Introduction

At work, I experienced an issue with JVM memory where Xmx and Xms were set to 4.5GB, and part of the memory was going to swap until a Full GC triggered, at which point the reserved memory (RSS) that had gone to swap returned to RAM.

The warning messages I received were:

  pages faults

I searched quite a bit before finding a solution.

Removing User Limitations

First, for the JVM, you need to add an option at launch:

  -XX+UseISM

This activates the use of Intimate Shared Memory.

However, users are limited under Solaris in terms of allocatable memory, so to increase the limit:

  projadd -U qa user.qa
projmod -sK "project.max-shm-memory=(privileged,64G,deny)" user.pmavro

Then log back in as user pmavro and verify that everything worked correctly:

  $ prctl -n project.max-shm-memory -i project user.pmavro
project: 100: user.pmavro
NAME    PRIVILEGE       VALUE    FLAG   ACTION                       RECIPIENT
project.max-shm-memory
       privileged      64,0GB      -   deny                                 -
       system          16,0EB    max   deny                                 -

Once this is done, the RES memory in the top command equals the maximum right from startup, and there are no more page fault issues. :-)

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Last updated 21 Oct 2008, 17:23 CEST. history