Messages in this thread Patch in this message | | | Date | Tue, 25 Aug 2009 15:19:14 +0530 | From | Bharata B Rao <> | Subject | [RFC v1 PATCH 2/7] sched: Maintain aggregated tasks count in cfs_rq at each hierarchy level |
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sched: Maintain aggregated tasks count in cfs_rq at each hierarchy level
From: Bharata B Rao <bharata@linux.vnet.ibm.com>
This patch adds a counter to cfs_rq (->nr_tasks_running) to record the aggregated tasks count at each level in the task group hierarchy. This is needed by later hard limit patches where it is required to know how many tasks go off the rq when a throttled group entity is dequeued.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> --- kernel/sched.c | 4 ++++ kernel/sched_debug.c | 2 ++ kernel/sched_fair.c | 23 +++++++++++++++++++++++ 3 files changed, 29 insertions(+)
--- a/kernel/sched.c +++ b/kernel/sched.c @@ -477,6 +477,10 @@ struct cfs_rq { unsigned long rq_weight; #endif #endif + /* + * Number of tasks at this heirarchy. + */ + unsigned long nr_tasks_running; }; /* Real-Time classes' related field in a runqueue: */ --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -214,6 +214,8 @@ void print_cfs_rq(struct seq_file *m, in #ifdef CONFIG_SMP SEQ_printf(m, " .%-30s: %lu\n", "shares", cfs_rq->shares); #endif + SEQ_printf(m, " .%-30s: %ld\n", "nr_tasks_running", + cfs_rq->nr_tasks_running); print_cfs_group_stats(m, cpu, cfs_rq->tg); #endif } --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -243,6 +243,27 @@ find_matching_se(struct sched_entity **s #endif /* CONFIG_FAIR_GROUP_SCHED */ +static void add_cfs_rq_tasks_running(struct sched_entity *se, + unsigned long count) +{ + struct cfs_rq *cfs_rq; + + for_each_sched_entity(se) { + cfs_rq = cfs_rq_of(se); + cfs_rq->nr_tasks_running += count; + } +} + +static void sub_cfs_rq_tasks_running(struct sched_entity *se, + unsigned long count) +{ + struct cfs_rq *cfs_rq; + + for_each_sched_entity(se) { + cfs_rq = cfs_rq_of(se); + cfs_rq->nr_tasks_running -= count; + } +} /************************************************************** * Scheduling class tree data structure manipulation methods: @@ -969,6 +990,7 @@ static void enqueue_task_fair(struct rq wakeup = 1; } + add_cfs_rq_tasks_running(&p->se, 1); hrtick_update(rq); } @@ -991,6 +1013,7 @@ static void dequeue_task_fair(struct rq sleep = 1; } + sub_cfs_rq_tasks_running(&p->se, 1); hrtick_update(rq); }
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