[tip:sched/core] sched/fair: Clean up load average references

From: tip-bot for Yuyang Du
Date: Mon Aug 03 2015 - 13:13:07 EST


Commit-ID: 7ea241afbf4924c58d41078599f7a32ba49fb985
Gitweb: http://git.kernel.org/tip/7ea241afbf4924c58d41078599f7a32ba49fb985
Author: Yuyang Du <yuyang.du@xxxxxxxxx>
AuthorDate: Wed, 15 Jul 2015 08:04:42 +0800
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 3 Aug 2015 12:24:32 +0200

sched/fair: Clean up load average references

For cfs_rq, we have load.weight, runnable_load_avg, and load_avg.
Clean up how they are used:

- First, as group sched_entity already largely uses load_avg, we now expand
to use load_avg in all cases.

- Second, for CPU-wide load balancing, we choose to use runnable_load_avg
in all cases, which is the same as before this series.

Signed-off-by: Yuyang Du <yuyang.du@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: arjan@xxxxxxxxxxxxxxx
Cc: bsegall@xxxxxxxxxx
Cc: dietmar.eggemann@xxxxxxx
Cc: fengguang.wu@xxxxxxxxx
Cc: len.brown@xxxxxxxxx
Cc: morten.rasmussen@xxxxxxx
Cc: pjt@xxxxxxxxxx
Cc: rafael.j.wysocki@xxxxxxxxx
Cc: umgwanakikbuti@xxxxxxxxx
Cc: vincent.guittot@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1436918682-4971-8-git-send-email-yuyang.du@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/fair.c | 44 +++++++++++++++++++++++++++++---------------
1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1a878d5..858b94a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -685,6 +685,9 @@ void init_entity_runnable_average(struct sched_entity *se)
sa->util_sum = LOAD_AVG_MAX;
/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
}
+
+static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq);
+static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq);
#else
void init_entity_runnable_average(struct sched_entity *se)
{
@@ -2360,7 +2363,7 @@ static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
*/
tg_weight = atomic_long_read(&tg->load_avg);
tg_weight -= cfs_rq->tg_load_avg_contrib;
- tg_weight += cfs_rq->avg.load_avg;
+ tg_weight += cfs_rq_load_avg(cfs_rq);

return tg_weight;
}
@@ -2370,7 +2373,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
long tg_weight, load, shares;

tg_weight = calc_tg_weight(tg, cfs_rq);
- load = cfs_rq->avg.load_avg;
+ load = cfs_rq_load_avg(cfs_rq);

shares = (tg->shares * load);
if (tg_weight)
@@ -2796,6 +2799,16 @@ void idle_exit_fair(struct rq *this_rq)
{
}

+static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq)
+{
+ return cfs_rq->runnable_load_avg;
+}
+
+static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)
+{
+ return cfs_rq->avg.load_avg;
+}
+
static int idle_balance(struct rq *this_rq);

#else /* CONFIG_SMP */
@@ -4270,6 +4283,12 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
sched_avg_update(this_rq);
}

+/* Used instead of source_load when we know the type == 0 */
+static unsigned long weighted_cpuload(const int cpu)
+{
+ return cfs_rq_runnable_load_avg(&cpu_rq(cpu)->cfs);
+}
+
#ifdef CONFIG_NO_HZ_COMMON
/*
* There is no sane way to deal with nohz on smp when using jiffies because the
@@ -4291,7 +4310,7 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
static void update_idle_cpu_load(struct rq *this_rq)
{
unsigned long curr_jiffies = READ_ONCE(jiffies);
- unsigned long load = this_rq->cfs.avg.load_avg;
+ unsigned long load = weighted_cpuload(cpu_of(this_rq));
unsigned long pending_updates;

/*
@@ -4337,7 +4356,7 @@ void update_cpu_load_nohz(void)
*/
void update_cpu_load_active(struct rq *this_rq)
{
- unsigned long load = this_rq->cfs.avg.load_avg;
+ unsigned long load = weighted_cpuload(cpu_of(this_rq));
/*
* See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
*/
@@ -4345,12 +4364,6 @@ void update_cpu_load_active(struct rq *this_rq)
__update_cpu_load(this_rq, load, 1);
}

-/* Used instead of source_load when we know the type == 0 */
-static unsigned long weighted_cpuload(const int cpu)
-{
- return cpu_rq(cpu)->cfs.avg.load_avg;
-}
-
/*
* Return a low guess at the load of a migration-source cpu weighted
* according to the scheduling class and "nice" value.
@@ -4398,7 +4411,7 @@ static unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running);
- unsigned long load_avg = rq->cfs.avg.load_avg;
+ unsigned long load_avg = weighted_cpuload(cpu);

if (nr_running)
return load_avg / nr_running;
@@ -4517,7 +4530,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
/*
* w = rw_i + @wl
*/
- w = se->my_q->avg.load_avg + wl;
+ w = cfs_rq_load_avg(se->my_q) + wl;

/*
* wl = S * s'_i; see (2)
@@ -5862,13 +5875,14 @@ static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq)
}

if (!se) {
- cfs_rq->h_load = cfs_rq->avg.load_avg;
+ cfs_rq->h_load = cfs_rq_load_avg(cfs_rq);
cfs_rq->last_h_load_update = now;
}

while ((se = cfs_rq->h_load_next) != NULL) {
load = cfs_rq->h_load;
- load = div64_ul(load * se->avg.load_avg, cfs_rq->avg.load_avg + 1);
+ load = div64_ul(load * se->avg.load_avg,
+ cfs_rq_load_avg(cfs_rq) + 1);
cfs_rq = group_cfs_rq(se);
cfs_rq->h_load = load;
cfs_rq->last_h_load_update = now;
@@ -5881,7 +5895,7 @@ static unsigned long task_h_load(struct task_struct *p)

update_cfs_rq_h_load(cfs_rq);
return div64_ul(p->se.avg.load_avg * cfs_rq->h_load,
- cfs_rq->avg.load_avg + 1);
+ cfs_rq_load_avg(cfs_rq) + 1);
}
#else
static inline void update_blocked_averages(int cpu)
--
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