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: 301a5cba2887d1f640e6d5184b05a6d7132017d5 sched: Update 
sched_domains_numa_masks[][] when new cpus are onlined

A CPU hotplug related crash fix and a nohz accounting fixlet.

 Thanks,

        Ingo

------------------>
Frederic Weisbecker (1):
      nohz: Fix one jiffy count too far in idle cputime

Tang Chen (2):
      sched: Ensure 'sched_domains_numa_levels' is safe to use in other 
functions
      sched: Update sched_domains_numa_masks[][] when new cpus are onlined


 kernel/sched/core.c      | 69 ++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/time/tick-sched.c |  2 +-
 2 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c177472..8322d73 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6122,6 +6122,17 @@ static void sched_init_numa(void)
         * numbers.
         */
 
+       /*
+        * Here, we should temporarily reset sched_domains_numa_levels to 0.
+        * If it fails to allocate memory for array 
sched_domains_numa_masks[][],
+        * the array will contain less then 'level' members. This could be
+        * dangerous when we use it to iterate array 
sched_domains_numa_masks[][]
+        * in other functions.
+        *
+        * We reset it to 'level' at the end of this function.
+        */
+       sched_domains_numa_levels = 0;
+
        sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL);
        if (!sched_domains_numa_masks)
                return;
@@ -6176,11 +6187,68 @@ static void sched_init_numa(void)
        }
 
        sched_domain_topology = tl;
+
+       sched_domains_numa_levels = level;
+}
+
+static void sched_domains_numa_masks_set(int cpu)
+{
+       int i, j;
+       int node = cpu_to_node(cpu);
+
+       for (i = 0; i < sched_domains_numa_levels; i++) {
+               for (j = 0; j < nr_node_ids; j++) {
+                       if (node_distance(j, node) <= 
sched_domains_numa_distance[i])
+                               cpumask_set_cpu(cpu, 
sched_domains_numa_masks[i][j]);
+               }
+       }
+}
+
+static void sched_domains_numa_masks_clear(int cpu)
+{
+       int i, j;
+       for (i = 0; i < sched_domains_numa_levels; i++) {
+               for (j = 0; j < nr_node_ids; j++)
+                       cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]);
+       }
+}
+
+/*
+ * Update sched_domains_numa_masks[level][node] array when new cpus
+ * are onlined.
+ */
+static int sched_domains_numa_masks_update(struct notifier_block *nfb,
+                                          unsigned long action,
+                                          void *hcpu)
+{
+       int cpu = (long)hcpu;
+
+       switch (action & ~CPU_TASKS_FROZEN) {
+       case CPU_ONLINE:
+               sched_domains_numa_masks_set(cpu);
+               break;
+
+       case CPU_DEAD:
+               sched_domains_numa_masks_clear(cpu);
+               break;
+
+       default:
+               return NOTIFY_DONE;
+       }
+
+       return NOTIFY_OK;
 }
 #else
 static inline void sched_init_numa(void)
 {
 }
+
+static int sched_domains_numa_masks_update(struct notifier_block *nfb,
+                                          unsigned long action,
+                                          void *hcpu)
+{
+       return 0;
+}
 #endif /* CONFIG_NUMA */
 
 static int __sdt_alloc(const struct cpumask *cpu_map)
@@ -6629,6 +6697,7 @@ void __init sched_init_smp(void)
        mutex_unlock(&sched_domains_mutex);
        put_online_cpus();
 
+       hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE);
        hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
        hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index f423bdd..a402608 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -835,7 +835,7 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer 
*timer)
                 */
                if (ts->tick_stopped) {
                        touch_softlockup_watchdog();
-                       if (idle_cpu(cpu))
+                       if (is_idle_task(current))
                                ts->idle_jiffies++;
                }
                update_process_times(user_mode(regs));
--
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