kernel/kthread.c: partial revert of 81c9886 ("kthread: ensure localit…

…y of task_struct allocations")

After discussions with Tejun, we don't want to spread the use of
cpu_to_mem() (and thus knowledge of allocators/NUMA topology details) into
callers, but would rather ensure the callees correctly handle memoryless
nodes.  With the previous patches ("topology: add support for
node_to_mem_node() to determine the fallback node" and "slub: fallback to
node_to_mem_node() node if allocating on memoryless node") adding and
using node_to_mem_node(), we can safely undo part of the change to the
kthread logic from 81c9886.

Signed-off-by: Nishanth Aravamudan <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Han Pingtian <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Anton Blanchard <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

kernel/kthread.c

@@ -369,7 +369,7 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
 {
 	struct task_struct *p;
 
-	p = kthread_create_on_node(threadfn, data, cpu_to_mem(cpu), namefmt,
+	p = kthread_create_on_node(threadfn, data, cpu_to_node(cpu), namefmt,
 				   cpu);
 	if (IS_ERR(p))
 		return p;