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 <huawei.libin@huawei.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1378706740-7500-1-git-send-email-huawei.libin@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Li Bin 2013-09-09 14:05:40 +08:00 committed by Ingo Molnar
parent fc840914e9
commit 3b524d6094

View File

@ -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