[tip:sched/core] sched/fair: Make update_min_vruntime() more readable

From: tip-bot for Byungchul Park
Date: Mon Sep 05 2016 - 07:54:16 EST


Commit-ID: 97a7142f157a6361a659ff3eec2c3cf636bd7490
Gitweb: http://git.kernel.org/tip/97a7142f157a6361a659ff3eec2c3cf636bd7490
Author: Byungchul Park <byungchul.park@xxxxxxx>
AuthorDate: Sun, 5 Jul 2015 18:33:48 +0900
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 5 Sep 2016 13:29:41 +0200

sched/fair: Make update_min_vruntime() more readable

The update_min_vruntime() control flow can be simplified.

Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: minchan.kim@xxxxxxx
Link: http://lkml.kernel.org/r/1436088829-25768-1-git-send-email-byungchul.park@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/fair.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 61d4854..9a18aae 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -464,20 +464,17 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
{
u64 vruntime = cfs_rq->min_vruntime;

- if (cfs_rq->curr)
- vruntime = cfs_rq->curr->vruntime;
-
if (cfs_rq->rb_leftmost) {
struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost,
struct sched_entity,
run_node);

- if (!cfs_rq->curr)
- vruntime = se->vruntime;
- else
- vruntime = min_vruntime(vruntime, se->vruntime);
+ vruntime = se->vruntime;
}

+ if (cfs_rq->curr)
+ vruntime = min_vruntime(vruntime, cfs_rq->curr->vruntime);
+
/* ensure we never gain time by being placed backwards. */
cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);
#ifndef CONFIG_64BIT
@@ -5988,7 +5985,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
*
* The adjacency matrix of the resulting graph is given by:
*
- * log_2 n
+ * log_2 n
* A_i,j = \Union (i % 2^k == 0) && i / 2^(k+1) == j / 2^(k+1) (6)
* k = 0
*
@@ -6034,7 +6031,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
*
* [XXX write more on how we solve this.. _after_ merging pjt's patches that
* rewrite all of this once again.]
- */
+ */

static unsigned long __read_mostly max_load_balance_interval = HZ/10;

@@ -6696,7 +6693,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
/*
* !SD_OVERLAP domains can assume that child groups
* span the current group.
- */
+ */

group = child->groups;
do {