When running this small test program I get a huge
C-heap footprint of > 1.5 GB on Solaris AMD. Only in -server mode.
In -client mode or on Linux the C-heap is down to < 50m.
The Java heap behaves normally in all cases. Just a few MB
is being allocated. Check with pmap:

08070000 65488K rwx-- [ heap ] <- -client
08070000 1637480K rwx-- [ heap ] <- -server


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import java.nio.ByteBuffer;

public class TestDirectBuffer
{
        public static void main( String args[] ) throws Exception
        {
                for ( int i = 0; i < 1024*1024*5; i++ )
                {
                        ByteBuffer.allocateDirect( 128 );
                }

                while ( true )
                {
                        Thread.currentThread().sleep( 500 );
                }
        }
}
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