From: Paul Turner <pjt@google.com>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Bharata B Rao <bharata@linux.vnet.ibm.com>,
Dhaval Giani <dhaval.giani@gmail.com>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Srivatsa Vaddagiri <vatsa@in.ibm.com>,
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>,
Ingo Molnar <mingo@elte.hu>, Pavel Emelyanov <xemul@openvz.org>,
Hu Tao <hutao@cn.fujitsu.com>
Subject: [patch 08/17] sched: add support for throttling group entities
Date: Wed, 06 Jul 2011 22:30:44 -0700 [thread overview]
Message-ID: <20110707053100.451271405@google.com> (raw)
In-Reply-To: 20110707053036.173186930@google.com
[-- Attachment #1: sched-bwc-throttle_entities.patch --]
[-- Type: text/plain, Size: 5863 bytes --]
Now that consumption is tracked (via update_curr()) we add support to throttle
group entities (and their corresponding cfs_rqs) in the case where this is no
run-time remaining.
Throttled entities are dequeued to prevent scheduling, additionally we mark
them as throttled (using cfs_rq->throttled) to prevent them from becoming
re-enqueued until they are unthrottled. A list of a task_group's throttled
entities are maintained on the cfs_bandwidth structure.
Note: While the machinery for throttling is added in this patch the act of
throttling an entity exceeding its bandwidth is deferred until later within
the series.
Signed-off-by: Paul Turner <pjt@google.com>
---
kernel/sched.c | 7 ++++
kernel/sched_fair.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 92 insertions(+), 4 deletions(-)
Index: tip/kernel/sched_fair.c
===================================================================
--- tip.orig/kernel/sched_fair.c
+++ tip/kernel/sched_fair.c
@@ -1313,7 +1313,8 @@ static void __refill_cfs_bandwidth_runti
cfs_b->runtime_expires = now + ktime_to_ns(cfs_b->period);
}
-static void assign_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+/* returns 0 on failure to allocate runtime */
+static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
struct task_group *tg = cfs_rq->tg;
struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
@@ -1354,6 +1355,8 @@ static void assign_cfs_rq_runtime(struct
*/
if ((s64)(expires - cfs_rq->runtime_expires) > 0)
cfs_rq->runtime_expires = expires;
+
+ return cfs_rq->runtime_remaining > 0;
}
/*
@@ -1403,7 +1406,53 @@ static void account_cfs_rq_runtime(struc
if (cfs_rq->runtime_remaining > 0)
return;
- assign_cfs_rq_runtime(cfs_rq);
+ /*
+ * if we're unable to extend our runtime we resched so that the active
+ * hierarchy can be throttled
+ */
+ if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
+ resched_task(rq_of(cfs_rq)->curr);
+}
+
+static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
+{
+ return cfs_rq->throttled;
+}
+
+static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
+{
+ struct rq *rq = rq_of(cfs_rq);
+ struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
+ struct sched_entity *se;
+ long task_delta, dequeue = 1;
+
+ se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];
+
+ /* account load preceding throttle */
+ update_cfs_load(cfs_rq, 0);
+
+ task_delta = cfs_rq->h_nr_running;
+ for_each_sched_entity(se) {
+ struct cfs_rq *qcfs_rq = cfs_rq_of(se);
+ /* throttled entity or throttle-on-deactivate */
+ if (!se->on_rq)
+ break;
+
+ if (dequeue)
+ dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
+ qcfs_rq->h_nr_running -= task_delta;
+
+ if (qcfs_rq->load.weight)
+ dequeue = 0;
+ }
+
+ if (!se)
+ rq->nr_running -= task_delta;
+
+ cfs_rq->throttled = 1;
+ raw_spin_lock(&cfs_b->lock);
+ list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
+ raw_spin_unlock(&cfs_b->lock);
}
/*
@@ -1440,6 +1489,11 @@ out_unlock:
#else
static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
unsigned long delta_exec) {}
+
+static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
+{
+ return 0;
+}
#endif
/**************************************************
@@ -1518,7 +1572,17 @@ enqueue_task_fair(struct rq *rq, struct
break;
cfs_rq = cfs_rq_of(se);
enqueue_entity(cfs_rq, se, flags);
+
+ /*
+ * end evaluation on encountering a throttled cfs_rq
+ *
+ * note: in the case of encountering a throttled cfs_rq we will
+ * post the final h_nr_running increment below.
+ */
+ if (cfs_rq_throttled(cfs_rq))
+ break;
cfs_rq->h_nr_running++;
+
flags = ENQUEUE_WAKEUP;
}
@@ -1526,11 +1590,15 @@ enqueue_task_fair(struct rq *rq, struct
cfs_rq = cfs_rq_of(se);
cfs_rq->h_nr_running++;
+ if (cfs_rq_throttled(cfs_rq))
+ break;
+
update_cfs_load(cfs_rq, 0);
update_cfs_shares(cfs_rq);
}
- inc_nr_running(rq);
+ if (!se)
+ inc_nr_running(rq);
hrtick_update(rq);
}
@@ -1550,6 +1618,15 @@ static void dequeue_task_fair(struct rq
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
dequeue_entity(cfs_rq, se, flags);
+
+ /*
+ * end evaluation on encountering a throttled cfs_rq
+ *
+ * note: in the case of encountering a throttled cfs_rq we will
+ * post the final h_nr_running decrement below.
+ */
+ if (cfs_rq_throttled(cfs_rq))
+ break;
cfs_rq->h_nr_running--;
/* Don't dequeue parent if it has other entities besides us */
@@ -1572,11 +1649,15 @@ static void dequeue_task_fair(struct rq
cfs_rq = cfs_rq_of(se);
cfs_rq->h_nr_running--;
+ if (cfs_rq_throttled(cfs_rq))
+ break;
+
update_cfs_load(cfs_rq, 0);
update_cfs_shares(cfs_rq);
}
- dec_nr_running(rq);
+ if (!se)
+ dec_nr_running(rq);
hrtick_update(rq);
}
Index: tip/kernel/sched.c
===================================================================
--- tip.orig/kernel/sched.c
+++ tip/kernel/sched.c
@@ -257,6 +257,8 @@ struct cfs_bandwidth {
int idle, timer_active;
struct hrtimer period_timer;
+ struct list_head throttled_cfs_rq;
+
#endif
};
@@ -396,6 +398,9 @@ struct cfs_rq {
int runtime_enabled;
u64 runtime_expires;
s64 runtime_remaining;
+
+ int throttled;
+ struct list_head throttled_list;
#endif
#endif
};
@@ -437,6 +442,7 @@ static void init_cfs_bandwidth(struct cf
cfs_b->quota = RUNTIME_INF;
cfs_b->period = ns_to_ktime(default_cfs_period());
+ INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
cfs_b->period_timer.function = sched_cfs_period_timer;
}
@@ -444,6 +450,7 @@ static void init_cfs_bandwidth(struct cf
static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
cfs_rq->runtime_enabled = 0;
+ INIT_LIST_HEAD(&cfs_rq->throttled_list);
}
/* requires cfs_b->lock, may release to reprogram timer */
next prev parent reply other threads:[~2011-07-07 5:33 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-07 5:30 [patch 00/17] CFS Bandwidth Control v7.1 Paul Turner
2011-07-07 5:30 ` [patch 01/17] sched: (fixlet) dont update shares twice on on_rq parent Paul Turner
2011-07-21 18:28 ` [tip:sched/core] sched: Don't " tip-bot for Paul Turner
2011-07-07 5:30 ` [patch 02/17] sched: hierarchical task accounting for SCHED_OTHER Paul Turner
2011-07-07 5:30 ` [patch 03/17] sched: introduce primitives to account for CFS bandwidth tracking Paul Turner
2011-07-07 13:48 ` Peter Zijlstra
2011-07-07 21:30 ` Paul Turner
2011-07-07 5:30 ` [patch 04/17] sched: validate CFS quota hierarchies Paul Turner
2011-07-07 5:30 ` [patch 05/17] sched: accumulate per-cfs_rq cpu usage and charge against bandwidth Paul Turner
2011-07-07 5:30 ` [patch 06/17] sched: add a timer to handle CFS bandwidth refresh Paul Turner
2011-07-07 5:30 ` [patch 07/17] sched: expire invalid runtime Paul Turner
2011-07-07 5:30 ` Paul Turner [this message]
2011-07-07 5:30 ` [patch 09/17] sched: add support for unthrottling group entities Paul Turner
2011-07-07 5:30 ` [patch 10/17] sched: allow for positional tg_tree walks Paul Turner
2011-07-07 5:30 ` [patch 11/17] sched: prevent interactions with throttled entities Paul Turner
2011-07-07 5:30 ` [patch 12/17] sched: prevent buddy " Paul Turner
2011-07-07 5:30 ` [patch 13/17] sched: migrate throttled tasks on HOTPLUG Paul Turner
2011-07-07 5:30 ` [patch 14/17] sched: throttle entities exceeding their allowed bandwidth Paul Turner
2011-07-07 5:30 ` [patch 15/17] sched: add exports tracking cfs bandwidth control statistics Paul Turner
2011-07-07 5:30 ` [patch 16/17] sched: return unused runtime on group dequeue Paul Turner
2011-07-07 5:30 ` [patch 17/17] sched: add documentation for bandwidth control Paul Turner
2011-07-07 11:13 ` [patch 00/17] CFS Bandwidth Control v7.1 Peter Zijlstra
2011-07-11 1:22 ` Hu Tao
2011-07-07 11:23 ` Ingo Molnar
2011-07-07 11:28 ` Peter Zijlstra
2011-07-07 14:38 ` Peter Zijlstra
2011-07-07 14:51 ` Ingo Molnar
2011-07-07 14:54 ` Peter Zijlstra
2011-07-07 14:56 ` Ingo Molnar
2011-07-07 16:23 ` Jason Baron
2011-07-07 17:20 ` Peter Zijlstra
2011-07-07 18:15 ` Jason Baron
2011-07-07 20:36 ` jump_label defaults (was Re: [patch 00/17] CFS Bandwidth Control v7.1) Peter Zijlstra
2011-07-08 9:20 ` Peter Zijlstra
2011-07-08 15:47 ` Jason Baron
2011-07-07 16:52 ` [patch 00/17] CFS Bandwidth Control v7.1 Andi Kleen
2011-07-07 17:08 ` Peter Zijlstra
2011-07-07 17:59 ` Peter Zijlstra
2011-07-07 19:36 ` Jason Baron
2011-07-08 7:45 ` Paul Turner
2011-07-08 7:39 ` Paul Turner
2011-07-08 10:32 ` Peter Zijlstra
2011-07-09 7:34 ` Paul Turner
2011-07-10 18:12 ` Ingo Molnar
2011-07-07 14:06 ` Peter Zijlstra
2011-07-08 7:35 ` Paul Turner
2011-07-11 1:22 ` Hu Tao
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