RFR: 8284950: Swappiness disables swap space usage

[xpbob]

set memory.swappiness to 0,swap space will not be used 
determine the value of memory.swappiness
https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt


    Memory Limit: 50.00M
    Memory Soft Limit: Unlimited
    Memory & Swap Limit: 100.00M
    Maximum Processes Limit: 4194305 

=>

    Memory Limit: 50.00M
    Memory Soft Limit: Unlimited
    Memory & Swap Limit: 50.00M
    Maximum Processes Limit: 4194305

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Commit messages:
 - 8284950: Swappiness disables swap space usage

Changes: https://git.openjdk.java.net/jdk/pull/8285/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8285&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284950
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8285.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8285/head:pull/8285

PR: https://git.openjdk.java.net/jdk/pull/8285