Commit f4efdd65 authored by Linus Torvalds's avatar Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  work_on_cpu(): rewrite it to create a kernel thread on demand
  kthread: move sched-realeted initialization from kthreadd context
  kthread: Don't looking for a task in create_kthread() #2
parents d8312204 6b44003e
...@@ -76,6 +76,7 @@ static int kthread(void *_create) ...@@ -76,6 +76,7 @@ static int kthread(void *_create)
/* OK, tell user we're spawned, wait for stop or wakeup */ /* OK, tell user we're spawned, wait for stop or wakeup */
__set_current_state(TASK_UNINTERRUPTIBLE); __set_current_state(TASK_UNINTERRUPTIBLE);
create->result = current;
complete(&create->started); complete(&create->started);
schedule(); schedule();
...@@ -96,22 +97,10 @@ static void create_kthread(struct kthread_create_info *create) ...@@ -96,22 +97,10 @@ static void create_kthread(struct kthread_create_info *create)
/* We want our own signal handler (we take no signals by default). */ /* We want our own signal handler (we take no signals by default). */
pid = kernel_thread(kthread, create, CLONE_FS | CLONE_FILES | SIGCHLD); pid = kernel_thread(kthread, create, CLONE_FS | CLONE_FILES | SIGCHLD);
if (pid < 0) { if (pid < 0)
create->result = ERR_PTR(pid); create->result = ERR_PTR(pid);
} else { else
struct sched_param param = { .sched_priority = 0 };
wait_for_completion(&create->started); wait_for_completion(&create->started);
read_lock(&tasklist_lock);
create->result = find_task_by_pid_ns(pid, &init_pid_ns);
read_unlock(&tasklist_lock);
/*
* root may have changed our (kthreadd's) priority or CPU mask.
* The kernel thread should not inherit these properties.
*/
sched_setscheduler(create->result, SCHED_NORMAL, &param);
set_user_nice(create->result, KTHREAD_NICE_LEVEL);
set_cpus_allowed_ptr(create->result, cpu_all_mask);
}
complete(&create->done); complete(&create->done);
} }
...@@ -154,11 +143,20 @@ struct task_struct *kthread_create(int (*threadfn)(void *data), ...@@ -154,11 +143,20 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
wait_for_completion(&create.done); wait_for_completion(&create.done);
if (!IS_ERR(create.result)) { if (!IS_ERR(create.result)) {
struct sched_param param = { .sched_priority = 0 };
va_list args; va_list args;
va_start(args, namefmt); va_start(args, namefmt);
vsnprintf(create.result->comm, sizeof(create.result->comm), vsnprintf(create.result->comm, sizeof(create.result->comm),
namefmt, args); namefmt, args);
va_end(args); va_end(args);
/*
* root may have changed our (kthreadd's) priority or CPU mask.
* The kernel thread should not inherit these properties.
*/
sched_setscheduler_nocheck(create.result, SCHED_NORMAL, &param);
set_user_nice(create.result, KTHREAD_NICE_LEVEL);
set_cpus_allowed_ptr(create.result, cpu_all_mask);
} }
return create.result; return create.result;
} }
......
...@@ -966,20 +966,20 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, ...@@ -966,20 +966,20 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
} }
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
static struct workqueue_struct *work_on_cpu_wq __read_mostly;
struct work_for_cpu { struct work_for_cpu {
struct work_struct work; struct completion completion;
long (*fn)(void *); long (*fn)(void *);
void *arg; void *arg;
long ret; long ret;
}; };
static void do_work_for_cpu(struct work_struct *w) static int do_work_for_cpu(void *_wfc)
{ {
struct work_for_cpu *wfc = container_of(w, struct work_for_cpu, work); struct work_for_cpu *wfc = _wfc;
wfc->ret = wfc->fn(wfc->arg); wfc->ret = wfc->fn(wfc->arg);
complete(&wfc->completion);
return 0;
} }
/** /**
...@@ -990,17 +990,23 @@ static void do_work_for_cpu(struct work_struct *w) ...@@ -990,17 +990,23 @@ static void do_work_for_cpu(struct work_struct *w)
* *
* This will return the value @fn returns. * This will return the value @fn returns.
* It is up to the caller to ensure that the cpu doesn't go offline. * It is up to the caller to ensure that the cpu doesn't go offline.
* The caller must not hold any locks which would prevent @fn from completing.
*/ */
long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg) long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
{ {
struct work_for_cpu wfc; struct task_struct *sub_thread;
struct work_for_cpu wfc = {
INIT_WORK(&wfc.work, do_work_for_cpu); .completion = COMPLETION_INITIALIZER_ONSTACK(wfc.completion),
wfc.fn = fn; .fn = fn,
wfc.arg = arg; .arg = arg,
queue_work_on(cpu, work_on_cpu_wq, &wfc.work); };
flush_work(&wfc.work);
sub_thread = kthread_create(do_work_for_cpu, &wfc, "work_for_cpu");
if (IS_ERR(sub_thread))
return PTR_ERR(sub_thread);
kthread_bind(sub_thread, cpu);
wake_up_process(sub_thread);
wait_for_completion(&wfc.completion);
return wfc.ret; return wfc.ret;
} }
EXPORT_SYMBOL_GPL(work_on_cpu); EXPORT_SYMBOL_GPL(work_on_cpu);
...@@ -1016,8 +1022,4 @@ void __init init_workqueues(void) ...@@ -1016,8 +1022,4 @@ void __init init_workqueues(void)
hotcpu_notifier(workqueue_cpu_callback, 0); hotcpu_notifier(workqueue_cpu_callback, 0);
keventd_wq = create_workqueue("events"); keventd_wq = create_workqueue("events");
BUG_ON(!keventd_wq); BUG_ON(!keventd_wq);
#ifdef CONFIG_SMP
work_on_cpu_wq = create_workqueue("work_on_cpu");
BUG_ON(!work_on_cpu_wq);
#endif
} }
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment