From 207205a2ba2655652fe46a60b49838af6c16a919 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 22 Mar 2011 16:30:44 -0700 Subject: [PATCH] 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 --- include/linux/kthread.h | 14 ++++++++++---- include/linux/sched.h | 1 + kernel/fork.c | 3 ++- kernel/kthread.c | 31 +++++++++++++++++++++++++------ 4 files changed, 38 insertions(+), 11 deletions(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 7ff16f7..1e923e5 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -4,10 +4,15 @@ #include #include -struct task_struct *kthread_create(int (*threadfn)(void *data), - void *data, - const char namefmt[], ...) - __attribute__((format(printf, 3, 4))); +struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), + void *data, + int node, + const char namefmt[], ...) + __attribute__((format(printf, 4, 5))); + +#define kthread_create(threadfn, data, namefmt, arg...) \ + kthread_create_on_node(threadfn, data, -1, namefmt, ##arg) + /** * kthread_run - create and wake a thread. @@ -34,6 +39,7 @@ void *kthread_data(struct task_struct *k); int kthreadd(void *unused); extern struct task_struct *kthreadd_task; +extern int tsk_fork_get_node(struct task_struct *tsk); /* * Simple work processor based on kthread. diff --git a/include/linux/sched.h b/include/linux/sched.h index c15936f..4b601be 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1471,6 +1471,7 @@ struct task_struct { #ifdef CONFIG_NUMA struct mempolicy *mempolicy; /* Protected by alloc_lock */ short il_next; + short pref_node_fork; #endif atomic_t fs_excl; /* holding fs exclusive resources */ struct rcu_head rcu; diff --git a/kernel/fork.c b/kernel/fork.c index cbc6adc..a8f64f8e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -254,7 +255,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) struct task_struct *tsk; struct thread_info *ti; unsigned long *stackend; - int node = numa_node_id(); + int node = tsk_fork_get_node(orig); int err; prepare_to_copy(orig); diff --git a/kernel/kthread.c b/kernel/kthread.c index c55afba..684ab3f 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. -- 2.7.4