Merge pull request fluent#15 from nokute78/update_mem

in_mem:update example and add information about swap

input/mem.md

@@ -1,22 +1,23 @@
 # Memory Usage
 
-The __mem__ input plugin, gathers the information about the memory usage of the running system every certain interval of time and reports the total amount of memory and the amount of free available.
+The __mem__ input plugin, gathers the information about the memory and swap usage of the running system every certain interval of time and reports the total amount of memory and the amount of free available.
 
 ## Getting Started
 
-In order to get memory usage from your system, you can run the plugin from the command line or through the configuration file:
+In order to get memory and swap usage from your system, you can run the plugin from the command line or through the configuration file:
 
 ### Command Line
 
 ```bash
-$ bin/fluent-bit -i mem -t memory -o stdout -m '*'
-Fluent-Bit v0.8.0
+$ fluent-bit -i mem -t memory -o stdout -m '*'
+Fluent-Bit v0.11.0
 Copyright (C) Treasure Data
 
-[0] memory: [1463544745, {"total"=>8081140, "free"=>2548704}]
-[1] memory: [1463544746, {"total"=>8081140, "free"=>2560020}]
-[2] memory: [1463544747, {"total"=>8081140, "free"=>2559616}]
-[3] memory: [1463544748, {"total"=>8081140, "free"=>2559568}]
+[2017/03/03 21:12:35] [ info] [engine] started
+[0] memory: [1488543156, {"Mem.total"=>1016044, "Mem.used"=>841388, "Mem.free"=>174656, "Swap.total"=>2064380, "Swap.used"=>139888, "Swap.free"=>1924492}]
+[1] memory: [1488543157, {"Mem.total"=>1016044, "Mem.used"=>841420, "Mem.free"=>174624, "Swap.total"=>2064380, "Swap.used"=>139888, "Swap.free"=>1924492}]
+[2] memory: [1488543158, {"Mem.total"=>1016044, "Mem.used"=>841420, "Mem.free"=>174624, "Swap.total"=>2064380, "Swap.used"=>139888, "Swap.free"=>1924492}]
+[3] memory: [1488543159, {"Mem.total"=>1016044, "Mem.used"=>841420, "Mem.free"=>174624, "Swap.total"=>2064380, "Swap.used"=>139888, "Swap.free"=>1924492}]
 ```
 
 ### Configuration File