Re: [PATCH 08/35] autonuma: introduce kthread_bind_node()

Konrad Rzeszutek Wilk
2012-05-30T20:26:19Z

On Fri, May 25, 2012 at 07:02:12PM +0200, Andrea Arcangeli wrote:
> This function makes it easy to bind the per-node knuma_migrated
> threads to their respective NUMA nodes. Those threads take memory from
> the other nodes (in round robin with a incoming queue for each remote
> node) and they move that memory to their local node.
>
> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
> ---
> include/linux/kthread.h | 1 +
> kernel/kthread.c | 23 +++++++++++++++++++++++
> 2 files changed, 24 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/kthread.h b/include/linux/kthread.h
> index 0714b24..e733f97 100644
> --- a/include/linux/kthread.h
> +++ b/include/linux/kthread.h
> @@ -33,6 +33,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
> })
>
> void kthread_bind(struct task_struct *k, unsigned int cpu);
> +void kthread_bind_node(struct task_struct *p, int nid);
> int kthread_stop(struct task_struct *k);
> int kthread_should_stop(void);
> bool kthread_freezable_should_stop(bool *was_frozen);
> diff --git a/kernel/kthread.c b/kernel/kthread.c
> index 3d3de63..48b36f9 100644
> --- a/kernel/kthread.c
> +++ b/kernel/kthread.c
> @@ -234,6 +234,29 @@ void kthread_bind(struct task_struct *p, unsigned int cpu)
> EXPORT_SYMBOL(kthread_bind);
>
> /**
> + * kthread_bind_node - bind a just-created kthread to the CPUs of a node.
> + * @p: thread created by kthread_create().
> + * @nid: node (might not be online, must be possible) for @k to run on.
> + *
> + * Description: This function is equivalent to set_cpus_allowed(),
> + * except that @nid doesn't need to be online, and the thread must be
> + * stopped (i.e., just returned from kthread_create()).
> + */
> +void kthread_bind_node(struct task_struct *p, int nid)
> +{
> + /* Must have done schedule() in kthread() before we set_task_cpu */
> + if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) {
> + WARN_ON(1);
> + return;
> + }
> +
> + /* It's safe because the task is inactive. */
> + do_set_cpus_allowed(p, cpumask_of_node(nid));
> + p->flags |= PF_THREAD_BOUND;
> +}
> +EXPORT_SYMBOL(kthread_bind_node);

_GPL?

> +
> +/**
> * kthread_stop - stop a thread created by kthread_create().
> * @k: thread created by kthread_create().
> *
>
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