Add the memory swappiness tuning option to docker.

Memory swappiness option takes 0-100, and helps to tune swappiness
behavior per container.
For example, When a lower value of swappiness is chosen
the container will see minimum major faults. When no value is
specified for memory-swappiness in docker UI, it is inherited from
parent cgroup. (generally 60 unless it is changed).

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Upstream-commit: 921da495d24695dda66d3f58e78887dd0bc2402e
Component: engine

components/engine/docs/reference/api/docker_remote_api_v1.20.md

@@ -160,6 +160,7 @@ Create a container
              "CpusetCpus": "0,1",
              "CpusetMems": "0,1",
              "BlkioWeight": 300,
+             "MemorySwappiness": 60,
              "OomKillDisable": false,
              "PortBindings": { "22/tcp": [{ "HostPort": "11022" }] },
              "PublishAllPorts": false,
@@ -208,6 +209,7 @@ Json Parameters:
 -   **CpusetCpus** - String value containing the `cgroups CpusetCpus` to use.
 -   **CpusetMems** - Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
 -   **BlkioWeight** - Block IO weight (relative weight) accepts a weight value between 10 and 1000.
+-   **MemorySwappiness** - Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.
 -   **OomKillDisable** - Boolean value, whether to disable OOM Killer for the container or not.
 -   **AttachStdin** - Boolean value, attaches to `stdin`.
 -   **AttachStdout** - Boolean value, attaches to `stdout`.