From e9f069868d60550c4b46f084ac9276a57c1b4711 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Fri, 4 Sep 2015 15:42:42 -0700 Subject: [PATCH] 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 Cc: Tejun Heo Cc: Eric Dumazet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kthread.h | 2 +- kernel/kthread.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 869b21d..e691b6a 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -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), diff --git a/kernel/kthread.c b/kernel/kthread.c index 490924c..9ff173d 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -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 -- 2.7.4