[PATCH 1/2] sched: Make set_*_buddy work on non-task entity -v2

From: Venkatesh Pallipadi
Date: Wed Apr 13 2011 - 21:21:46 EST


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 wrongly 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>
---
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 80ecd09..d3513b7 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1826,26 +1826,26 @@ 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;
}

/*
--
1.7.3.1

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