 INFO  [org.jboss.as.server] JBAS015888: Creating http management service using socket-binding (management-http)

14:20:56,098 INFO  [org.xnio.nio] XNIO NIO Implementation Version 3.0.3.GA

14:20:56,107 INFO  [org.jboss.remoting] JBoss Remoting version 3.2.3.GA

14:20:56,115 INFO  [org.jboss.as.logging] JBAS011502: Removing bootstrap log handlers

Thanks,

Sheldon

[fharms]

"reserve shared memory (errno = 22)" typical mean you trying to access more huge pages you have reserved or the application don't have access to them.

Remember to give the user access to call the memlock system calls in /etc/security/limits.conf

I found this guide very useful when enable huge pages http://andrigoss.blogspot.dk/2008/02/jvm-performance-tuning.html

Do you really need a permGen of 6 GB?

/Flemming

[shwelzen]

Hi Flemming,

Thanks for the response.

Actually, we do need a large Heap and Perm Size as the application server should be able to support more than 5k users and some applications use a large amount of memory.

Once we resume Performance Testing the applications on JBoss, we will make the configuration changes and get back to you incase of any warning / errors.

Thanks,

Sheldon