mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 22:36:40 +07:00
c1a220e7ac
This interface allows adding a job on a specific cpu. Although a work struct on a cpu will be scheduled to other cpu if the cpu dies, there is a recursion if a work task tries to offline the cpu it's running on. we need to schedule the task to a specific cpu in this case. http://bugzilla.kernel.org/show_bug.cgi?id=10897 [oleg@tv-sign.ru: cleanups] Signed-off-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Rus <harbour@sfinx.od.ua> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
918 lines
22 KiB
C
918 lines
22 KiB
C
/*
|
|
* linux/kernel/workqueue.c
|
|
*
|
|
* Generic mechanism for defining kernel helper threads for running
|
|
* arbitrary tasks in process context.
|
|
*
|
|
* Started by Ingo Molnar, Copyright (C) 2002
|
|
*
|
|
* Derived from the taskqueue/keventd code by:
|
|
*
|
|
* David Woodhouse <dwmw2@infradead.org>
|
|
* Andrew Morton <andrewm@uow.edu.au>
|
|
* Kai Petzke <wpp@marie.physik.tu-berlin.de>
|
|
* Theodore Ts'o <tytso@mit.edu>
|
|
*
|
|
* Made to use alloc_percpu by Christoph Lameter.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/init.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/kthread.h>
|
|
#include <linux/hardirq.h>
|
|
#include <linux/mempolicy.h>
|
|
#include <linux/freezer.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/debug_locks.h>
|
|
#include <linux/lockdep.h>
|
|
|
|
/*
|
|
* The per-CPU workqueue (if single thread, we always use the first
|
|
* possible cpu).
|
|
*/
|
|
struct cpu_workqueue_struct {
|
|
|
|
spinlock_t lock;
|
|
|
|
struct list_head worklist;
|
|
wait_queue_head_t more_work;
|
|
struct work_struct *current_work;
|
|
|
|
struct workqueue_struct *wq;
|
|
struct task_struct *thread;
|
|
|
|
int run_depth; /* Detect run_workqueue() recursion depth */
|
|
} ____cacheline_aligned;
|
|
|
|
/*
|
|
* The externally visible workqueue abstraction is an array of
|
|
* per-CPU workqueues:
|
|
*/
|
|
struct workqueue_struct {
|
|
struct cpu_workqueue_struct *cpu_wq;
|
|
struct list_head list;
|
|
const char *name;
|
|
int singlethread;
|
|
int freezeable; /* Freeze threads during suspend */
|
|
#ifdef CONFIG_LOCKDEP
|
|
struct lockdep_map lockdep_map;
|
|
#endif
|
|
};
|
|
|
|
/* Serializes the accesses to the list of workqueues. */
|
|
static DEFINE_SPINLOCK(workqueue_lock);
|
|
static LIST_HEAD(workqueues);
|
|
|
|
static int singlethread_cpu __read_mostly;
|
|
static cpumask_t cpu_singlethread_map __read_mostly;
|
|
/*
|
|
* _cpu_down() first removes CPU from cpu_online_map, then CPU_DEAD
|
|
* flushes cwq->worklist. This means that flush_workqueue/wait_on_work
|
|
* which comes in between can't use for_each_online_cpu(). We could
|
|
* use cpu_possible_map, the cpumask below is more a documentation
|
|
* than optimization.
|
|
*/
|
|
static cpumask_t cpu_populated_map __read_mostly;
|
|
|
|
/* If it's single threaded, it isn't in the list of workqueues. */
|
|
static inline int is_single_threaded(struct workqueue_struct *wq)
|
|
{
|
|
return wq->singlethread;
|
|
}
|
|
|
|
static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq)
|
|
{
|
|
return is_single_threaded(wq)
|
|
? &cpu_singlethread_map : &cpu_populated_map;
|
|
}
|
|
|
|
static
|
|
struct cpu_workqueue_struct *wq_per_cpu(struct workqueue_struct *wq, int cpu)
|
|
{
|
|
if (unlikely(is_single_threaded(wq)))
|
|
cpu = singlethread_cpu;
|
|
return per_cpu_ptr(wq->cpu_wq, cpu);
|
|
}
|
|
|
|
/*
|
|
* Set the workqueue on which a work item is to be run
|
|
* - Must *only* be called if the pending flag is set
|
|
*/
|
|
static inline void set_wq_data(struct work_struct *work,
|
|
struct cpu_workqueue_struct *cwq)
|
|
{
|
|
unsigned long new;
|
|
|
|
BUG_ON(!work_pending(work));
|
|
|
|
new = (unsigned long) cwq | (1UL << WORK_STRUCT_PENDING);
|
|
new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work);
|
|
atomic_long_set(&work->data, new);
|
|
}
|
|
|
|
static inline
|
|
struct cpu_workqueue_struct *get_wq_data(struct work_struct *work)
|
|
{
|
|
return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK);
|
|
}
|
|
|
|
static void insert_work(struct cpu_workqueue_struct *cwq,
|
|
struct work_struct *work, int tail)
|
|
{
|
|
set_wq_data(work, cwq);
|
|
/*
|
|
* Ensure that we get the right work->data if we see the
|
|
* result of list_add() below, see try_to_grab_pending().
|
|
*/
|
|
smp_wmb();
|
|
if (tail)
|
|
list_add_tail(&work->entry, &cwq->worklist);
|
|
else
|
|
list_add(&work->entry, &cwq->worklist);
|
|
wake_up(&cwq->more_work);
|
|
}
|
|
|
|
static void __queue_work(struct cpu_workqueue_struct *cwq,
|
|
struct work_struct *work)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&cwq->lock, flags);
|
|
insert_work(cwq, work, 1);
|
|
spin_unlock_irqrestore(&cwq->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* queue_work - queue work on a workqueue
|
|
* @wq: workqueue to use
|
|
* @work: work to queue
|
|
*
|
|
* Returns 0 if @work was already on a queue, non-zero otherwise.
|
|
*
|
|
* We queue the work to the CPU on which it was submitted, but if the CPU dies
|
|
* it can be processed by another CPU.
|
|
*/
|
|
int queue_work(struct workqueue_struct *wq, struct work_struct *work)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
|
|
BUG_ON(!list_empty(&work->entry));
|
|
__queue_work(wq_per_cpu(wq, get_cpu()), work);
|
|
put_cpu();
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(queue_work);
|
|
|
|
/**
|
|
* queue_work_on - queue work on specific cpu
|
|
* @cpu: CPU number to execute work on
|
|
* @wq: workqueue to use
|
|
* @work: work to queue
|
|
*
|
|
* Returns 0 if @work was already on a queue, non-zero otherwise.
|
|
*
|
|
* We queue the work to a specific CPU, the caller must ensure it
|
|
* can't go away.
|
|
*/
|
|
int
|
|
queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
|
|
BUG_ON(!list_empty(&work->entry));
|
|
__queue_work(wq_per_cpu(wq, cpu), work);
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(queue_work_on);
|
|
|
|
static void delayed_work_timer_fn(unsigned long __data)
|
|
{
|
|
struct delayed_work *dwork = (struct delayed_work *)__data;
|
|
struct cpu_workqueue_struct *cwq = get_wq_data(&dwork->work);
|
|
struct workqueue_struct *wq = cwq->wq;
|
|
|
|
__queue_work(wq_per_cpu(wq, smp_processor_id()), &dwork->work);
|
|
}
|
|
|
|
/**
|
|
* queue_delayed_work - queue work on a workqueue after delay
|
|
* @wq: workqueue to use
|
|
* @dwork: delayable work to queue
|
|
* @delay: number of jiffies to wait before queueing
|
|
*
|
|
* Returns 0 if @work was already on a queue, non-zero otherwise.
|
|
*/
|
|
int queue_delayed_work(struct workqueue_struct *wq,
|
|
struct delayed_work *dwork, unsigned long delay)
|
|
{
|
|
if (delay == 0)
|
|
return queue_work(wq, &dwork->work);
|
|
|
|
return queue_delayed_work_on(-1, wq, dwork, delay);
|
|
}
|
|
EXPORT_SYMBOL_GPL(queue_delayed_work);
|
|
|
|
/**
|
|
* queue_delayed_work_on - queue work on specific CPU after delay
|
|
* @cpu: CPU number to execute work on
|
|
* @wq: workqueue to use
|
|
* @dwork: work to queue
|
|
* @delay: number of jiffies to wait before queueing
|
|
*
|
|
* Returns 0 if @work was already on a queue, non-zero otherwise.
|
|
*/
|
|
int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
|
|
struct delayed_work *dwork, unsigned long delay)
|
|
{
|
|
int ret = 0;
|
|
struct timer_list *timer = &dwork->timer;
|
|
struct work_struct *work = &dwork->work;
|
|
|
|
if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
|
|
BUG_ON(timer_pending(timer));
|
|
BUG_ON(!list_empty(&work->entry));
|
|
|
|
timer_stats_timer_set_start_info(&dwork->timer);
|
|
|
|
/* This stores cwq for the moment, for the timer_fn */
|
|
set_wq_data(work, wq_per_cpu(wq, raw_smp_processor_id()));
|
|
timer->expires = jiffies + delay;
|
|
timer->data = (unsigned long)dwork;
|
|
timer->function = delayed_work_timer_fn;
|
|
|
|
if (unlikely(cpu >= 0))
|
|
add_timer_on(timer, cpu);
|
|
else
|
|
add_timer(timer);
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(queue_delayed_work_on);
|
|
|
|
static void run_workqueue(struct cpu_workqueue_struct *cwq)
|
|
{
|
|
spin_lock_irq(&cwq->lock);
|
|
cwq->run_depth++;
|
|
if (cwq->run_depth > 3) {
|
|
/* morton gets to eat his hat */
|
|
printk("%s: recursion depth exceeded: %d\n",
|
|
__func__, cwq->run_depth);
|
|
dump_stack();
|
|
}
|
|
while (!list_empty(&cwq->worklist)) {
|
|
struct work_struct *work = list_entry(cwq->worklist.next,
|
|
struct work_struct, entry);
|
|
work_func_t f = work->func;
|
|
#ifdef CONFIG_LOCKDEP
|
|
/*
|
|
* It is permissible to free the struct work_struct
|
|
* from inside the function that is called from it,
|
|
* this we need to take into account for lockdep too.
|
|
* To avoid bogus "held lock freed" warnings as well
|
|
* as problems when looking into work->lockdep_map,
|
|
* make a copy and use that here.
|
|
*/
|
|
struct lockdep_map lockdep_map = work->lockdep_map;
|
|
#endif
|
|
|
|
cwq->current_work = work;
|
|
list_del_init(cwq->worklist.next);
|
|
spin_unlock_irq(&cwq->lock);
|
|
|
|
BUG_ON(get_wq_data(work) != cwq);
|
|
work_clear_pending(work);
|
|
lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
|
|
lock_acquire(&lockdep_map, 0, 0, 0, 2, _THIS_IP_);
|
|
f(work);
|
|
lock_release(&lockdep_map, 1, _THIS_IP_);
|
|
lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
|
|
|
|
if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
|
|
printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
|
|
"%s/0x%08x/%d\n",
|
|
current->comm, preempt_count(),
|
|
task_pid_nr(current));
|
|
printk(KERN_ERR " last function: ");
|
|
print_symbol("%s\n", (unsigned long)f);
|
|
debug_show_held_locks(current);
|
|
dump_stack();
|
|
}
|
|
|
|
spin_lock_irq(&cwq->lock);
|
|
cwq->current_work = NULL;
|
|
}
|
|
cwq->run_depth--;
|
|
spin_unlock_irq(&cwq->lock);
|
|
}
|
|
|
|
static int worker_thread(void *__cwq)
|
|
{
|
|
struct cpu_workqueue_struct *cwq = __cwq;
|
|
DEFINE_WAIT(wait);
|
|
|
|
if (cwq->wq->freezeable)
|
|
set_freezable();
|
|
|
|
set_user_nice(current, -5);
|
|
|
|
for (;;) {
|
|
prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
|
|
if (!freezing(current) &&
|
|
!kthread_should_stop() &&
|
|
list_empty(&cwq->worklist))
|
|
schedule();
|
|
finish_wait(&cwq->more_work, &wait);
|
|
|
|
try_to_freeze();
|
|
|
|
if (kthread_should_stop())
|
|
break;
|
|
|
|
run_workqueue(cwq);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct wq_barrier {
|
|
struct work_struct work;
|
|
struct completion done;
|
|
};
|
|
|
|
static void wq_barrier_func(struct work_struct *work)
|
|
{
|
|
struct wq_barrier *barr = container_of(work, struct wq_barrier, work);
|
|
complete(&barr->done);
|
|
}
|
|
|
|
static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
|
|
struct wq_barrier *barr, int tail)
|
|
{
|
|
INIT_WORK(&barr->work, wq_barrier_func);
|
|
__set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work));
|
|
|
|
init_completion(&barr->done);
|
|
|
|
insert_work(cwq, &barr->work, tail);
|
|
}
|
|
|
|
static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
|
|
{
|
|
int active;
|
|
|
|
if (cwq->thread == current) {
|
|
/*
|
|
* Probably keventd trying to flush its own queue. So simply run
|
|
* it by hand rather than deadlocking.
|
|
*/
|
|
run_workqueue(cwq);
|
|
active = 1;
|
|
} else {
|
|
struct wq_barrier barr;
|
|
|
|
active = 0;
|
|
spin_lock_irq(&cwq->lock);
|
|
if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) {
|
|
insert_wq_barrier(cwq, &barr, 1);
|
|
active = 1;
|
|
}
|
|
spin_unlock_irq(&cwq->lock);
|
|
|
|
if (active)
|
|
wait_for_completion(&barr.done);
|
|
}
|
|
|
|
return active;
|
|
}
|
|
|
|
/**
|
|
* flush_workqueue - ensure that any scheduled work has run to completion.
|
|
* @wq: workqueue to flush
|
|
*
|
|
* Forces execution of the workqueue and blocks until its completion.
|
|
* This is typically used in driver shutdown handlers.
|
|
*
|
|
* We sleep until all works which were queued on entry have been handled,
|
|
* but we are not livelocked by new incoming ones.
|
|
*
|
|
* This function used to run the workqueues itself. Now we just wait for the
|
|
* helper threads to do it.
|
|
*/
|
|
void flush_workqueue(struct workqueue_struct *wq)
|
|
{
|
|
const cpumask_t *cpu_map = wq_cpu_map(wq);
|
|
int cpu;
|
|
|
|
might_sleep();
|
|
lock_acquire(&wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
|
|
lock_release(&wq->lockdep_map, 1, _THIS_IP_);
|
|
for_each_cpu_mask_nr(cpu, *cpu_map)
|
|
flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu));
|
|
}
|
|
EXPORT_SYMBOL_GPL(flush_workqueue);
|
|
|
|
/*
|
|
* Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit,
|
|
* so this work can't be re-armed in any way.
|
|
*/
|
|
static int try_to_grab_pending(struct work_struct *work)
|
|
{
|
|
struct cpu_workqueue_struct *cwq;
|
|
int ret = -1;
|
|
|
|
if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work)))
|
|
return 0;
|
|
|
|
/*
|
|
* The queueing is in progress, or it is already queued. Try to
|
|
* steal it from ->worklist without clearing WORK_STRUCT_PENDING.
|
|
*/
|
|
|
|
cwq = get_wq_data(work);
|
|
if (!cwq)
|
|
return ret;
|
|
|
|
spin_lock_irq(&cwq->lock);
|
|
if (!list_empty(&work->entry)) {
|
|
/*
|
|
* This work is queued, but perhaps we locked the wrong cwq.
|
|
* In that case we must see the new value after rmb(), see
|
|
* insert_work()->wmb().
|
|
*/
|
|
smp_rmb();
|
|
if (cwq == get_wq_data(work)) {
|
|
list_del_init(&work->entry);
|
|
ret = 1;
|
|
}
|
|
}
|
|
spin_unlock_irq(&cwq->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq,
|
|
struct work_struct *work)
|
|
{
|
|
struct wq_barrier barr;
|
|
int running = 0;
|
|
|
|
spin_lock_irq(&cwq->lock);
|
|
if (unlikely(cwq->current_work == work)) {
|
|
insert_wq_barrier(cwq, &barr, 0);
|
|
running = 1;
|
|
}
|
|
spin_unlock_irq(&cwq->lock);
|
|
|
|
if (unlikely(running))
|
|
wait_for_completion(&barr.done);
|
|
}
|
|
|
|
static void wait_on_work(struct work_struct *work)
|
|
{
|
|
struct cpu_workqueue_struct *cwq;
|
|
struct workqueue_struct *wq;
|
|
const cpumask_t *cpu_map;
|
|
int cpu;
|
|
|
|
might_sleep();
|
|
|
|
lock_acquire(&work->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
|
|
lock_release(&work->lockdep_map, 1, _THIS_IP_);
|
|
|
|
cwq = get_wq_data(work);
|
|
if (!cwq)
|
|
return;
|
|
|
|
wq = cwq->wq;
|
|
cpu_map = wq_cpu_map(wq);
|
|
|
|
for_each_cpu_mask_nr(cpu, *cpu_map)
|
|
wait_on_cpu_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
|
|
}
|
|
|
|
static int __cancel_work_timer(struct work_struct *work,
|
|
struct timer_list* timer)
|
|
{
|
|
int ret;
|
|
|
|
do {
|
|
ret = (timer && likely(del_timer(timer)));
|
|
if (!ret)
|
|
ret = try_to_grab_pending(work);
|
|
wait_on_work(work);
|
|
} while (unlikely(ret < 0));
|
|
|
|
work_clear_pending(work);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* cancel_work_sync - block until a work_struct's callback has terminated
|
|
* @work: the work which is to be flushed
|
|
*
|
|
* Returns true if @work was pending.
|
|
*
|
|
* cancel_work_sync() will cancel the work if it is queued. If the work's
|
|
* callback appears to be running, cancel_work_sync() will block until it
|
|
* has completed.
|
|
*
|
|
* It is possible to use this function if the work re-queues itself. It can
|
|
* cancel the work even if it migrates to another workqueue, however in that
|
|
* case it only guarantees that work->func() has completed on the last queued
|
|
* workqueue.
|
|
*
|
|
* cancel_work_sync(&delayed_work->work) should be used only if ->timer is not
|
|
* pending, otherwise it goes into a busy-wait loop until the timer expires.
|
|
*
|
|
* The caller must ensure that workqueue_struct on which this work was last
|
|
* queued can't be destroyed before this function returns.
|
|
*/
|
|
int cancel_work_sync(struct work_struct *work)
|
|
{
|
|
return __cancel_work_timer(work, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cancel_work_sync);
|
|
|
|
/**
|
|
* cancel_delayed_work_sync - reliably kill off a delayed work.
|
|
* @dwork: the delayed work struct
|
|
*
|
|
* Returns true if @dwork was pending.
|
|
*
|
|
* It is possible to use this function if @dwork rearms itself via queue_work()
|
|
* or queue_delayed_work(). See also the comment for cancel_work_sync().
|
|
*/
|
|
int cancel_delayed_work_sync(struct delayed_work *dwork)
|
|
{
|
|
return __cancel_work_timer(&dwork->work, &dwork->timer);
|
|
}
|
|
EXPORT_SYMBOL(cancel_delayed_work_sync);
|
|
|
|
static struct workqueue_struct *keventd_wq __read_mostly;
|
|
|
|
/**
|
|
* schedule_work - put work task in global workqueue
|
|
* @work: job to be done
|
|
*
|
|
* This puts a job in the kernel-global workqueue.
|
|
*/
|
|
int schedule_work(struct work_struct *work)
|
|
{
|
|
return queue_work(keventd_wq, work);
|
|
}
|
|
EXPORT_SYMBOL(schedule_work);
|
|
|
|
/*
|
|
* schedule_work_on - put work task on a specific cpu
|
|
* @cpu: cpu to put the work task on
|
|
* @work: job to be done
|
|
*
|
|
* This puts a job on a specific cpu
|
|
*/
|
|
int schedule_work_on(int cpu, struct work_struct *work)
|
|
{
|
|
return queue_work_on(cpu, keventd_wq, work);
|
|
}
|
|
EXPORT_SYMBOL(schedule_work_on);
|
|
|
|
/**
|
|
* schedule_delayed_work - put work task in global workqueue after delay
|
|
* @dwork: job to be done
|
|
* @delay: number of jiffies to wait or 0 for immediate execution
|
|
*
|
|
* After waiting for a given time this puts a job in the kernel-global
|
|
* workqueue.
|
|
*/
|
|
int schedule_delayed_work(struct delayed_work *dwork,
|
|
unsigned long delay)
|
|
{
|
|
return queue_delayed_work(keventd_wq, dwork, delay);
|
|
}
|
|
EXPORT_SYMBOL(schedule_delayed_work);
|
|
|
|
/**
|
|
* schedule_delayed_work_on - queue work in global workqueue on CPU after delay
|
|
* @cpu: cpu to use
|
|
* @dwork: job to be done
|
|
* @delay: number of jiffies to wait
|
|
*
|
|
* After waiting for a given time this puts a job in the kernel-global
|
|
* workqueue on the specified CPU.
|
|
*/
|
|
int schedule_delayed_work_on(int cpu,
|
|
struct delayed_work *dwork, unsigned long delay)
|
|
{
|
|
return queue_delayed_work_on(cpu, keventd_wq, dwork, delay);
|
|
}
|
|
EXPORT_SYMBOL(schedule_delayed_work_on);
|
|
|
|
/**
|
|
* schedule_on_each_cpu - call a function on each online CPU from keventd
|
|
* @func: the function to call
|
|
*
|
|
* Returns zero on success.
|
|
* Returns -ve errno on failure.
|
|
*
|
|
* schedule_on_each_cpu() is very slow.
|
|
*/
|
|
int schedule_on_each_cpu(work_func_t func)
|
|
{
|
|
int cpu;
|
|
struct work_struct *works;
|
|
|
|
works = alloc_percpu(struct work_struct);
|
|
if (!works)
|
|
return -ENOMEM;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu) {
|
|
struct work_struct *work = per_cpu_ptr(works, cpu);
|
|
|
|
INIT_WORK(work, func);
|
|
set_bit(WORK_STRUCT_PENDING, work_data_bits(work));
|
|
__queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work);
|
|
}
|
|
flush_workqueue(keventd_wq);
|
|
put_online_cpus();
|
|
free_percpu(works);
|
|
return 0;
|
|
}
|
|
|
|
void flush_scheduled_work(void)
|
|
{
|
|
flush_workqueue(keventd_wq);
|
|
}
|
|
EXPORT_SYMBOL(flush_scheduled_work);
|
|
|
|
/**
|
|
* execute_in_process_context - reliably execute the routine with user context
|
|
* @fn: the function to execute
|
|
* @ew: guaranteed storage for the execute work structure (must
|
|
* be available when the work executes)
|
|
*
|
|
* Executes the function immediately if process context is available,
|
|
* otherwise schedules the function for delayed execution.
|
|
*
|
|
* Returns: 0 - function was executed
|
|
* 1 - function was scheduled for execution
|
|
*/
|
|
int execute_in_process_context(work_func_t fn, struct execute_work *ew)
|
|
{
|
|
if (!in_interrupt()) {
|
|
fn(&ew->work);
|
|
return 0;
|
|
}
|
|
|
|
INIT_WORK(&ew->work, fn);
|
|
schedule_work(&ew->work);
|
|
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(execute_in_process_context);
|
|
|
|
int keventd_up(void)
|
|
{
|
|
return keventd_wq != NULL;
|
|
}
|
|
|
|
int current_is_keventd(void)
|
|
{
|
|
struct cpu_workqueue_struct *cwq;
|
|
int cpu = raw_smp_processor_id(); /* preempt-safe: keventd is per-cpu */
|
|
int ret = 0;
|
|
|
|
BUG_ON(!keventd_wq);
|
|
|
|
cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu);
|
|
if (current == cwq->thread)
|
|
ret = 1;
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
static struct cpu_workqueue_struct *
|
|
init_cpu_workqueue(struct workqueue_struct *wq, int cpu)
|
|
{
|
|
struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
|
|
|
|
cwq->wq = wq;
|
|
spin_lock_init(&cwq->lock);
|
|
INIT_LIST_HEAD(&cwq->worklist);
|
|
init_waitqueue_head(&cwq->more_work);
|
|
|
|
return cwq;
|
|
}
|
|
|
|
static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
|
|
{
|
|
struct workqueue_struct *wq = cwq->wq;
|
|
const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d";
|
|
struct task_struct *p;
|
|
|
|
p = kthread_create(worker_thread, cwq, fmt, wq->name, cpu);
|
|
/*
|
|
* Nobody can add the work_struct to this cwq,
|
|
* if (caller is __create_workqueue)
|
|
* nobody should see this wq
|
|
* else // caller is CPU_UP_PREPARE
|
|
* cpu is not on cpu_online_map
|
|
* so we can abort safely.
|
|
*/
|
|
if (IS_ERR(p))
|
|
return PTR_ERR(p);
|
|
|
|
cwq->thread = p;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
|
|
{
|
|
struct task_struct *p = cwq->thread;
|
|
|
|
if (p != NULL) {
|
|
if (cpu >= 0)
|
|
kthread_bind(p, cpu);
|
|
wake_up_process(p);
|
|
}
|
|
}
|
|
|
|
struct workqueue_struct *__create_workqueue_key(const char *name,
|
|
int singlethread,
|
|
int freezeable,
|
|
struct lock_class_key *key,
|
|
const char *lock_name)
|
|
{
|
|
struct workqueue_struct *wq;
|
|
struct cpu_workqueue_struct *cwq;
|
|
int err = 0, cpu;
|
|
|
|
wq = kzalloc(sizeof(*wq), GFP_KERNEL);
|
|
if (!wq)
|
|
return NULL;
|
|
|
|
wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct);
|
|
if (!wq->cpu_wq) {
|
|
kfree(wq);
|
|
return NULL;
|
|
}
|
|
|
|
wq->name = name;
|
|
lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
|
|
wq->singlethread = singlethread;
|
|
wq->freezeable = freezeable;
|
|
INIT_LIST_HEAD(&wq->list);
|
|
|
|
if (singlethread) {
|
|
cwq = init_cpu_workqueue(wq, singlethread_cpu);
|
|
err = create_workqueue_thread(cwq, singlethread_cpu);
|
|
start_workqueue_thread(cwq, -1);
|
|
} else {
|
|
get_online_cpus();
|
|
spin_lock(&workqueue_lock);
|
|
list_add(&wq->list, &workqueues);
|
|
spin_unlock(&workqueue_lock);
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
cwq = init_cpu_workqueue(wq, cpu);
|
|
if (err || !cpu_online(cpu))
|
|
continue;
|
|
err = create_workqueue_thread(cwq, cpu);
|
|
start_workqueue_thread(cwq, cpu);
|
|
}
|
|
put_online_cpus();
|
|
}
|
|
|
|
if (err) {
|
|
destroy_workqueue(wq);
|
|
wq = NULL;
|
|
}
|
|
return wq;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__create_workqueue_key);
|
|
|
|
static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq)
|
|
{
|
|
/*
|
|
* Our caller is either destroy_workqueue() or CPU_DEAD,
|
|
* get_online_cpus() protects cwq->thread.
|
|
*/
|
|
if (cwq->thread == NULL)
|
|
return;
|
|
|
|
lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
|
|
lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
|
|
|
|
flush_cpu_workqueue(cwq);
|
|
/*
|
|
* If the caller is CPU_DEAD and cwq->worklist was not empty,
|
|
* a concurrent flush_workqueue() can insert a barrier after us.
|
|
* However, in that case run_workqueue() won't return and check
|
|
* kthread_should_stop() until it flushes all work_struct's.
|
|
* When ->worklist becomes empty it is safe to exit because no
|
|
* more work_structs can be queued on this cwq: flush_workqueue
|
|
* checks list_empty(), and a "normal" queue_work() can't use
|
|
* a dead CPU.
|
|
*/
|
|
kthread_stop(cwq->thread);
|
|
cwq->thread = NULL;
|
|
}
|
|
|
|
/**
|
|
* destroy_workqueue - safely terminate a workqueue
|
|
* @wq: target workqueue
|
|
*
|
|
* Safely destroy a workqueue. All work currently pending will be done first.
|
|
*/
|
|
void destroy_workqueue(struct workqueue_struct *wq)
|
|
{
|
|
const cpumask_t *cpu_map = wq_cpu_map(wq);
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
spin_lock(&workqueue_lock);
|
|
list_del(&wq->list);
|
|
spin_unlock(&workqueue_lock);
|
|
|
|
for_each_cpu_mask_nr(cpu, *cpu_map)
|
|
cleanup_workqueue_thread(per_cpu_ptr(wq->cpu_wq, cpu));
|
|
put_online_cpus();
|
|
|
|
free_percpu(wq->cpu_wq);
|
|
kfree(wq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(destroy_workqueue);
|
|
|
|
static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
unsigned int cpu = (unsigned long)hcpu;
|
|
struct cpu_workqueue_struct *cwq;
|
|
struct workqueue_struct *wq;
|
|
|
|
action &= ~CPU_TASKS_FROZEN;
|
|
|
|
switch (action) {
|
|
case CPU_UP_PREPARE:
|
|
cpu_set(cpu, cpu_populated_map);
|
|
}
|
|
|
|
list_for_each_entry(wq, &workqueues, list) {
|
|
cwq = per_cpu_ptr(wq->cpu_wq, cpu);
|
|
|
|
switch (action) {
|
|
case CPU_UP_PREPARE:
|
|
if (!create_workqueue_thread(cwq, cpu))
|
|
break;
|
|
printk(KERN_ERR "workqueue [%s] for %i failed\n",
|
|
wq->name, cpu);
|
|
return NOTIFY_BAD;
|
|
|
|
case CPU_ONLINE:
|
|
start_workqueue_thread(cwq, cpu);
|
|
break;
|
|
|
|
case CPU_UP_CANCELED:
|
|
start_workqueue_thread(cwq, -1);
|
|
case CPU_DEAD:
|
|
cleanup_workqueue_thread(cwq);
|
|
break;
|
|
}
|
|
}
|
|
|
|
switch (action) {
|
|
case CPU_UP_CANCELED:
|
|
case CPU_DEAD:
|
|
cpu_clear(cpu, cpu_populated_map);
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
void __init init_workqueues(void)
|
|
{
|
|
cpu_populated_map = cpu_online_map;
|
|
singlethread_cpu = first_cpu(cpu_possible_map);
|
|
cpu_singlethread_map = cpumask_of_cpu(singlethread_cpu);
|
|
hotcpu_notifier(workqueue_cpu_callback, 0);
|
|
keventd_wq = create_workqueue("events");
|
|
BUG_ON(!keventd_wq);
|
|
}
|