Commit e9f06986 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

kernel/kthread.c:kthread_create_on_node(): clarify documentation 



- Make it clear that the `node' arg refers to memory allocations only:
  kthread_create_on_node() does not pin the new thread to that node's
  CPUs.

- Encourage the use of NUMA_NO_NODE.

[nzimmer@sgi.com: use NUMA_NO_NODE in kthread_create() also]
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 04697858

include/linux/kthread.h

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), 
					   const char namefmt[], ...);



#define kthread_create(threadfn, data, namefmt, arg...) \

	kthread_create_on_node(threadfn, data, -1, namefmt, ##arg)

	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)





struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),

kernel/kthread.c

+4 −3
Original line number Diff line number Diff line
@@ -248,15 +248,16 @@ static void create_kthread(struct kthread_create_info *create) 
 * 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.

 * @node: task and thread structures for the thread are allocated on this node

 * @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().

 * it.  See also kthread_run().  The new thread has SCHED_NORMAL policy and

 * is affine to all CPUs.

 *

 * 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.

 * in @node, to get NUMA affinity for kthread stack, or else give NUMA_NO_NODE.

 * 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 no one will call kthread_stop(), or

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