805 lines
27 KiB
C
805 lines
27 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* workqueue.h --- work queue handling for Linux.
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*/
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#ifndef _LINUX_WORKQUEUE_H
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#define _LINUX_WORKQUEUE_H
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#include <linux/timer.h>
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#include <linux/linkage.h>
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#include <linux/bitops.h>
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#include <linux/lockdep.h>
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#include <linux/threads.h>
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#include <linux/atomic.h>
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#include <linux/cpumask.h>
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#include <linux/rcupdate.h>
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#include <linux/workqueue_types.h>
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/*
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* The first word is the work queue pointer and the flags rolled into
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* one
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*/
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#define work_data_bits(work) ((unsigned long *)(&(work)->data))
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enum work_bits {
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WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
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WORK_STRUCT_INACTIVE_BIT, /* work item is inactive */
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WORK_STRUCT_PWQ_BIT, /* data points to pwq */
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WORK_STRUCT_LINKED_BIT, /* next work is linked to this one */
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#ifdef CONFIG_DEBUG_OBJECTS_WORK
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WORK_STRUCT_STATIC_BIT, /* static initializer (debugobjects) */
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#endif
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WORK_STRUCT_FLAG_BITS,
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/* color for workqueue flushing */
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WORK_STRUCT_COLOR_SHIFT = WORK_STRUCT_FLAG_BITS,
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WORK_STRUCT_COLOR_BITS = 4,
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/*
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* When WORK_STRUCT_PWQ is set, reserve 8 bits off of pwq pointer w/
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* debugobjects turned off. This makes pwqs aligned to 256 bytes (512
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* bytes w/ DEBUG_OBJECTS_WORK) and allows 16 workqueue flush colors.
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*
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* MSB
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* [ pwq pointer ] [ flush color ] [ STRUCT flags ]
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* 4 bits 4 or 5 bits
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*/
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WORK_STRUCT_PWQ_SHIFT = WORK_STRUCT_COLOR_SHIFT + WORK_STRUCT_COLOR_BITS,
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/*
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* data contains off-queue information when !WORK_STRUCT_PWQ.
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*
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* MSB
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* [ pool ID ] [ OFFQ flags ] [ STRUCT flags ]
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* 1 bit 4 or 5 bits
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*/
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WORK_OFFQ_FLAG_SHIFT = WORK_STRUCT_FLAG_BITS,
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WORK_OFFQ_CANCELING_BIT = WORK_OFFQ_FLAG_SHIFT,
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WORK_OFFQ_FLAG_END,
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WORK_OFFQ_FLAG_BITS = WORK_OFFQ_FLAG_END - WORK_OFFQ_FLAG_SHIFT,
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/*
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* When a work item is off queue, the high bits encode off-queue flags
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* and the last pool it was on. Cap pool ID to 31 bits and use the
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* highest number to indicate that no pool is associated.
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*/
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WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_SHIFT + WORK_OFFQ_FLAG_BITS,
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WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
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WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
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};
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enum work_flags {
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WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
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WORK_STRUCT_INACTIVE = 1 << WORK_STRUCT_INACTIVE_BIT,
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WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT,
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WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
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#ifdef CONFIG_DEBUG_OBJECTS_WORK
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WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
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#else
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WORK_STRUCT_STATIC = 0,
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#endif
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};
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enum wq_misc_consts {
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WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS),
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/* not bound to any CPU, prefer the local CPU */
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WORK_CPU_UNBOUND = NR_CPUS,
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/* bit mask for work_busy() return values */
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WORK_BUSY_PENDING = 1 << 0,
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WORK_BUSY_RUNNING = 1 << 1,
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/* maximum string length for set_worker_desc() */
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WORKER_DESC_LEN = 24,
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};
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/* Convenience constants - of type 'unsigned long', not 'enum'! */
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#define WORK_OFFQ_CANCELING (1ul << WORK_OFFQ_CANCELING_BIT)
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#define WORK_OFFQ_POOL_NONE ((1ul << WORK_OFFQ_POOL_BITS) - 1)
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#define WORK_STRUCT_NO_POOL (WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT)
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#define WORK_STRUCT_PWQ_MASK (~((1ul << WORK_STRUCT_PWQ_SHIFT) - 1))
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#define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL)
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#define WORK_DATA_STATIC_INIT() \
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ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
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struct delayed_work {
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struct work_struct work;
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struct timer_list timer;
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/* target workqueue and CPU ->timer uses to queue ->work */
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struct workqueue_struct *wq;
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int cpu;
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};
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struct rcu_work {
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struct work_struct work;
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struct rcu_head rcu;
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/* target workqueue ->rcu uses to queue ->work */
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struct workqueue_struct *wq;
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};
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enum wq_affn_scope {
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WQ_AFFN_DFL, /* use system default */
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WQ_AFFN_CPU, /* one pod per CPU */
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WQ_AFFN_SMT, /* one pod poer SMT */
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WQ_AFFN_CACHE, /* one pod per LLC */
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WQ_AFFN_NUMA, /* one pod per NUMA node */
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WQ_AFFN_SYSTEM, /* one pod across the whole system */
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WQ_AFFN_NR_TYPES,
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};
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/**
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* struct workqueue_attrs - A struct for workqueue attributes.
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*
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* This can be used to change attributes of an unbound workqueue.
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*/
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struct workqueue_attrs {
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/**
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* @nice: nice level
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*/
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int nice;
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/**
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* @cpumask: allowed CPUs
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*
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* Work items in this workqueue are affine to these CPUs and not allowed
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* to execute on other CPUs. A pool serving a workqueue must have the
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* same @cpumask.
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*/
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cpumask_var_t cpumask;
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/**
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* @__pod_cpumask: internal attribute used to create per-pod pools
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*
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* Internal use only.
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*
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* Per-pod unbound worker pools are used to improve locality. Always a
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* subset of ->cpumask. A workqueue can be associated with multiple
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* worker pools with disjoint @__pod_cpumask's. Whether the enforcement
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* of a pool's @__pod_cpumask is strict depends on @affn_strict.
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*/
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cpumask_var_t __pod_cpumask;
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/**
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* @affn_strict: affinity scope is strict
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*
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* If clear, workqueue will make a best-effort attempt at starting the
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* worker inside @__pod_cpumask but the scheduler is free to migrate it
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* outside.
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*
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* If set, workers are only allowed to run inside @__pod_cpumask.
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*/
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bool affn_strict;
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/*
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* Below fields aren't properties of a worker_pool. They only modify how
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* :c:func:`apply_workqueue_attrs` select pools and thus don't
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* participate in pool hash calculations or equality comparisons.
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*/
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/**
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* @affn_scope: unbound CPU affinity scope
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*
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* CPU pods are used to improve execution locality of unbound work
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* items. There are multiple pod types, one for each wq_affn_scope, and
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* every CPU in the system belongs to one pod in every pod type. CPUs
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* that belong to the same pod share the worker pool. For example,
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* selecting %WQ_AFFN_NUMA makes the workqueue use a separate worker
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* pool for each NUMA node.
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*/
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enum wq_affn_scope affn_scope;
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/**
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* @ordered: work items must be executed one by one in queueing order
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*/
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bool ordered;
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};
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static inline struct delayed_work *to_delayed_work(struct work_struct *work)
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{
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return container_of(work, struct delayed_work, work);
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}
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static inline struct rcu_work *to_rcu_work(struct work_struct *work)
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{
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return container_of(work, struct rcu_work, work);
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}
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struct execute_work {
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struct work_struct work;
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};
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#ifdef CONFIG_LOCKDEP
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/*
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* NB: because we have to copy the lockdep_map, setting _key
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* here is required, otherwise it could get initialised to the
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* copy of the lockdep_map!
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*/
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#define __WORK_INIT_LOCKDEP_MAP(n, k) \
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.lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
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#else
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#define __WORK_INIT_LOCKDEP_MAP(n, k)
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#endif
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#define __WORK_INITIALIZER(n, f) { \
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.data = WORK_DATA_STATIC_INIT(), \
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.entry = { &(n).entry, &(n).entry }, \
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.func = (f), \
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__WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
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}
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#define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
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.work = __WORK_INITIALIZER((n).work, (f)), \
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.timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\
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(tflags) | TIMER_IRQSAFE), \
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}
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#define DECLARE_WORK(n, f) \
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struct work_struct n = __WORK_INITIALIZER(n, f)
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#define DECLARE_DELAYED_WORK(n, f) \
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struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
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#define DECLARE_DEFERRABLE_WORK(n, f) \
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struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
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#ifdef CONFIG_DEBUG_OBJECTS_WORK
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extern void __init_work(struct work_struct *work, int onstack);
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extern void destroy_work_on_stack(struct work_struct *work);
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extern void destroy_delayed_work_on_stack(struct delayed_work *work);
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static inline unsigned int work_static(struct work_struct *work)
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{
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return *work_data_bits(work) & WORK_STRUCT_STATIC;
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}
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#else
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static inline void __init_work(struct work_struct *work, int onstack) { }
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static inline void destroy_work_on_stack(struct work_struct *work) { }
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static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
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static inline unsigned int work_static(struct work_struct *work) { return 0; }
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#endif
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/*
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* initialize all of a work item in one go
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*
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* NOTE! No point in using "atomic_long_set()": using a direct
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* assignment of the work data initializer allows the compiler
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* to generate better code.
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*/
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#ifdef CONFIG_LOCKDEP
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#define __INIT_WORK_KEY(_work, _func, _onstack, _key) \
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do { \
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__init_work((_work), _onstack); \
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(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
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lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, (_key), 0); \
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INIT_LIST_HEAD(&(_work)->entry); \
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(_work)->func = (_func); \
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} while (0)
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#else
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#define __INIT_WORK_KEY(_work, _func, _onstack, _key) \
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do { \
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__init_work((_work), _onstack); \
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(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
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INIT_LIST_HEAD(&(_work)->entry); \
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(_work)->func = (_func); \
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} while (0)
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#endif
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#define __INIT_WORK(_work, _func, _onstack) \
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do { \
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static __maybe_unused struct lock_class_key __key; \
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\
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__INIT_WORK_KEY(_work, _func, _onstack, &__key); \
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} while (0)
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#define INIT_WORK(_work, _func) \
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__INIT_WORK((_work), (_func), 0)
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#define INIT_WORK_ONSTACK(_work, _func) \
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__INIT_WORK((_work), (_func), 1)
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#define INIT_WORK_ONSTACK_KEY(_work, _func, _key) \
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__INIT_WORK_KEY((_work), (_func), 1, _key)
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#define __INIT_DELAYED_WORK(_work, _func, _tflags) \
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do { \
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INIT_WORK(&(_work)->work, (_func)); \
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__init_timer(&(_work)->timer, \
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delayed_work_timer_fn, \
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(_tflags) | TIMER_IRQSAFE); \
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} while (0)
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#define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
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do { \
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INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
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__init_timer_on_stack(&(_work)->timer, \
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delayed_work_timer_fn, \
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(_tflags) | TIMER_IRQSAFE); \
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} while (0)
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#define INIT_DELAYED_WORK(_work, _func) \
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__INIT_DELAYED_WORK(_work, _func, 0)
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#define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
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__INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
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#define INIT_DEFERRABLE_WORK(_work, _func) \
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__INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
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#define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
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__INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
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#define INIT_RCU_WORK(_work, _func) \
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INIT_WORK(&(_work)->work, (_func))
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#define INIT_RCU_WORK_ONSTACK(_work, _func) \
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INIT_WORK_ONSTACK(&(_work)->work, (_func))
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/**
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* work_pending - Find out whether a work item is currently pending
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* @work: The work item in question
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*/
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#define work_pending(work) \
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test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
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/**
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* delayed_work_pending - Find out whether a delayable work item is currently
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* pending
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* @w: The work item in question
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*/
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#define delayed_work_pending(w) \
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work_pending(&(w)->work)
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/*
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* Workqueue flags and constants. For details, please refer to
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* Documentation/core-api/workqueue.rst.
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*/
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enum wq_flags {
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WQ_BH = 1 << 0, /* execute in bottom half (softirq) context */
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WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
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WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
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WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
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WQ_HIGHPRI = 1 << 4, /* high priority */
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WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
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WQ_SYSFS = 1 << 6, /* visible in sysfs, see workqueue_sysfs_register() */
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/*
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* Per-cpu workqueues are generally preferred because they tend to
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* show better performance thanks to cache locality. Per-cpu
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* workqueues exclude the scheduler from choosing the CPU to
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* execute the worker threads, which has an unfortunate side effect
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* of increasing power consumption.
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*
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* The scheduler considers a CPU idle if it doesn't have any task
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* to execute and tries to keep idle cores idle to conserve power;
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* however, for example, a per-cpu work item scheduled from an
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* interrupt handler on an idle CPU will force the scheduler to
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* execute the work item on that CPU breaking the idleness, which in
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* turn may lead to more scheduling choices which are sub-optimal
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* in terms of power consumption.
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*
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* Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
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* but become unbound if workqueue.power_efficient kernel param is
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* specified. Per-cpu workqueues which are identified to
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* contribute significantly to power-consumption are identified and
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* marked with this flag and enabling the power_efficient mode
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* leads to noticeable power saving at the cost of small
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* performance disadvantage.
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*
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* http://thread.gmane.org/gmane.linux.kernel/1480396
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*/
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WQ_POWER_EFFICIENT = 1 << 7,
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__WQ_DESTROYING = 1 << 15, /* internal: workqueue is destroying */
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__WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
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__WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
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__WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
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/* BH wq only allows the following flags */
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__WQ_BH_ALLOWS = WQ_BH | WQ_HIGHPRI,
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};
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enum wq_consts {
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WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
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WQ_UNBOUND_MAX_ACTIVE = WQ_MAX_ACTIVE,
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WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
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/*
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* Per-node default cap on min_active. Unless explicitly set, min_active
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* is set to min(max_active, WQ_DFL_MIN_ACTIVE). For more details, see
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* workqueue_struct->min_active definition.
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*/
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WQ_DFL_MIN_ACTIVE = 8,
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};
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/*
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* System-wide workqueues which are always present.
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*
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* system_wq is the one used by schedule[_delayed]_work[_on]().
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* Multi-CPU multi-threaded. There are users which expect relatively
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* short queue flush time. Don't queue works which can run for too
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* long.
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*
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* system_highpri_wq is similar to system_wq but for work items which
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* require WQ_HIGHPRI.
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*
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* system_long_wq is similar to system_wq but may host long running
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* works. Queue flushing might take relatively long.
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*
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* system_unbound_wq is unbound workqueue. Workers are not bound to
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* any specific CPU, not concurrency managed, and all queued works are
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* executed immediately as long as max_active limit is not reached and
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* resources are available.
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*
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* system_freezable_wq is equivalent to system_wq except that it's
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* freezable.
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*
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* *_power_efficient_wq are inclined towards saving power and converted
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* into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
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* they are same as their non-power-efficient counterparts - e.g.
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* system_power_efficient_wq is identical to system_wq if
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* 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
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*
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* system_bh[_highpri]_wq are convenience interface to softirq. BH work items
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* are executed in the queueing CPU's BH context in the queueing order.
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*/
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extern struct workqueue_struct *system_wq;
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extern struct workqueue_struct *system_highpri_wq;
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extern struct workqueue_struct *system_long_wq;
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extern struct workqueue_struct *system_unbound_wq;
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extern struct workqueue_struct *system_freezable_wq;
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extern struct workqueue_struct *system_power_efficient_wq;
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extern struct workqueue_struct *system_freezable_power_efficient_wq;
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extern struct workqueue_struct *system_bh_wq;
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extern struct workqueue_struct *system_bh_highpri_wq;
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void workqueue_softirq_action(bool highpri);
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void workqueue_softirq_dead(unsigned int cpu);
|
|
|
|
/**
|
|
* alloc_workqueue - allocate a workqueue
|
|
* @fmt: printf format for the name of the workqueue
|
|
* @flags: WQ_* flags
|
|
* @max_active: max in-flight work items, 0 for default
|
|
* remaining args: args for @fmt
|
|
*
|
|
* For a per-cpu workqueue, @max_active limits the number of in-flight work
|
|
* items for each CPU. e.g. @max_active of 1 indicates that each CPU can be
|
|
* executing at most one work item for the workqueue.
|
|
*
|
|
* For unbound workqueues, @max_active limits the number of in-flight work items
|
|
* for the whole system. e.g. @max_active of 16 indicates that that there can be
|
|
* at most 16 work items executing for the workqueue in the whole system.
|
|
*
|
|
* As sharing the same active counter for an unbound workqueue across multiple
|
|
* NUMA nodes can be expensive, @max_active is distributed to each NUMA node
|
|
* according to the proportion of the number of online CPUs and enforced
|
|
* independently.
|
|
*
|
|
* Depending on online CPU distribution, a node may end up with per-node
|
|
* max_active which is significantly lower than @max_active, which can lead to
|
|
* deadlocks if the per-node concurrency limit is lower than the maximum number
|
|
* of interdependent work items for the workqueue.
|
|
*
|
|
* To guarantee forward progress regardless of online CPU distribution, the
|
|
* concurrency limit on every node is guaranteed to be equal to or greater than
|
|
* min_active which is set to min(@max_active, %WQ_DFL_MIN_ACTIVE). This means
|
|
* that the sum of per-node max_active's may be larger than @max_active.
|
|
*
|
|
* For detailed information on %WQ_* flags, please refer to
|
|
* Documentation/core-api/workqueue.rst.
|
|
*
|
|
* RETURNS:
|
|
* Pointer to the allocated workqueue on success, %NULL on failure.
|
|
*/
|
|
__printf(1, 4) struct workqueue_struct *
|
|
alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);
|
|
|
|
/**
|
|
* alloc_ordered_workqueue - allocate an ordered workqueue
|
|
* @fmt: printf format for the name of the workqueue
|
|
* @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
|
|
* @args: args for @fmt
|
|
*
|
|
* Allocate an ordered workqueue. An ordered workqueue executes at
|
|
* most one work item at any given time in the queued order. They are
|
|
* implemented as unbound workqueues with @max_active of one.
|
|
*
|
|
* RETURNS:
|
|
* Pointer to the allocated workqueue on success, %NULL on failure.
|
|
*/
|
|
#define alloc_ordered_workqueue(fmt, flags, args...) \
|
|
alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)
|
|
|
|
#define create_workqueue(name) \
|
|
alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
|
|
#define create_freezable_workqueue(name) \
|
|
alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
|
|
WQ_MEM_RECLAIM, 1, (name))
|
|
#define create_singlethread_workqueue(name) \
|
|
alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
|
|
|
|
#define from_work(var, callback_work, work_fieldname) \
|
|
container_of(callback_work, typeof(*var), work_fieldname)
|
|
|
|
extern void destroy_workqueue(struct workqueue_struct *wq);
|
|
|
|
struct workqueue_attrs *alloc_workqueue_attrs(void);
|
|
void free_workqueue_attrs(struct workqueue_attrs *attrs);
|
|
int apply_workqueue_attrs(struct workqueue_struct *wq,
|
|
const struct workqueue_attrs *attrs);
|
|
extern int workqueue_unbound_exclude_cpumask(cpumask_var_t cpumask);
|
|
|
|
extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
|
|
struct work_struct *work);
|
|
extern bool queue_work_node(int node, struct workqueue_struct *wq,
|
|
struct work_struct *work);
|
|
extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
|
|
struct delayed_work *work, unsigned long delay);
|
|
extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
|
|
struct delayed_work *dwork, unsigned long delay);
|
|
extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork);
|
|
|
|
extern void __flush_workqueue(struct workqueue_struct *wq);
|
|
extern void drain_workqueue(struct workqueue_struct *wq);
|
|
|
|
extern int schedule_on_each_cpu(work_func_t func);
|
|
|
|
int execute_in_process_context(work_func_t fn, struct execute_work *);
|
|
|
|
extern bool flush_work(struct work_struct *work);
|
|
extern bool cancel_work(struct work_struct *work);
|
|
extern bool cancel_work_sync(struct work_struct *work);
|
|
|
|
extern bool flush_delayed_work(struct delayed_work *dwork);
|
|
extern bool cancel_delayed_work(struct delayed_work *dwork);
|
|
extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
|
|
|
|
extern bool flush_rcu_work(struct rcu_work *rwork);
|
|
|
|
extern void workqueue_set_max_active(struct workqueue_struct *wq,
|
|
int max_active);
|
|
extern void workqueue_set_min_active(struct workqueue_struct *wq,
|
|
int min_active);
|
|
extern struct work_struct *current_work(void);
|
|
extern bool current_is_workqueue_rescuer(void);
|
|
extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
|
|
extern unsigned int work_busy(struct work_struct *work);
|
|
extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
|
|
extern void print_worker_info(const char *log_lvl, struct task_struct *task);
|
|
extern void show_all_workqueues(void);
|
|
extern void show_freezable_workqueues(void);
|
|
extern void show_one_workqueue(struct workqueue_struct *wq);
|
|
extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task);
|
|
|
|
/**
|
|
* queue_work - queue work on a workqueue
|
|
* @wq: workqueue to use
|
|
* @work: work to queue
|
|
*
|
|
* Returns %false if @work was already on a queue, %true 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.
|
|
*
|
|
* Memory-ordering properties: If it returns %true, guarantees that all stores
|
|
* preceding the call to queue_work() in the program order will be visible from
|
|
* the CPU which will execute @work by the time such work executes, e.g.,
|
|
*
|
|
* { x is initially 0 }
|
|
*
|
|
* CPU0 CPU1
|
|
*
|
|
* WRITE_ONCE(x, 1); [ @work is being executed ]
|
|
* r0 = queue_work(wq, work); r1 = READ_ONCE(x);
|
|
*
|
|
* Forbids: r0 == true && r1 == 0
|
|
*/
|
|
static inline bool queue_work(struct workqueue_struct *wq,
|
|
struct work_struct *work)
|
|
{
|
|
return queue_work_on(WORK_CPU_UNBOUND, wq, 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
|
|
*
|
|
* Equivalent to queue_delayed_work_on() but tries to use the local CPU.
|
|
*/
|
|
static inline bool queue_delayed_work(struct workqueue_struct *wq,
|
|
struct delayed_work *dwork,
|
|
unsigned long delay)
|
|
{
|
|
return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
|
|
}
|
|
|
|
/**
|
|
* mod_delayed_work - modify delay of or queue a delayed work
|
|
* @wq: workqueue to use
|
|
* @dwork: work to queue
|
|
* @delay: number of jiffies to wait before queueing
|
|
*
|
|
* mod_delayed_work_on() on local CPU.
|
|
*/
|
|
static inline bool mod_delayed_work(struct workqueue_struct *wq,
|
|
struct delayed_work *dwork,
|
|
unsigned long delay)
|
|
{
|
|
return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
static inline bool schedule_work_on(int cpu, struct work_struct *work)
|
|
{
|
|
return queue_work_on(cpu, system_wq, work);
|
|
}
|
|
|
|
/**
|
|
* schedule_work - put work task in global workqueue
|
|
* @work: job to be done
|
|
*
|
|
* Returns %false if @work was already on the kernel-global workqueue and
|
|
* %true otherwise.
|
|
*
|
|
* This puts a job in the kernel-global workqueue if it was not already
|
|
* queued and leaves it in the same position on the kernel-global
|
|
* workqueue otherwise.
|
|
*
|
|
* Shares the same memory-ordering properties of queue_work(), cf. the
|
|
* DocBook header of queue_work().
|
|
*/
|
|
static inline bool schedule_work(struct work_struct *work)
|
|
{
|
|
return queue_work(system_wq, work);
|
|
}
|
|
|
|
/*
|
|
* Detect attempt to flush system-wide workqueues at compile time when possible.
|
|
* Warn attempt to flush system-wide workqueues at runtime.
|
|
*
|
|
* See https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp
|
|
* for reasons and steps for converting system-wide workqueues into local workqueues.
|
|
*/
|
|
extern void __warn_flushing_systemwide_wq(void)
|
|
__compiletime_warning("Please avoid flushing system-wide workqueues.");
|
|
|
|
/* Please stop using this function, for this function will be removed in near future. */
|
|
#define flush_scheduled_work() \
|
|
({ \
|
|
__warn_flushing_systemwide_wq(); \
|
|
__flush_workqueue(system_wq); \
|
|
})
|
|
|
|
#define flush_workqueue(wq) \
|
|
({ \
|
|
struct workqueue_struct *_wq = (wq); \
|
|
\
|
|
if ((__builtin_constant_p(_wq == system_wq) && \
|
|
_wq == system_wq) || \
|
|
(__builtin_constant_p(_wq == system_highpri_wq) && \
|
|
_wq == system_highpri_wq) || \
|
|
(__builtin_constant_p(_wq == system_long_wq) && \
|
|
_wq == system_long_wq) || \
|
|
(__builtin_constant_p(_wq == system_unbound_wq) && \
|
|
_wq == system_unbound_wq) || \
|
|
(__builtin_constant_p(_wq == system_freezable_wq) && \
|
|
_wq == system_freezable_wq) || \
|
|
(__builtin_constant_p(_wq == system_power_efficient_wq) && \
|
|
_wq == system_power_efficient_wq) || \
|
|
(__builtin_constant_p(_wq == system_freezable_power_efficient_wq) && \
|
|
_wq == system_freezable_power_efficient_wq)) \
|
|
__warn_flushing_systemwide_wq(); \
|
|
__flush_workqueue(_wq); \
|
|
})
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
|
|
unsigned long delay)
|
|
{
|
|
return queue_delayed_work_on(cpu, system_wq, dwork, delay);
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
static inline bool schedule_delayed_work(struct delayed_work *dwork,
|
|
unsigned long delay)
|
|
{
|
|
return queue_delayed_work(system_wq, dwork, delay);
|
|
}
|
|
|
|
#ifndef CONFIG_SMP
|
|
static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
|
|
{
|
|
return fn(arg);
|
|
}
|
|
static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
|
|
{
|
|
return fn(arg);
|
|
}
|
|
#else
|
|
long work_on_cpu_key(int cpu, long (*fn)(void *),
|
|
void *arg, struct lock_class_key *key);
|
|
/*
|
|
* A new key is defined for each caller to make sure the work
|
|
* associated with the function doesn't share its locking class.
|
|
*/
|
|
#define work_on_cpu(_cpu, _fn, _arg) \
|
|
({ \
|
|
static struct lock_class_key __key; \
|
|
\
|
|
work_on_cpu_key(_cpu, _fn, _arg, &__key); \
|
|
})
|
|
|
|
long work_on_cpu_safe_key(int cpu, long (*fn)(void *),
|
|
void *arg, struct lock_class_key *key);
|
|
|
|
/*
|
|
* A new key is defined for each caller to make sure the work
|
|
* associated with the function doesn't share its locking class.
|
|
*/
|
|
#define work_on_cpu_safe(_cpu, _fn, _arg) \
|
|
({ \
|
|
static struct lock_class_key __key; \
|
|
\
|
|
work_on_cpu_safe_key(_cpu, _fn, _arg, &__key); \
|
|
})
|
|
#endif /* CONFIG_SMP */
|
|
|
|
#ifdef CONFIG_FREEZER
|
|
extern void freeze_workqueues_begin(void);
|
|
extern bool freeze_workqueues_busy(void);
|
|
extern void thaw_workqueues(void);
|
|
#endif /* CONFIG_FREEZER */
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
int workqueue_sysfs_register(struct workqueue_struct *wq);
|
|
#else /* CONFIG_SYSFS */
|
|
static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
|
|
{ return 0; }
|
|
#endif /* CONFIG_SYSFS */
|
|
|
|
#ifdef CONFIG_WQ_WATCHDOG
|
|
void wq_watchdog_touch(int cpu);
|
|
#else /* CONFIG_WQ_WATCHDOG */
|
|
static inline void wq_watchdog_touch(int cpu) { }
|
|
#endif /* CONFIG_WQ_WATCHDOG */
|
|
|
|
#ifdef CONFIG_SMP
|
|
int workqueue_prepare_cpu(unsigned int cpu);
|
|
int workqueue_online_cpu(unsigned int cpu);
|
|
int workqueue_offline_cpu(unsigned int cpu);
|
|
#endif
|
|
|
|
void __init workqueue_init_early(void);
|
|
void __init workqueue_init(void);
|
|
void __init workqueue_init_topology(void);
|
|
|
|
#endif
|