From: Luca Abeni <luca.abeni@unitn.it>
To: peterz@infradead.org
Cc: henrik@austad.us, juri.lelli@gmail.com, raistlin@linux.it,
mingo@kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, Luca Abeni <luca.abeni@unitn.it>
Subject: [PATCH 8/9] Documentation/scheduler/sched-deadline.txt: relationship between tasks' deadlines and scheduling deadlines
Date: Mon, 18 May 2015 15:00:31 +0200 [thread overview]
Message-ID: <1431954032-16473-9-git-send-email-luca.abeni@unitn.it> (raw)
In-Reply-To: <1431954032-16473-1-git-send-email-luca.abeni@unitn.it>
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>
---
Documentation/scheduler/sched-deadline.txt | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/Documentation/scheduler/sched-deadline.txt b/Documentation/scheduler/sched-deadline.txt
index bd9ce00..ead13bcc 100644
--- a/Documentation/scheduler/sched-deadline.txt
+++ b/Documentation/scheduler/sched-deadline.txt
@@ -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
--
1.7.9.5
next prev parent reply other threads:[~2015-05-18 13:05 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-18 13:00 [PATCH 0/9] SCHED_DEADLINE documentation update Luca Abeni
2015-05-18 13:00 ` [PATCH 1/9] Documentation/scheduler/sched-deadline.txt: correct definition of density as C_i/min{D_i,P_i} Luca Abeni
2015-05-19 7:23 ` [tip:sched/core] sched/dl/Documentation: Correct the " tip-bot for Zhiqiang Zhang
2015-05-18 13:00 ` [PATCH 2/9] Documentation/scheduler/sched-deadline.txt: switch to American English Luca Abeni
2015-05-19 7:23 ` [tip:sched/core] sched/dl/Documentation: Switch " tip-bot for Luca Abeni
2015-05-18 13:00 ` [PATCH 3/9] Documentation/scheduler/sched-deadline.txt: fix typos Luca Abeni
2015-05-19 7:24 ` [tip:sched/core] sched/dl/Documentation: Fix typos tip-bot for Luca Abeni
2015-05-18 13:00 ` [PATCH 4/9] Documentation/scheduler/sched-deadline.txt: use consistent namings Luca Abeni
2015-05-19 7:24 ` [tip:sched/core] sched/dl/Documentation: Use consistent naming tip-bot for Luca Abeni
2015-05-18 13:00 ` [PATCH 5/9] Documentation/scheduler/sched-deadline.txt: remove _i from sum, max and min Luca Abeni
2015-05-19 7:24 ` [tip:sched/core] sched/dl/Documentation: Clarify indexing notation tip-bot for Luca Abeni
2015-05-18 13:00 ` [PATCH 6/9] Documentation/scheduler/sched-deadline.txt: Some notes on EDF schedulability Luca Abeni
2015-05-19 7:25 ` [tip:sched/core] sched/dl/Documentation: Add some " tip-bot for Luca Abeni
2015-05-18 13:00 ` [PATCH 7/9] Documentation/scheduler/sched-deadline.txt: add some references Luca Abeni
2015-05-19 7:25 ` [tip:sched/core] sched/dl/Documentation: Add " tip-bot for Luca Abeni
2015-05-18 13:00 ` Luca Abeni [this message]
2015-05-19 7:25 ` [tip:sched/core] sched/dl/Documentation: Clarify the relationship between tasks' deadlines and absolute scheduling deadlines tip-bot for Luca Abeni
2015-05-18 13:00 ` [PATCH 9/9] Documentation/scheduler/sched-deadline.txt: Split Section 3 Luca Abeni
2015-05-19 7:26 ` [tip:sched/core] sched/dl/Documentation: " tip-bot for Luca Abeni
2015-05-19 13:26 ` [PATCH 0/9] SCHED_DEADLINE documentation update Henrik Austad
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