From: Gregory Haskins <ghaskins@novell.com>
To: mingo@elte.hu
Cc: rostedt@goodmis.org, ghaskins@novell.com,
linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 04/23] Subject: SCHED - RT overloaded runqueues accounting
Date: Tue, 04 Dec 2007 15:44:46 -0500 [thread overview]
Message-ID: <20071204204446.3567.35438.stgit@novell1.haskins.net> (raw)
In-Reply-To: <20071204204236.3567.65491.stgit@novell1.haskins.net>
From: Steven Rostedt <srostedt@redhat.com>
This patch adds an RT overload accounting system. When a runqueue has
more than one RT task queued, it is marked as overloaded. That is that it
is a candidate to have RT tasks pulled from it.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
---
kernel/sched_rt.c | 36 ++++++++++++++++++++++++++++++++++++
1 files changed, 36 insertions(+), 0 deletions(-)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index b5ef4b8..b8c758a 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -3,6 +3,38 @@
* policies)
*/
+#ifdef CONFIG_SMP
+static cpumask_t rt_overload_mask;
+static atomic_t rto_count;
+static inline int rt_overloaded(void)
+{
+ return atomic_read(&rto_count);
+}
+static inline cpumask_t *rt_overload(void)
+{
+ return &rt_overload_mask;
+}
+static inline void rt_set_overload(struct rq *rq)
+{
+ cpu_set(rq->cpu, rt_overload_mask);
+ /*
+ * Make sure the mask is visible before we set
+ * the overload count. That is checked to determine
+ * if we should look at the mask. It would be a shame
+ * if we looked at the mask, but the mask was not
+ * updated yet.
+ */
+ wmb();
+ atomic_inc(&rto_count);
+}
+static inline void rt_clear_overload(struct rq *rq)
+{
+ /* the order here really doesn't matter */
+ atomic_dec(&rto_count);
+ cpu_clear(rq->cpu, rt_overload_mask);
+}
+#endif /* CONFIG_SMP */
+
/*
* Update the current task's runtime statistics. Skip current tasks that
* are not in our scheduling class.
@@ -33,6 +65,8 @@ static inline void inc_rt_tasks(struct task_struct *p, struct rq *rq)
#ifdef CONFIG_SMP
if (p->prio < rq->rt.highest_prio)
rq->rt.highest_prio = p->prio;
+ if (rq->rt.rt_nr_running > 1)
+ rt_set_overload(rq);
#endif /* CONFIG_SMP */
}
@@ -54,6 +88,8 @@ static inline void dec_rt_tasks(struct task_struct *p, struct rq *rq)
} /* otherwise leave rq->highest prio alone */
} else
rq->rt.highest_prio = MAX_RT_PRIO;
+ if (rq->rt.rt_nr_running < 2)
+ rt_clear_overload(rq);
#endif /* CONFIG_SMP */
}
next prev parent reply other threads:[~2007-12-04 21:08 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-04 20:44 [PATCH 00/23] RT balance v7 Gregory Haskins
2007-12-04 20:44 ` [PATCH 01/23] Subject: SCHED - Add rt_nr_running accounting Gregory Haskins
2007-12-04 20:44 ` [PATCH 02/23] Subject: SCHED - track highest prio queued on runqueue Gregory Haskins
2007-12-04 20:44 ` [PATCH 03/23] Subject: SCHED - push RT tasks Gregory Haskins
2007-12-04 20:44 ` Gregory Haskins [this message]
2007-12-04 20:44 ` [PATCH 05/23] Subject: SCHED - pull " Gregory Haskins
2007-12-04 20:44 ` [PATCH 06/23] Subject: SCHED - wake up balance RT Gregory Haskins
2007-12-04 20:45 ` [PATCH 07/23] Subject: SCHED - disable CFS RT load balancing Gregory Haskins
2007-12-04 20:45 ` [PATCH 08/23] Subject: SCHED - Cache cpus_allowed weight for optimizing migration Gregory Haskins
2007-12-04 20:45 ` [PATCH 09/23] Subject: SCHED - Consistency cleanup for this_rq usage Gregory Haskins
2007-12-04 20:45 ` [PATCH 10/23] Subject: SCHED - Remove some CFS specific code from the wakeup path of RT tasks Gregory Haskins
2007-12-04 20:45 ` [PATCH 11/23] Subject: SCHED - Break out the search function Gregory Haskins
2007-12-04 20:45 ` [PATCH 12/23] Subject: SCHED - Allow current_cpu to be included in search Gregory Haskins
2007-12-04 20:45 ` [PATCH 13/23] Subject: SCHED - Pre-route RT tasks on wakeup Gregory Haskins
2007-12-04 20:45 ` [PATCH 14/23] Subject: SCHED - Optimize our cpu selection based on topology Gregory Haskins
2007-12-04 20:45 ` [PATCH 15/23] Subject: SCHED - Optimize rebalancing Gregory Haskins
2007-12-04 20:45 ` [PATCH 16/23] Subject: SCHED - Avoid overload Gregory Haskins
2007-12-04 20:45 ` [PATCH 17/23] Subject: SCHED - restore the migratable conditional Gregory Haskins
2007-12-04 20:45 ` [PATCH 18/23] Subject: SCHED - Optimize cpu search with hamming weight Gregory Haskins
2007-12-04 20:46 ` [PATCH 19/23] Subject: SCHED - Optimize out cpu_clears Gregory Haskins
2007-12-04 20:46 ` [PATCH 20/23] Subject: SCHED - balance RT tasks no new wake up Gregory Haskins
2007-12-04 20:46 ` [PATCH 21/23] Subject: SCHED - Add sched-domain roots Gregory Haskins
2007-12-04 20:46 ` [PATCH 22/23] Subject: SCHED - Only balance our RT tasks within our root-domain Gregory Haskins
2007-12-04 20:46 ` [PATCH 23/23] Subject: SCHED - Use a 2-d bitmap for searching lowest-pri CPU Gregory Haskins
2007-12-04 21:27 ` [PATCH 00/23] RT balance v7 Ingo Molnar
2007-12-04 21:35 ` Gregory Haskins
2007-12-05 2:55 ` [PATCH 0/3] RT balance v7a Gregory Haskins
2007-12-05 2:55 ` [PATCH 1/3] Subject: SCHED - Add sched-domain roots Gregory Haskins
2007-12-05 2:55 ` [PATCH 2/3] Subject: SCHED - Only balance our RT tasks within our root-domain Gregory Haskins
2007-12-05 2:55 ` [PATCH 3/3] Subject: SCHED - Use a 2-d bitmap for searching lowest-pri CPU Gregory Haskins
2007-12-05 9:34 ` Ingo Molnar
2007-12-05 10:19 ` Gregory Haskins
2007-12-05 11:44 ` Ingo Molnar
2007-12-05 13:41 ` Gregory Haskins
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