luck/tmp_suning_uos_patched
1
0
Fork 1
Code Issues Pull Requests Packages Projects Releases Wiki Activity

sched/dl/Documentation: Clarify the relationship between tasks' deadlines and absolute scheduling deadlines

Browse Source 
Clarify what is the relationship between tasks' parameters and scheduling
parameters, explaining how to set the scheduling parameters so that all the
absolute deadlines of a task are respected.

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: henrik@austad.us
Cc: juri.lelli@gmail.com
Cc: raistlin@linux.it
Link: http://lkml.kernel.org/r/1431954032-16473-9-git-send-email-luca.abeni@unitn.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Luca Abeni 2015-05-18 15:00:31 +02:00 committed by Ingo Molnar
parent 134136c4b7
commit 7874085890
1 changed files with 11 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Documentation/scheduler/sched-deadline.txt
View File

@ -249,9 +249,17 @@ CONTENTS
the total utilization is smaller or equal than M then the response times of
the tasks are limited.
SCHED_DEADLINE can be used to schedule real-time tasks guaranteeing that
the jobs' deadlines of a task are respected. In order to do this, a task
must be scheduled by setting:
Finally, it is important to understand the relationship between the
SCHED_DEADLINE scheduling parameters described in Section 2 (runtime,
deadline and period) and the real-time task parameters (WCET, D, P)
described in this section. Note that the tasks' temporal constraints are
represented by its absolute deadlines d_j = r_j + D described above, while
SCHED_DEADLINE schedules the tasks according to scheduling deadlines (see
Section 2).
If an admission test is used to guarantee that the scheduling deadlines
are respected, then SCHED_DEADLINE can be used to schedule real-time tasks
guaranteeing that all the jobs' deadlines of a task are respected.
In order to do this, a task must be scheduled by setting:
- runtime >= WCET
- deadline = D