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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-11-16 00:47:02 +0100
committerIngo Molnar <mingo@elte.hu>2010-11-18 13:27:47 +0100
commit9e3081ca61147b29f52fddb4f7c6b6b82ea5eb7a (patch)
tree74ec7a4f3e544ed64afb6cb7abe6322ca700d19a /kernel/sched_fair.c
parentsched: Implement on-demand (active) cfs_rq list (diff)
downloadlinux-9e3081ca61147b29f52fddb4f7c6b6b82ea5eb7a.tar.xz
linux-9e3081ca61147b29f52fddb4f7c6b6b82ea5eb7a.zip
sched: Make tg_shares_up() walk on-demand
Make tg_shares_up() use the active cgroup list, this means we cannot do a strict bottom-up walk of the hierarchy, but assuming its a very wide tree with a small number of active groups it should be a win. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.754159484@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 0560e72bd732..46ff6587dc16 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2004,6 +2004,60 @@ out:
}
#ifdef CONFIG_FAIR_GROUP_SCHED
+/*
+ * update tg->load_weight by folding this cpu's load_avg
+ */
+static int tg_shares_up(struct task_group *tg, int cpu)
+{
+ struct cfs_rq *cfs_rq;
+ unsigned long flags;
+ struct rq *rq;
+ long load_avg;
+
+ if (!tg->se[cpu])
+ return 0;
+
+ rq = cpu_rq(cpu);
+ cfs_rq = tg->cfs_rq[cpu];
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+
+ update_rq_clock(rq);
+ update_cfs_load(cfs_rq, 1);
+
+ load_avg = div64_u64(cfs_rq->load_avg, cfs_rq->load_period+1);
+ load_avg -= cfs_rq->load_contribution;
+ atomic_add(load_avg, &tg->load_weight);
+ cfs_rq->load_contribution += load_avg;
+
+ /*
+ * We need to update shares after updating tg->load_weight in
+ * order to adjust the weight of groups with long running tasks.
+ */
+ update_cfs_shares(cfs_rq);
+
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+ return 0;
+}
+
+static void update_shares(int cpu)
+{
+ struct cfs_rq *cfs_rq;
+ struct rq *rq = cpu_rq(cpu);
+
+ rcu_read_lock();
+ for_each_leaf_cfs_rq(rq, cfs_rq) {
+ struct task_group *tg = cfs_rq->tg;
+
+ do {
+ tg_shares_up(tg, cpu);
+ tg = tg->parent;
+ } while (tg);
+ }
+ rcu_read_unlock();
+}
+
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
@@ -2051,6 +2105,10 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
return max_load_move - rem_load_move;
}
#else
+static inline void update_shares(int cpu)
+{
+}
+
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,