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[2/5,Trusty,SRU] kthread: ensure locality of task_struct allocations

Message ID 1403185111-128994-2-git-send-email-tim.gardner@canonical.com
State New
Headers show

Commit Message

Tim Gardner June 19, 2014, 1:38 p.m. UTC 
From: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1332063

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>
(cherry picked from commit 81c98869faa5f3a9457c93efef908ef476326b31)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 kernel/kthread.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 52ae7dc..ca921a3 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -217,7 +217,7 @@  int tsk_fork_get_node(struct task_struct *tsk)
 	if (tsk == kthreadd_task)
 		return tsk->pref_node_fork;
 #endif
-	return numa_node_id();
+	return NUMA_NO_NODE;
 }
 
 static void create_kthread(struct kthread_create_info *create)
@@ -381,7 +381,7 @@  struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
 {
 	struct task_struct *p;
 
-	p = kthread_create_on_node(threadfn, data, cpu_to_node(cpu), namefmt,
+	p = kthread_create_on_node(threadfn, data, cpu_to_mem(cpu), namefmt,
 				   cpu);
 	if (IS_ERR(p))
 		return p;