sched, docs: Update schedstats documentation to version 15

Version 15 of schedstats was introduced in:

   67aa0f767a: sched: remove unused fields from struct rq

and removed three unused counters in sched_yield(). Update
the documentation.

Signed-off-by: Javi Merino <cibervicho@gmail.com>
Cc: henrix@sapo.pt
Cc: rdunlap@xenotime.net
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1296515496-8229-1-git-send-email-cibervicho@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Javi Merino 2011-01-31 23:11:36 +00:00 committed by Ingo Molnar
parent ebf53826e1
commit 1e1dbb259c

View File

@ -1,3 +1,7 @@
Version 15 of schedstats dropped counters for some sched_yield:
yld_exp_empty, yld_act_empty and yld_both_empty. Otherwise, it is
identical to version 14.
Version 14 of schedstats includes support for sched_domains, which hit the
mainline kernel in 2.6.20 although it is identical to the stats from version
12 which was in the kernel from 2.6.13-2.6.19 (version 13 never saw a kernel
@ -28,32 +32,25 @@ to write their own scripts, the fields are described here.
CPU statistics
--------------
cpu<N> 1 2 3 4 5 6 7 8 9 10 11 12
cpu<N> 1 2 3 4 5 6 7 8 9
NOTE: In the sched_yield() statistics, the active queue is considered empty
if it has only one process in it, since obviously the process calling
sched_yield() is that process.
First four fields are sched_yield() statistics:
1) # of times both the active and the expired queue were empty
2) # of times just the active queue was empty
3) # of times just the expired queue was empty
4) # of times sched_yield() was called
First field is a sched_yield() statistic:
1) # of times sched_yield() was called
Next three are schedule() statistics:
5) # of times we switched to the expired queue and reused it
6) # of times schedule() was called
7) # of times schedule() left the processor idle
2) # of times we switched to the expired queue and reused it
3) # of times schedule() was called
4) # of times schedule() left the processor idle
Next two are try_to_wake_up() statistics:
8) # of times try_to_wake_up() was called
9) # of times try_to_wake_up() was called to wake up the local cpu
5) # of times try_to_wake_up() was called
6) # of times try_to_wake_up() was called to wake up the local cpu
Next three are statistics describing scheduling latency:
10) sum of all time spent running by tasks on this processor (in jiffies)
11) sum of all time spent waiting to run by tasks on this processor (in
7) sum of all time spent running by tasks on this processor (in jiffies)
8) sum of all time spent waiting to run by tasks on this processor (in
jiffies)
12) # of timeslices run on this cpu
9) # of timeslices run on this cpu
Domain statistics