[GIT pull] scheduler fixes for 4.20

[Thomas Gleixner]

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

Two small scheduler fixes:

  - Take hotplug lock in sched_init_smp(). Technically not really required,
    but lockdep will complain other.

  - Trivial comment fix in sched/fair


Thanks,

        tglx

------------------>
Valentin Schneider (1):
      sched/core: Take the hotplug lock in sched_init_smp()

Yi Wang (1):
      sched/fair: Fix a comment in task_numa_fault()


 kernel/sched/core.c | 5 ++++-
 kernel/sched/fair.c | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fd2fce8a001b..02a20ef196a6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5859,11 +5859,14 @@ void __init sched_init_smp(void)
        /*
         * There's no userspace yet to cause hotplug operations; hence all the
         * CPU masks are stable and all blatant races in the below code cannot
-        * happen.
+        * happen. The hotplug lock is nevertheless taken to satisfy lockdep,
+        * but there won't be any contention on it.
         */
+       cpus_read_lock();
        mutex_lock(&sched_domains_mutex);
        sched_init_domains(cpu_active_mask);
        mutex_unlock(&sched_domains_mutex);
+       cpus_read_unlock();
 
        /* Move init over to a non-isolated CPU */
        if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) 
< 0)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ee271bb661cc..3648d0300fdf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2400,8 +2400,8 @@ void task_numa_fault(int last_cpupid, int mem_node, int 
pages, int flags)
                local = 1;
 
        /*
-        * Retry task to preferred node migration periodically, in case it
-        * case it previously failed, or the scheduler moved us.
+        * Retry to migrate task to preferred node periodically, in case it
+        * previously failed, or the scheduler moved us.
         */
        if (time_after(jiffies, p->numa_migrate_retry)) {
                task_numa_placement(p);