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| author | Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> | 2008-01-25 21:08:00 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-25 21:08:00 +0100 |
| commit | 58e2d4ca581167c2a079f4ee02be2f0bc52e8729 (patch) | |
| tree | 9a8c8324785800f3577fb897ca3e2ae21ad8c55a /kernel/sched_fair.c | |
| parent | ec2c507fe8c8fa3c04fc6cb99a382a965c477379 (diff) | |
| download | lwn-58e2d4ca581167c2a079f4ee02be2f0bc52e8729.tar.gz lwn-58e2d4ca581167c2a079f4ee02be2f0bc52e8729.zip | |
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.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 0c5fdce67228..30ae9c2a2861 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); } /* |