System.Posix.LoadAvg

There are two basic ways you can get load average on a modern Linux system. First is getloadavg (3) system call. The second is /proc/loadavg file. This module provides means of getting the information from both sources. /proc/loadavg provides some additional information but we ignore that.

Documentation

data LoadAvg

Constructors

LoadAvg

Fields

sample_1 :: !Double

sample for last 1 minute

sample_5 :: !Double

sample for last 5 minutes

sample_15 :: !Double

sample for last 15 minutes

Instances

Eq LoadAvg

Ord LoadAvg

Read LoadAvg

Show LoadAvg

parseLoadAvg :: String -> LoadAvg

Tries to parse the output of /proc/loadavg. If anything goes wrong an arbitrary exception will be raised.

getLoadAvg :: IO LoadAvg

Discards error checking from getLoadAvgSafe. Will raise IO exception on error.

getLoadAvgSafe :: IO (Maybe LoadAvg)

Calls getloadavg (3) to get system load average. Provides error checking, and the result may be Nothing in case of error. If there is not enough data the samples will be copied from more recent samples.

getLoadAvgProc :: IO LoadAvg

Tries to read /proc/loadavg and parse it's output with parseLoadAvg. Either may fail with IO exception.