No shared spaces configured

Heap
garbage-first heap   total 6291456K, used 1368757K [0x0000000640000000, 0x00000007c0000000, 0x00000007c0000000)
  region size 2048K, 97 young (198656K), 9 survivors (18432K)
compacting perm gen  total 1048576K, used 230859K [0x00000007c0000000, 0x0000000800000000, 0x0000000800000000)
   the space 1048576K,  22% used [0x00000007c0000000, 0x00000007ce172e10, 0x00000007ce173000, 0x0000000800000000)
No shared spaces configured.

this was seen in a

java/jdk170_91-64b/bin/java -XX:-UseBiasedLocking -XX:SurvivorRatio=10 -verbose:gc -XX:+PrintGCTimeStamps -Xms6144m -Xmx6144m -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=1024m -XX:MaxPermSize=1024m  -XX:+UseG1GC -XX:InitiatingHeapOccupancyPercent=60 

I am not really sure what this "No shared spaces configured" would mean - I could not find any decent documentation on this message. And it doesn't seem to be really an error message, nor something related to G1GC...