kthread: ensure locality of task_struct allocations

In the presence of memoryless nodes, numa_node_id() will return the
current CPU's NUMA node, but that may not be where we expect to allocate
from memory from.  Instead, we should rely on the fallback code in the
memory allocator itself, by using NUMA_NO_NODE.  Also, when calling
kthread_create_on_node(), use the nearest node with memory to the cpu in
question, rather than the node it is running on.

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
kthread: fix return value of kthread_create() upon SIGKILL.

Commit ("kthread: make kthread_create() killable") meant
for allowing kthread_create() to abort as soon as killed by the
OOM-killer.  But returning -ENOMEM is wrong if killed by SIGKILL from
userspace.  Change kthread_create() to return -EINTR upon SIGKILL.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [3.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>