From 5c0342ca7ef17220d8dd2da68d0d349c26ab19df Mon Sep 17 00:00:00 2001 From: Claudio Scordino Date: Tue, 14 Nov 2017 12:19:26 +0100 Subject: [PATCH] sched/deadline: Fix the description of runtime accounting in the documentation Signed-off-by: Claudio Scordino Signed-off-by: Luca Abeni Acked-by: Daniel Bristot de Oliveira Acked-by: Peter Zijlstra Cc: Jonathan Corbet Cc: Linus Torvalds Cc: Mathieu Poirier Cc: Thomas Gleixner Cc: Tommaso Cucinotta Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1510658366-28995-1-git-send-email-claudio@evidence.eu.com Signed-off-by: Ingo Molnar --- Documentation/scheduler/sched-deadline.txt | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/Documentation/scheduler/sched-deadline.txt b/Documentation/scheduler/sched-deadline.txt index e89e36ec15a5..8ce78f82ae23 100644 --- a/Documentation/scheduler/sched-deadline.txt +++ b/Documentation/scheduler/sched-deadline.txt @@ -204,10 +204,17 @@ 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 (subjected to RT throttling + limits); + - Uinact is the (per runqueue) inactive utilization, computed as + (this_bq - running_bw); + - Uextra is the (per runqueue) extra reclaimable utilization + (subjected to RT throttling limits). Let's now see a trivial example of two deadline tasks with runtime equal