From 207205a2ba2655652fe46a60b49838af6c16a919 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 22 Mar 2011 16:30:44 -0700 Subject: 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 Acked-by: David S. Miller Reviewed-by: Andi Kleen Acked-by: Rusty Russell Cc: Tejun Heo Cc: Tony Luck Cc: Fenghua Yu Cc: David Howells Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kthread.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) (limited to 'kernel/kthread.c') diff --git a/kernel/kthread.c b/kernel/kthread.c index c55afba990a..684ab3f7dd7 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. -- cgit v1.2.3