2017-10-13 10:11:55

by Claudio Scordino

[permalink] [raw]
Subject: [PATCH] sched/deadline: fix runtime accounting in documentation

Signed-off-by: Claudio Scordino <[email protected]>
Signed-off-by: Luca Abeni <[email protected]>
---
Documentation/scheduler/sched-deadline.txt | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/Documentation/scheduler/sched-deadline.txt b/Documentation/scheduler/sched-deadline.txt
index e89e36e..79f40c6 100644
--- a/Documentation/scheduler/sched-deadline.txt
+++ b/Documentation/scheduler/sched-deadline.txt
@@ -204,10 +204,16 @@ CONTENTS
It does so by decrementing the runtime of the executing task Ti at a pace equal
to

- dq = -max{ Ui, (1 - Uinact) } dt
+ dq = -max{ Ui / Umax, (1 - Uinact - Uextra) } dt

- where Uinact is the inactive utilization, computed as (this_bq - running_bw),
- and Ui is the bandwidth of task Ti.
+ where:
+
+ - Ui is the bandwidth of task Ti;
+ - Umax is the maximum reclaimable utilization (subject to RT limits);
+ - Uinact is the (per runqueue) inactive utilization, computed as
+ (this_bq - running_bw);
+ - Uextra is the (per runqueue) extra reclaimable utilization
+ (subject to RT limits).


Let's now see a trivial example of two deadline tasks with runtime equal
--
2.7.4


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