/*
* 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
* 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>
#define CREATE_TRACE_POINTS
#include <trace/events/workqueue.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;
} ____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 */
int rt;
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
};
#ifdef CONFIG_LOCKDEP
/**
* in_workqueue_context() - in context of specified workqueue?
* @wq: the workqueue of interest
*
* Checks lockdep state to see if the current task is executing from
* within a workqueue item. This function exists only if lockdep is
* enabled.
*/
int in_workqueue_context(struct workqueue_struct *wq)
{
return lock_is_held(&wq->lockdep_map);
}
#endif
#ifdef CONFIG_DEBUG_OBJECTS_WORK
static struct debug_obj_descr work_debug_descr;
/*
* fixup_init is called when:
* - an active object is initialized
*/
static int work_fixup_init(void *addr, enum debug_obj_state state)
{
struct work_struct *work = addr;
switch (state) {
case ODEBUG_STATE_ACTIVE:
cancel_work_sync(work);
debug_object_init(work, &work_debug_descr);
return 1;
default:
return 0;
}
}
/*
* fixup_activate is called when:
* - an active object is activated
* - an unknown object is activated (might be a statically initialized object)
*/
static int work_fixup_activate(void *addr, enum debug_obj_state state)
{
struct work_struct *work = addr;
switch (state) {
case ODEBUG_STATE_NOTAVAILABLE:
/*
* This is not really a fixup. The work struct was
* statically initialized. We just make sure that it
* is tracked in the object tracker.
*/
if (test_bit(WORK_STRUCT_STATIC, work_data_bits(work))) {
debug_object_init(work, &work_debug_descr);
debug_object_activate(work, &work_debug_descr);
return 0;
}
WARN_ON_ONCE(1);
return 0;
case ODEBUG_STATE_ACTIVE:
WARN_ON(1);
default:
return 0;
}
}
/*
* fixup_free is called when:
* - an active object is freed
*/
static int work_fixup_free(void *addr, enum debug_obj_state state)
{
struct work_struct *work = addr;
switch (state) {
case ODEBUG_STATE_ACTIVE: