System Load or System Load Average
It is run-queue i.e a queue of processes waiting for a resource(cpu, i/o etc.) to become available .
Consider a single-core cpu
as a single lane of traffic with bridge and process as cars.
Now in this situation System load is
- 0.0 – If there is no traffic on the road.
- 1.0 -If the traffic on the road is exactly the capacity of bridge.
- More than 1 – If the traffic on road is higher than the capacity of bridge and cars have to wait to pass trough the bridge.
This number is not normalized according to your cpu
. In Multiprocessor system, load 2 mean 100 % utilization of we are using dual-core processor, load 4 means 100% utilization if we are using quad-core.
You can get your system load using
uptime
cat /proc/loadavg
top
$uptime 22:49:47 up 11:47, 4 users, load average: 2.20, 1.03, 0.82
Here the last three number representing the system load average for 1, 5 and 15 minutes respectively.
The example above indicates that on average there were 2.20 processes waiting to be scheduled on the run-queue measured over the last minute.