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authorPeter Boonstoppel <pboonstoppel@nvidia.com>2012-08-09 15:34:47 -0700
committerBen Hutchings <ben@decadent.org.uk>2014-02-15 19:20:18 +0000
commit4553dab7f3e57b70fee61739325b6ff7bb56ac9b (patch)
tree3f9255343b491e04889c9711ce262872bbed84c1
parentaee1f8b87e203b0525f340d2fde94f5a82f6c4bd (diff)
sched: Unthrottle rt runqueues in __disable_runtime()
commit a4c96ae319b8047f62dedbe1eac79e321c185749 upstream. migrate_tasks() uses _pick_next_task_rt() to get tasks from the real-time runqueues to be migrated. When rt_rq is throttled _pick_next_task_rt() won't return anything, in which case migrate_tasks() can't move all threads over and gets stuck in an infinite loop. Instead unthrottle rt runqueues before migrating tasks. Additionally: move unthrottle_offline_cfs_rqs() to rq_offline_fair() Signed-off-by: Peter Boonstoppel <pboonstoppel@nvidia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/5FBF8E85CA34454794F0F7ECBA79798F379D3648B7@HQMAIL04.nvidia.com Signed-off-by: Ingo Molnar <mingo@kernel.org> [ lizf: backported to 3.4: adjust context ] Signed-off-by: Li Zefan <lizefan@huawei.com> [bwh: Backported to 3.2: - Adjust filenames - unthrottle_offline_cfs_rqs() is already static, but defined in sched.c after including sched_fair.c, so add forward declaration - unthrottle_offline_cfs_rqs() also needs to be defined for all CONFIG_SMP configurations now] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--kernel/sched.c13
-rw-r--r--kernel/sched_fair.c3
-rw-r--r--kernel/sched_rt.c1
3 files changed, 12 insertions, 5 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index d93369a977d1..ea85b0d2bbf2 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2189,6 +2189,10 @@ static int irqtime_account_si_update(void)
#endif
+#ifdef CONFIG_SMP
+static void unthrottle_offline_cfs_rqs(struct rq *rq);
+#endif
+
#include "sched_idletask.c"
#include "sched_fair.c"
#include "sched_rt.c"
@@ -6566,8 +6570,6 @@ static void unthrottle_offline_cfs_rqs(struct rq *rq)
unthrottle_cfs_rq(cfs_rq);
}
}
-#else
-static void unthrottle_offline_cfs_rqs(struct rq *rq) {}
#endif
/*
@@ -6595,9 +6597,6 @@ static void migrate_tasks(unsigned int dead_cpu)
*/
rq->stop = NULL;
- /* Ensure any throttled groups are reachable by pick_next_task */
- unthrottle_offline_cfs_rqs(rq);
-
for ( ; ; ) {
/*
* There's this thread running, bail when that's the only
@@ -6624,6 +6623,10 @@ static void migrate_tasks(unsigned int dead_cpu)
#endif /* CONFIG_HOTPLUG_CPU */
+#if !defined(CONFIG_HOTPLUG_CPU) || !defined(CONFIG_CFS_BANDWIDTH)
+static void unthrottle_offline_cfs_rqs(struct rq *rq) {}
+#endif
+
#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
static struct ctl_table sd_ctl_dir[] = {
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5b9e456ea98c..37f3f3925d3d 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -4848,6 +4848,9 @@ static void rq_online_fair(struct rq *rq)
static void rq_offline_fair(struct rq *rq)
{
update_sysctl();
+
+ /* Ensure any throttled groups are reachable by pick_next_task */
+ unthrottle_offline_cfs_rqs(rq);
}
#else /* CONFIG_SMP */
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index d0fff8139377..2992f93b68cb 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -509,6 +509,7 @@ balanced:
* runtime - in which case borrowing doesn't make sense.
*/
rt_rq->rt_runtime = RUNTIME_INF;
+ rt_rq->rt_throttled = 0;
raw_spin_unlock(&rt_rq->rt_runtime_lock);
raw_spin_unlock(&rt_b->rt_runtime_lock);
}