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authorSrivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>2008-01-25 21:08:00 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-25 21:08:00 +0100
commit58e2d4ca581167c2a079f4ee02be2f0bc52e8729 (patch)
tree9a8c8324785800f3577fb897ca3e2ae21ad8c55a /kernel/sched_fair.c
parentec2c507fe8c8fa3c04fc6cb99a382a965c477379 (diff)
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sched: group scheduling, change how cpu load is calculated
This patch changes how the cpu load exerted by fair_sched_class tasks is calculated. Load exerted by fair_sched_class tasks on a cpu is now a summation of the group weights, rather than summation of task weights. Weight exerted by a group on a cpu is dependent on the shares allocated to it. This version of patch has a minor impact on code size, but should have no runtime/functional impact for !CONFIG_FAIR_GROUP_SCHED. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 0c5fdce..30ae9c2 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -760,15 +760,26 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se)
static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup)
{
struct cfs_rq *cfs_rq;
- struct sched_entity *se = &p->se;
+ struct sched_entity *se = &p->se,
+ *topse = NULL; /* Highest schedulable entity */
+ int incload = 1;
for_each_sched_entity(se) {
- if (se->on_rq)
+ topse = se;
+ if (se->on_rq) {
+ incload = 0;
break;
+ }
cfs_rq = cfs_rq_of(se);
enqueue_entity(cfs_rq, se, wakeup);
wakeup = 1;
}
+ /* Increment cpu load if we just enqueued the first task of a group on
+ * 'rq->cpu'. 'topse' represents the group to which task 'p' belongs
+ * at the highest grouping level.
+ */
+ if (incload)
+ inc_cpu_load(rq, topse->load.weight);
}
/*
@@ -779,16 +790,28 @@ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup)
static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
{
struct cfs_rq *cfs_rq;
- struct sched_entity *se = &p->se;
+ struct sched_entity *se = &p->se,
+ *topse = NULL; /* Highest schedulable entity */
+ int decload = 1;
for_each_sched_entity(se) {
+ topse = se;
cfs_rq = cfs_rq_of(se);
dequeue_entity(cfs_rq, se, sleep);
/* Don't dequeue parent if it has other entities besides us */
- if (cfs_rq->load.weight)
+ if (cfs_rq->load.weight) {
+ if (parent_entity(se))
+ decload = 0;
break;
+ }
sleep = 1;
}
+ /* Decrement cpu load if we just dequeued the last task of a group on
+ * 'rq->cpu'. 'topse' represents the group to which task 'p' belongs
+ * at the highest grouping level.
+ */
+ if (decload)
+ dec_cpu_load(rq, topse->load.weight);
}
/*