Commit 207205a2 authored by Eric Dumazet's avatar Eric Dumazet Committed by Linus Torvalds

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: default avatarEric Dumazet <eric.dumazet@gmail.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b6a84016
......@@ -4,10 +4,15 @@
#include <linux/err.h>
#include <linux/sched.h>
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.
......
......@@ -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;
......
......@@ -40,6 +40,7 @@
#include <linux/tracehook.h>
#include <linux/futex.h>
#include <linux/compat.h>
#include <linux/kthread.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/rcupdate.h>
#include <linux/ptrace.h>
......@@ -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);
......
......@@ -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.
......
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