rcu: Use kthread_create_on_node()

Commit a26ac2455ffc (move TREE_RCU from softirq to kthread) added
per-CPU kthreads.  However, kthread creation uses kthread_create(), which
can put the kthread's stack and task struct on the wrong NUMA node.
Therefore, use kthread_create_on_node() instead of kthread_create()
so that the stacks and task structs are placed on the correct NUMA node.

A similar change was carried out in commit 94dcf29a11b3 (kthread:
use kthread_create_on_node()).

Also change rcutorture's priority-boost-test kthread creation.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tejun Heo <tj@kernel.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Andi Kleen <ak@linux.intel.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 98f51b13bb7ec659b3a40f22a4f52b7bb62dfae3..1d24150461545c8c3047b3cef8f92649310eee43 100644 (file)
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -1280,8 +1280,9 @@ static int rcutorture_booster_init(int cpu)
        /* Don't allow time recalculation while creating a new task. */
        mutex_lock(&boost_mutex);
        VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task");
-       boost_tasks[cpu] = kthread_create(rcu_torture_boost, NULL,
-                                         "rcu_torture_boost");
+       boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
+                                                 cpu_to_node(cpu),
+                                                 "rcu_torture_boost");
        if (IS_ERR(boost_tasks[cpu])) {
                retval = PTR_ERR(boost_tasks[cpu]);
                VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed");

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 8aafbb80b8b093e1072f2fcc4dc66bf40f249b7f..7b850cdc0aee8519510f1d4eb25621dea7f07e91 100644 (file)
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1560,7 +1560,10 @@ static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu)
        if (!rcu_scheduler_fully_active ||
            per_cpu(rcu_cpu_kthread_task, cpu) != NULL)
                return 0;
-       t = kthread_create(rcu_cpu_kthread, (void *)(long)cpu, "rcuc%d", cpu);
+       t = kthread_create_on_node(rcu_cpu_kthread,
+                                  (void *)(long)cpu,
+                                  cpu_to_node(cpu),
+                                  "rcuc%d", cpu);
        if (IS_ERR(t))
                return PTR_ERR(t);
        if (cpu_online(cpu))