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Message-ID: <20100213025513.23325.10971.stgit@kitami.corp.google.com>
Date: Fri, 12 Feb 2010 18:55:13 -0800
From: Paul <pjt@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: Paul Menage <menage@...gle.com>,
Srivatsa Vaddagiri <vatsa@...ibm.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Gautham R Shenoy <ego@...ibm.com>,
Dhaval Giani <dhaval.giani@...il.com>,
Balbir Singh <balbir@...ux.vnet.ibm.com>,
Herbert Poetzl <herbert@...hfloor.at>,
Chris Friesen <cfriesen@...tel.com>,
Avi Kivity <avi@...hat.com>,
Bharata B Rao <bharata@...ux.vnet.ibm.com>,
Nikhil Rao <ncrao@...gle.com>, Ingo Molnar <mingo@...e.hu>,
Kamalesh Babulal <kamalesh@...ux.vnet.ibm.com>,
Mike Waychison <mikew@...gle.com>,
Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
Pavel Emelyanov <xemul@...nvz.org>
Subject: [RFC PATCH v1 4/4] sched: unthrottle cfs_rq(s) who ran out of quota
at period refresh
From: Paul Turner <pjt@...gle.com>
At the start of a new period there are several actions we must take:
- Refresh global bandwidth pool
- Unthrottle entities who ran out of quota as refreshed bandwidth permits
Unthrottled entities have the cfs_rq->throttled flag set and are re-enqueued
into the cfs entity hierarchy.
sched_rt_period_mask() is refactored slightly into sched_bw_period_mask()
since it is now shared by both cfs and rt bandwidth period timers.
The !CONFIG_RT_GROUP_SCHED && CONFIG_SMP case has been collapsed to use
rd->span instead of cpu_online_mask since I think that was incorrect before
(don't want to hit cpu's outside of your root_domain for RT bandwidth).
Signed-off-by: Paul Turner <pjt@...gle.com>
Signed-off-by: Nikhil Rao <ncrao@...gle.com>
---
kernel/sched.c | 17 +++++++++++
kernel/sched_fair.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++-----
kernel/sched_rt.c | 19 +-----------
3 files changed, 90 insertions(+), 26 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 88fd401..a79bb23 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1573,6 +1573,8 @@ static int tg_nop(struct task_group *tg, void *data)
}
#endif
+static inline const struct cpumask *sched_bw_period_mask(void);
+
#ifdef CONFIG_SMP
/* Used instead of source_load when we know the type == 0 */
static unsigned long weighted_cpuload(const int cpu)
@@ -1927,6 +1929,18 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
#endif
}
+#ifdef CONFIG_SMP
+static inline const struct cpumask *sched_bw_period_mask(void)
+{
+ return cpu_rq(smp_processor_id())->rd->span;
+}
+#else
+static inline const struct cpumask *sched_bw_period_mask(void)
+{
+ return cpu_online_mask;
+}
+#endif
+
#ifdef CONFIG_CFS_BANDWIDTH
/*
* default period for cfs group bandwidth.
@@ -10769,6 +10783,9 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
cfs_rq->quota_assigned = RUNTIME_INF;
else
cfs_rq->quota_assigned = 0;
+
+ if (cfs_rq_throttled(cfs_rq))
+ unthrottle_cfs_rq(cfs_rq);
raw_spin_unlock_irq(&rq->lock);
}
mutex_unlock(&mutex);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index da85200..814511a 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -267,6 +267,13 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse)
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_CFS_BANDWIDTH
+static inline
+struct cfs_rq *cfs_bandwidth_cfs_rq(struct cfs_bandwidth *cfs_b, int cpu)
+{
+ return container_of(cfs_b, struct task_group,
+ cfs_bandwidth)->cfs_rq[cpu];
+}
+
static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
{
return &tg->cfs_bandwidth;
@@ -793,8 +800,9 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
se->vruntime = vruntime;
}
-#define ENQUEUE_WAKEUP 1
-#define ENQUEUE_MIGRATE 2
+#define ENQUEUE_WAKEUP 1
+#define ENQUEUE_MIGRATE 2
+#define ENQUEUE_UNTHROTTLE 4
static void
enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
@@ -803,7 +811,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* Update the normalized vruntime before updating min_vruntime
* through callig update_curr().
*/
- if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATE))
+ if (!(flags & (ENQUEUE_WAKEUP | ENQUEUE_UNTHROTTLE)) ||
+ (flags & ENQUEUE_MIGRATE))
se->vruntime += cfs_rq->min_vruntime;
/*
@@ -812,16 +821,15 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
update_curr(cfs_rq);
if (!entity_is_task(se) && (cfs_rq_throttled(group_cfs_rq(se)) ||
- !group_cfs_rq(se)->nr_running)) {
+ !group_cfs_rq(se)->nr_running))
return;
- }
account_entity_enqueue(cfs_rq, se);
- if (flags & ENQUEUE_WAKEUP) {
+ if (flags & (ENQUEUE_WAKEUP | ENQUEUE_UNTHROTTLE))
place_entity(cfs_rq, se, 0);
+ if (flags & ENQUEUE_WAKEUP)
enqueue_sleeper(cfs_rq, se);
- }
update_stats_enqueue(cfs_rq, se);
check_spread(cfs_rq, se);
@@ -1232,6 +1240,26 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
cfs_rq->throttled = 1;
}
+static void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
+{
+ struct sched_entity *se;
+ int flags = ENQUEUE_UNTHROTTLE;
+
+ se = cfs_rq->tg->se[cfs_rq->rq->cpu];
+
+ cfs_rq->throttled = 0;
+ for_each_sched_entity(se) {
+ if (se->on_rq)
+ break;
+
+ cfs_rq = cfs_rq_of(se);
+ enqueue_entity(cfs_rq, se, flags);
+ if (cfs_rq_throttled(cfs_rq))
+ break;
+ flags = ENQUEUE_WAKEUP;
+ }
+}
+
static void account_cfs_rq_quota(struct cfs_rq *cfs_rq,
unsigned long delta_exec)
{
@@ -1254,8 +1282,44 @@ static void account_cfs_rq_quota(struct cfs_rq *cfs_rq,
static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
{
- return 1;
+ int i, idle = 1;
+ u64 delta;
+ const struct cpumask *span;
+
+ if (cfs_b->quota == RUNTIME_INF)
+ return 1;
+
+ /* reset group quota */
+ raw_spin_lock(&cfs_b->lock);
+ cfs_b->runtime = cfs_b->quota;
+ raw_spin_unlock(&cfs_b->lock);
+
+ span = sched_bw_period_mask();
+ for_each_cpu(i, span) {
+ struct rq *rq = cpu_rq(i);
+ struct cfs_rq *cfs_rq = cfs_bandwidth_cfs_rq(cfs_b, i);
+
+ if (!cfs_rq->nr_running)
+ idle = 0;
+
+ if (!cfs_rq_throttled(cfs_rq))
+ continue;
+
+ delta = tg_request_cfs_quota(cfs_rq->tg);
+
+ if (delta) {
+ raw_spin_lock(&rq->lock);
+ cfs_rq->quota_assigned += delta;
+
+ if (cfs_rq->quota_used < cfs_rq->quota_assigned)
+ unthrottle_cfs_rq(cfs_rq);
+ raw_spin_unlock(&rq->lock);
+ }
+ }
+
+ return idle;
}
+
#endif
#ifdef CONFIG_SMP
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index f48328a..cab78f6 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -235,18 +235,6 @@ static int rt_se_boosted(struct sched_rt_entity *rt_se)
return p->prio != p->normal_prio;
}
-#ifdef CONFIG_SMP
-static inline const struct cpumask *sched_rt_period_mask(void)
-{
- return cpu_rq(smp_processor_id())->rd->span;
-}
-#else
-static inline const struct cpumask *sched_rt_period_mask(void)
-{
- return cpu_online_mask;
-}
-#endif
-
static inline
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
{
@@ -296,11 +284,6 @@ static inline int rt_rq_throttled(struct rt_rq *rt_rq)
return rt_rq->rt_throttled;
}
-static inline const struct cpumask *sched_rt_period_mask(void)
-{
- return cpu_online_mask;
-}
-
static inline
struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
{
@@ -518,7 +501,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
return 1;
- span = sched_rt_period_mask();
+ span = sched_bw_period_mask();
for_each_cpu(i, span) {
int enqueue = 0;
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
--
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