2013-09-09 06:08:18

by Li Bin

[permalink] [raw]
Subject: [PATCH] Documentation/sched: update sched-design-CFS.txt documentation

From: Li Bin <[email protected]>

2bd2d6f2dc ("sched: Replace use of entity_key()") had remove the
entity_key() which function is to subtract a tasks vruntime by
its groups minvruntime as the rbtree key.
The phrase "there is a subtraction using rq->cfs.min_vruntime
to account for possible wraparounds" in documentation feels strange
and meaningless. So remove it.

Signed-off-by: Li Bin <[email protected]>
---
Documentation/scheduler/sched-design-CFS.txt | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Documentation/scheduler/sched-design-CFS.txt b/Documentation/scheduler/sched-design-CFS.txt
index d529e02d..f14f493 100644
--- a/Documentation/scheduler/sched-design-CFS.txt
+++ b/Documentation/scheduler/sched-design-CFS.txt
@@ -66,9 +66,7 @@ rq->cfs.load value, which is the sum of the weights of the tasks queued on the
runqueue.

CFS maintains a time-ordered rbtree, where all runnable tasks are sorted by the
-p->se.vruntime key (there is a subtraction using rq->cfs.min_vruntime to
-account for possible wraparounds). CFS picks the "leftmost" task from this
-tree and sticks to it.
+p->se.vruntime key. CFS picks the "leftmost" task from this tree and sticks to it.
As the system progresses forwards, the executed tasks are put into the tree
more and more to the right --- slowly but surely giving a chance for every task
to become the "leftmost task" and thus get on the CPU within a deterministic
--
1.8.2.1


Subject: [tip:sched/core] sched/Documentation: Update sched-design-CFS.txt documentation

Commit-ID: 3b524d60943a2f9ee1194323ff9d5ee01a4d1ce1
Gitweb: http://git.kernel.org/tip/3b524d60943a2f9ee1194323ff9d5ee01a4d1ce1
Author: Li Bin <[email protected]>
AuthorDate: Mon, 9 Sep 2013 14:05:40 +0800
Committer: Ingo Molnar <[email protected]>
CommitDate: Thu, 12 Sep 2013 19:14:17 +0200

sched/Documentation: Update sched-design-CFS.txt documentation

2bd2d6f2dc ("sched: Replace use of entity_key()") had remove the
entity_key() which function is to subtract a tasks vruntime by
its groups minvruntime as the rbtree key.
The phrase "there is a subtraction using rq->cfs.min_vruntime
to account for possible wraparounds" in documentation feels strange
and meaningless. So remove it.

Signed-off-by: Li Bin <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
Documentation/scheduler/sched-design-CFS.txt | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Documentation/scheduler/sched-design-CFS.txt b/Documentation/scheduler/sched-design-CFS.txt
index d529e02d..f14f493 100644
--- a/Documentation/scheduler/sched-design-CFS.txt
+++ b/Documentation/scheduler/sched-design-CFS.txt
@@ -66,9 +66,7 @@ rq->cfs.load value, which is the sum of the weights of the tasks queued on the
runqueue.

CFS maintains a time-ordered rbtree, where all runnable tasks are sorted by the
-p->se.vruntime key (there is a subtraction using rq->cfs.min_vruntime to
-account for possible wraparounds). CFS picks the "leftmost" task from this
-tree and sticks to it.
+p->se.vruntime key. CFS picks the "leftmost" task from this tree and sticks to it.
As the system progresses forwards, the executed tasks are put into the tree
more and more to the right --- slowly but surely giving a chance for every task
to become the "leftmost task" and thus get on the CPU within a deterministic