[tip:sched/core] sched: Make set_*_buddy() work on non-task entities

From: tip-bot for Venkatesh Pallipadi
Date: Tue Apr 19 2011 - 08:05:36 EST


Commit-ID: 69c80f3e9d3c569f8a3cee94ba1a324b5a7fa6b9
Gitweb: http://git.kernel.org/tip/69c80f3e9d3c569f8a3cee94ba1a324b5a7fa6b9
Author: Venkatesh Pallipadi <venki@xxxxxxxxxx>
AuthorDate: Wed, 13 Apr 2011 18:21:09 -0700
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 19 Apr 2011 10:08:37 +0200

sched: Make set_*_buddy() work on non-task entities

Make set_*_buddy() work on non-task sched_entity, to facilitate the
use of next_buddy to cache a group entity in cases where one of the
tasks within that entity sleeps or gets preempted.

set_skip_buddy() was incorrectly comparing the policy of task that is
yielding to be not equal to SCHED_IDLE. Yielding should happen even
when task yielding is SCHED_IDLE. This change removes the policy check
on the yielding task.

Signed-off-by: Venkatesh Pallipadi <venki@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1302744070-30079-2-git-send-email-venki@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/sched_fair.c | 24 ++++++++++++------------
1 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 8744593..501ab63 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1846,26 +1846,26 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)

static void set_last_buddy(struct sched_entity *se)
{
- if (likely(task_of(se)->policy != SCHED_IDLE)) {
- for_each_sched_entity(se)
- cfs_rq_of(se)->last = se;
- }
+ if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
+ return;
+
+ for_each_sched_entity(se)
+ cfs_rq_of(se)->last = se;
}

static void set_next_buddy(struct sched_entity *se)
{
- if (likely(task_of(se)->policy != SCHED_IDLE)) {
- for_each_sched_entity(se)
- cfs_rq_of(se)->next = se;
- }
+ if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
+ return;
+
+ for_each_sched_entity(se)
+ cfs_rq_of(se)->next = se;
}

static void set_skip_buddy(struct sched_entity *se)
{
- if (likely(task_of(se)->policy != SCHED_IDLE)) {
- for_each_sched_entity(se)
- cfs_rq_of(se)->skip = se;
- }
+ for_each_sched_entity(se)
+ cfs_rq_of(se)->skip = se;
}

/*
--
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