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authorEric Dumazet <eric.dumazet@gmail.com>2011-03-22 16:30:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-22 17:44:01 -0700
commit207205a2ba2655652fe46a60b49838af6c16a919 (patch)
tree4309aa7cd5cf39c805219001e0ed8ec5b71e4d5e /kernel/kthread.c
parentb6a84016bd2598e35ead635147fa53619982648d (diff)
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kthread: NUMA aware kthread_create_on_node()
All kthreads being created from a single helper task, they all use memory from a single node for their kernel stack and task struct. This patch suite creates kthread_create_on_node(), adding a 'cpu' parameter to parameters already used by kthread_create(). This parameter serves in allocating memory for the new kthread on its memory node if possible. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/kthread.c')
-rw-r--r--kernel/kthread.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c
index c55afba990a3..684ab3f7dd72 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -27,6 +27,7 @@ struct kthread_create_info
/* Information passed to kthread() from kthreadd. */
int (*threadfn)(void *data);
void *data;
+ int node;
/* Result passed back to kthread_create() from kthreadd. */
struct task_struct *result;
@@ -98,10 +99,23 @@ static int kthread(void *_create)
do_exit(ret);
}
+/* called from do_fork() to get node information for about to be created task */
+int tsk_fork_get_node(struct task_struct *tsk)
+{
+#ifdef CONFIG_NUMA
+ if (tsk == kthreadd_task)
+ return tsk->pref_node_fork;
+#endif
+ return numa_node_id();
+}
+
static void create_kthread(struct kthread_create_info *create)
{
int pid;
+#ifdef CONFIG_NUMA
+ current->pref_node_fork = create->node;
+#endif
/* We want our own signal handler (we take no signals by default). */
pid = kernel_thread(kthread, create, CLONE_FS | CLONE_FILES | SIGCHLD);
if (pid < 0) {
@@ -111,15 +125,18 @@ static void create_kthread(struct kthread_create_info *create)
}
/**
- * kthread_create - create a kthread.
+ * kthread_create_on_node - create a kthread.
* @threadfn: the function to run until signal_pending(current).
* @data: data ptr for @threadfn.
+ * @node: memory node number.
* @namefmt: printf-style name for the thread.
*
* Description: This helper function creates and names a kernel
* thread. The thread will be stopped: use wake_up_process() to start
* it. See also kthread_run().
*
+ * If thread is going to be bound on a particular cpu, give its node
+ * in @node, to get NUMA affinity for kthread stack, or else give -1.
* When woken, the thread will run @threadfn() with @data as its
* argument. @threadfn() can either call do_exit() directly if it is a
* standalone thread for which noone will call kthread_stop(), or
@@ -129,15 +146,17 @@ static void create_kthread(struct kthread_create_info *create)
*
* Returns a task_struct or ERR_PTR(-ENOMEM).
*/
-struct task_struct *kthread_create(int (*threadfn)(void *data),
- void *data,
- const char namefmt[],
- ...)
+struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
+ void *data,
+ int node,
+ const char namefmt[],
+ ...)
{
struct kthread_create_info create;
create.threadfn = threadfn;
create.data = data;
+ create.node = node;
init_completion(&create.done);
spin_lock(&kthread_create_lock);
@@ -164,7 +183,7 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
}
return create.result;
}
-EXPORT_SYMBOL(kthread_create);
+EXPORT_SYMBOL(kthread_create_on_node);
/**
* kthread_bind - bind a just-created kthread to a cpu.