Checking The Cpu Usage Ratio - Hitachi CE50-10 Instruction Manual

5. Configuring Software Environment
5.17 Checking the CPU usage ratio
Use the vmstat command to check the CPU usage ratio for the unit.
Run the command in the following format.
$ vmstat measurement-period(unit: second) measurement-count
Execution example:
$ vmstat 10 3
The following shows an example of output of the command.
The values in the first record (on the first line) indicate the average values from the time the OS starts to the time the
command is run. The values in the second and subsequent records indicate the average values between measurement
periods. In the execution example, the values in the second and subsequent records are the average values for the latest
10 seconds.
The sum of the values of us and sy indicates the CPU usage ratio. For example, the first record in the output example
indicates that the CPU usage ratio from the time the OS started to the time the command was run is 17 + 3 = 20%.
For details about each item, see Table 5-22.
Table 5‒22: List of items displayed by the vmstat command
Item
r Number of processes that are running or that are in the executable state
b Number of processes that are in an uninterruptable sleep state
swpd
Virtual memory size being used
free Available memory size
buff Memory size being used as the buffer
cache Memory size being used as the cache
si Size of memory that is written back from a disk as a swap (per second)
so
Size of memory that is written to a disk as a swap (per second)
bi Read size from a block device (per second)
bo Write size to a block device (per second)
in Number of interruptions (per second)
cs Number of times context switching occurs (per second)
us
Ratio of the execution time of a user process (other than the kernel code)
sy Ratio of the execution time of the system (kernel code)
id Ratio of the idle time during which the CPU is not used (= 100% - us - sy - wa -st)
wa Ratio of the I/O wait time
st Ratio of the time for which usage is restricted by the virtual machine
For the CE50-10, 0 is always displayed.
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Meaning