性能測定

$ /usr/bin/time -v wc /etc/hosts
 10  29 273 /etc/hosts
        Command being timed: "wc /etc/hosts"
        User time (seconds): 0.00
        System time (seconds): 0.00
        Percent of CPU this job got: 100%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 1952
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 167
        Voluntary context switches: 1
        Involuntary context switches: 10
        Swaps: 0
        File system inputs: 0
        File system outputs: 0
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0

Maximum resident set size:メモリ使用量
Major (requiring I/O) page faults:I/Oにともなうページフォルト
Minor (reclaiming a frame) page faults:それ以外のページフォルト
Voluntary context switches:自発的コンテキストスイッチ
Involuntary context switches:時間を使いきった等によるスケジュールなどからのコンテキストスイッチ
参考
USP MAGAZINE vol4. P15 FreeBSDのtimeコマンド