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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-26 13:43:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-26 13:43:25 -0800
commit6830c8db58c2616d8ba2bf45e7d98dca5f69b07f (patch)
tree7f450db9d0cf6dafa45374bb9edfb9b53d222d05 /Documentation
parent580e3d552ddf06537c7f36d1bfab04761489db9c (diff)
parent3f5fe9fef5b2da06b6319fab8123056da5217c3f (diff)
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar: "Misc fixes: a documentation fix, a Sparse warning fix and a debugging fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/debug: Fix task state recording/printout sched/deadline: Don't use dubious signed bitfields sched/deadline: Fix the description of runtime accounting in the documentation
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/scheduler/sched-deadline.txt13
1 files 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