[GIT PULL] scheduler fixes

Ingo Molnar
2017-12-15T15:35:33Z

Linus,

Please pull the latest sched-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus

# HEAD: f73c52a5bcd1710994e53fbccc378c42b97a06b6 sched/rt: Do not pull from current CPU if only one CPU to pull

Two fixes: a crash fix for an ARM SoC platform, and kernel-doc warnings fixes.

Thanks,

Ingo

------------------>
Randy Dunlap (1):
sched/core: Fix kernel-doc warnings after code movement

Steven Rostedt (1):
sched/rt: Do not pull from current CPU if only one CPU to pull

kernel/sched/core.c | 22 +++++++++++-----------
kernel/sched/rt.c | 8 +++++++-
2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 75554f366fd3..644fa2e3d993 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5097,17 +5097,6 @@ SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
return ret;
}

-/**
- * sys_sched_rr_get_interval - return the default timeslice of a process.
- * @pid: pid of the process.
- * @interval: userspace pointer to the timeslice value.
- *
- * this syscall writes the default timeslice value of a given process
- * into the user-space timespec buffer. A value of '0' means infinity.
- *
- * Return: On success, 0 and the timeslice is in @interval. Otherwise,
- * an error code.
- */
static int sched_rr_get_interval(pid_t pid, struct timespec64 *t)
{
struct task_struct *p;
@@ -5144,6 +5133,17 @@ static int sched_rr_get_interval(pid_t pid, struct timespec64 *t)
return retval;
}

+/**
+ * sys_sched_rr_get_interval - return the default timeslice of a process.
+ * @pid: pid of the process.
+ * @interval: userspace pointer to the timeslice value.
+ *
+ * this syscall writes the default timeslice value of a given process
+ * into the user-space timespec buffer. A value of '0' means infinity.
+ *
+ * Return: On success, 0 and the timeslice is in @interval. Otherwise,
+ * an error code.
+ */
SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
struct timespec __user *, interval)
{
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 4056c19ca3f0..665ace2fc558 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2034,8 +2034,9 @@ static void pull_rt_task(struct rq *this_rq)
bool resched = false;
struct task_struct *p;
struct rq *src_rq;
+ int rt_overload_count = rt_overloaded(this_rq);

- if (likely(!rt_overloaded(this_rq)))
+ if (likely(!rt_overload_count))
return;

/*
@@ -2044,6 +2045,11 @@ static void pull_rt_task(struct rq *this_rq)
*/
smp_rmb();

+ /* If we are the only overloaded CPU do nothing */
+ if (rt_overload_count == 1 &&
+ cpumask_test_cpu(this_rq->cpu, this_rq->rd->rto_mask))
+ return;
+
#ifdef HAVE_RT_PUSH_IPI
if (sched_feat(RT_PUSH_IPI)) {
tell_cpu_to_push(this_rq);