System information

176 System Analysis and Tuning Guide
runnable tasks:
task PID tree-key switches prio exec-runtime sum-exec sum-
sleep
--------------------------------------------------------------------------
R cat 16884 54410632.307072 0 120 54410632.307072 13.836804
0.000000
/proc/schedstat
Displays statistics relevant to the current run queue. Also domain-specific statis-
tics for SMP systems are displayed for all connected processors. Because the out-
put format is not user-friendly, read the contents of /usr/src/linux/Doc
umentation/scheduler/sched-stats.txt for more information.
/proc/PID/sched
Displays scheduling information on the process with id PID.
saturn.example.com:~ # cat /proc/`pidof nautilus`/sched
nautilus (4009, #threads: 1)
---------------------------------------------------------
se.exec_start : 2419575150.560531
se.vruntime : 54549795.870151
se.sum_exec_runtime : 4867855.829415
se.avg_overlap : 0.401317
se.avg_wakeup : 3.247651
se.avg_running : 0.323432
se.wait_start : 0.000000
se.sleep_start : 2419575150.560531
[...]
nr_voluntary_switches : 938552
nr_involuntary_switches : 71872
se.load.weight : 1024
policy : 0
prio : 120
clock-delta : 109
14.5 For More Information
To get a compact knowledge about Linux kernel task scheduling, you need to explore
several information sources. Here are some of them:
• For task scheduler System Calls description, see the relevant manual page (for ex-
ample man 2 sched_setaffinity).
• General information on scheduling is described in Scheduling [http://
en.wikipedia.org/wiki/Scheduling_(computing)] wiki page.