/*
* Copyright (C) 2007 Oracle. All rights reserved.
+ * Copyright (C) 2014 Fujitsu. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
+#include <linux/workqueue.h>
#include "async-thread.h"
+#include "ctree.h"
+
+#define WORK_DONE_BIT 0
+#define WORK_ORDER_DONE_BIT 1
+#define WORK_HIGH_PRIO_BIT 2
+
+#define NO_THRESHOLD (-1)
+#define DFT_THRESHOLD (32)
+
+struct __btrfs_workqueue {
+ struct workqueue_struct *normal_wq;
+ /* List head pointing to ordered work list */
+ struct list_head ordered_list;
+
+ /* Spinlock for ordered_list */
+ spinlock_t list_lock;
+
+ /* Thresholding related variants */
+ atomic_t pending;
+ int max_active;
+ int current_max;
+ int thresh;
+ unsigned int count;
+ spinlock_t thres_lock;
+};
-#define WORK_QUEUED_BIT 0
-#define WORK_DONE_BIT 1
-#define WORK_ORDER_DONE_BIT 2
-#define WORK_HIGH_PRIO_BIT 3
-
-/*
- * container for the kthread task pointer and the list of pending work
- * One of these is allocated per thread.
- */
-struct btrfs_worker_thread {
- /* pool we belong to */
- struct btrfs_workers *workers;
-
- /* list of struct btrfs_work that are waiting for service */
- struct list_head pending;
- struct list_head prio_pending;
-
- /* list of worker threads from struct btrfs_workers */
- struct list_head worker_list;
-
- /* kthread */
- struct task_struct *task;
+struct btrfs_workqueue {
+ struct __btrfs_workqueue *normal;
+ struct __btrfs_workqueue *high;
+};
- /* number of things on the pending list */
- atomic_t num_pending;
+static inline struct __btrfs_workqueue
+*__btrfs_alloc_workqueue(const char *name, int flags, int max_active,
+ int thresh)
+{
+ struct __btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_NOFS);
- /* reference counter for this struct */
- atomic_t refs;
+ if (unlikely(!ret))
+ return NULL;
- unsigned long sequence;
+ ret->max_active = max_active;
+ atomic_set(&ret->pending, 0);
+ if (thresh == 0)
+ thresh = DFT_THRESHOLD;
+ /* For low threshold, disabling threshold is a better choice */
+ if (thresh < DFT_THRESHOLD) {
+ ret->current_max = max_active;
+ ret->thresh = NO_THRESHOLD;
+ } else {
+ ret->current_max = 1;
+ ret->thresh = thresh;
+ }
- /* protects the pending list. */
- spinlock_t lock;
+ if (flags & WQ_HIGHPRI)
+ ret->normal_wq = alloc_workqueue("%s-%s-high", flags,
+ ret->max_active,
+ "btrfs", name);
+ else
+ ret->normal_wq = alloc_workqueue("%s-%s", flags,
+ ret->max_active, "btrfs",
+ name);
+ if (unlikely(!ret->normal_wq)) {
+ kfree(ret);
+ return NULL;
+ }
- /* set to non-zero when this thread is already awake and kicking */
- int working;
+ INIT_LIST_HEAD(&ret->ordered_list);
+ spin_lock_init(&ret->list_lock);
+ spin_lock_init(&ret->thres_lock);
+ trace_btrfs_workqueue_alloc(ret, name, flags & WQ_HIGHPRI);
+ return ret;
+}
- /* are we currently idle */
- int idle;
-};
+static inline void
+__btrfs_destroy_workqueue(struct __btrfs_workqueue *wq);
-static int __btrfs_start_workers(struct btrfs_workers *workers);
+struct btrfs_workqueue *btrfs_alloc_workqueue(const char *name,
+ int flags,
+ int max_active,
+ int thresh)
+{
+ struct btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_NOFS);
-/*
- * btrfs_start_workers uses kthread_run, which can block waiting for memory
- * for a very long time. It will actually throttle on page writeback,
- * and so it may not make progress until after our btrfs worker threads
- * process all of the pending work structs in their queue
- *
- * This means we can't use btrfs_start_workers from inside a btrfs worker
- * thread that is used as part of cleaning dirty memory, which pretty much
- * involves all of the worker threads.
- *
- * Instead we have a helper queue who never has more than one thread
- * where we scheduler thread start operations. This worker_start struct
- * is used to contain the work and hold a pointer to the queue that needs
- * another worker.
- */
-struct worker_start {
- struct btrfs_work work;
- struct btrfs_workers *queue;
-};
+ if (unlikely(!ret))
+ return NULL;
-static void start_new_worker_func(struct btrfs_work *work)
-{
- struct worker_start *start;
- start = container_of(work, struct worker_start, work);
- __btrfs_start_workers(start->queue);
- kfree(start);
-}
+ ret->normal = __btrfs_alloc_workqueue(name, flags & ~WQ_HIGHPRI,
+ max_active, thresh);
+ if (unlikely(!ret->normal)) {
+ kfree(ret);
+ return NULL;
+ }
-/*
- * helper function to move a thread onto the idle list after it
- * has finished some requests.
- */
-static void check_idle_worker(struct btrfs_worker_thread *worker)
-{
- if (!worker->idle && atomic_read(&worker->num_pending) <
- worker->workers->idle_thresh / 2) {
- unsigned long flags;
- spin_lock_irqsave(&worker->workers->lock, flags);
- worker->idle = 1;
-
- /* the list may be empty if the worker is just starting */
- if (!list_empty(&worker->worker_list) &&
- !worker->workers->stopping) {
- list_move(&worker->worker_list,
- &worker->workers->idle_list);
+ if (flags & WQ_HIGHPRI) {
+ ret->high = __btrfs_alloc_workqueue(name, flags, max_active,
+ thresh);
+ if (unlikely(!ret->high)) {
+ __btrfs_destroy_workqueue(ret->normal);
+ kfree(ret);
+ return NULL;
}
- spin_unlock_irqrestore(&worker->workers->lock, flags);
}
+ return ret;
}
/*
- * helper function to move a thread off the idle list after new
- * pending work is added.
+ * Hook for threshold which will be called in btrfs_queue_work.
+ * This hook WILL be called in IRQ handler context,
+ * so workqueue_set_max_active MUST NOT be called in this hook
*/
-static void check_busy_worker(struct btrfs_worker_thread *worker)
+static inline void thresh_queue_hook(struct __btrfs_workqueue *wq)
{
- if (worker->idle && atomic_read(&worker->num_pending) >=
- worker->workers->idle_thresh) {
- unsigned long flags;
- spin_lock_irqsave(&worker->workers->lock, flags);
- worker->idle = 0;
-
- if (!list_empty(&worker->worker_list) &&
- !worker->workers->stopping) {
- list_move_tail(&worker->worker_list,
- &worker->workers->worker_list);
- }
- spin_unlock_irqrestore(&worker->workers->lock, flags);
- }
+ if (wq->thresh == NO_THRESHOLD)
+ return;
+ atomic_inc(&wq->pending);
}
-static void check_pending_worker_creates(struct btrfs_worker_thread *worker)
+/*
+ * Hook for threshold which will be called before executing the work,
+ * This hook is called in kthread content.
+ * So workqueue_set_max_active is called here.
+ */
+static inline void thresh_exec_hook(struct __btrfs_workqueue *wq)
{
- struct btrfs_workers *workers = worker->workers;
- struct worker_start *start;
- unsigned long flags;
+ int new_max_active;
+ long pending;
+ int need_change = 0;
- rmb();
- if (!workers->atomic_start_pending)
+ if (wq->thresh == NO_THRESHOLD)
return;
- start = kzalloc(sizeof(*start), GFP_NOFS);
- if (!start)
- return;
-
- start->work.func = start_new_worker_func;
- start->queue = workers;
-
- spin_lock_irqsave(&workers->lock, flags);
- if (!workers->atomic_start_pending)
- goto out;
-
- workers->atomic_start_pending = 0;
- if (workers->num_workers + workers->num_workers_starting >=
- workers->max_workers)
- goto out;
-
- workers->num_workers_starting += 1;
- spin_unlock_irqrestore(&workers->lock, flags);
- btrfs_queue_worker(workers->atomic_worker_start, &start->work);
- return;
+ atomic_dec(&wq->pending);
+ spin_lock(&wq->thres_lock);
+ /*
+ * Use wq->count to limit the calling frequency of
+ * workqueue_set_max_active.
+ */
+ wq->count++;
+ wq->count %= (wq->thresh / 4);
+ if (!wq->count)
+ goto out;
+ new_max_active = wq->current_max;
+ /*
+ * pending may be changed later, but it's OK since we really
+ * don't need it so accurate to calculate new_max_active.
+ */
+ pending = atomic_read(&wq->pending);
+ if (pending > wq->thresh)
+ new_max_active++;
+ if (pending < wq->thresh / 2)
+ new_max_active--;
+ new_max_active = clamp_val(new_max_active, 1, wq->max_active);
+ if (new_max_active != wq->current_max) {
+ need_change = 1;
+ wq->current_max = new_max_active;
+ }
out:
- kfree(start);
- spin_unlock_irqrestore(&workers->lock, flags);
+ spin_unlock(&wq->thres_lock);
+
+ if (need_change) {
+ workqueue_set_max_active(wq->normal_wq, wq->current_max);
+ }
}
-static noinline void run_ordered_completions(struct btrfs_workers *workers,
- struct btrfs_work *work)
+static void run_ordered_work(struct __btrfs_workqueue *wq)
{
- if (!workers->ordered)
- return;
-
- set_bit(WORK_DONE_BIT, &work->flags);
-
- spin_lock(&workers->order_lock);
+ struct list_head *list = &wq->ordered_list;
+ struct btrfs_work *work;
+ spinlock_t *lock = &wq->list_lock;
+ unsigned long flags;
while (1) {
- if (!list_empty(&workers->prio_order_list)) {
- work = list_entry(workers->prio_order_list.next,
- struct btrfs_work, order_list);
- } else if (!list_empty(&workers->order_list)) {
- work = list_entry(workers->order_list.next,
- struct btrfs_work, order_list);
- } else {
+ spin_lock_irqsave(lock, flags);
+ if (list_empty(list))
break;
- }
+ work = list_entry(list->next, struct btrfs_work,
+ ordered_list);
if (!test_bit(WORK_DONE_BIT, &work->flags))
break;
- /* we are going to call the ordered done function, but
+ /*
+ * we are going to call the ordered done function, but
* we leave the work item on the list as a barrier so
* that later work items that are done don't have their
* functions called before this one returns
*/
if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags))
break;
-
- spin_unlock(&workers->order_lock);
-
+ trace_btrfs_ordered_sched(work);
+ spin_unlock_irqrestore(lock, flags);
work->ordered_func(work);
/* now take the lock again and drop our item from the list */
- spin_lock(&workers->order_lock);
- list_del(&work->order_list);
- spin_unlock(&workers->order_lock);
+ spin_lock_irqsave(lock, flags);
+ list_del(&work->ordered_list);
+ spin_unlock_irqrestore(lock, flags);
/*
* we don't want to call the ordered free functions
* with the lock held though
*/
work->ordered_free(work);
- spin_lock(&workers->order_lock);
- }
-
- spin_unlock(&workers->order_lock);
-}
-
-static void put_worker(struct btrfs_worker_thread *worker)
-{
- if (atomic_dec_and_test(&worker->refs))
- kfree(worker);
-}
-
-static int try_worker_shutdown(struct btrfs_worker_thread *worker)
-{
- int freeit = 0;
-
- spin_lock_irq(&worker->lock);
- spin_lock(&worker->workers->lock);
- if (worker->workers->num_workers > 1 &&
- worker->idle &&
- !worker->working &&
- !list_empty(&worker->worker_list) &&
- list_empty(&worker->prio_pending) &&
- list_empty(&worker->pending) &&
- atomic_read(&worker->num_pending) == 0) {
- freeit = 1;
- list_del_init(&worker->worker_list);
- worker->workers->num_workers--;
+ trace_btrfs_all_work_done(work);
}
- spin_unlock(&worker->workers->lock);
- spin_unlock_irq(&worker->lock);
-
- if (freeit)
- put_worker(worker);
- return freeit;
+ spin_unlock_irqrestore(lock, flags);
}
-static struct btrfs_work *get_next_work(struct btrfs_worker_thread *worker,
- struct list_head *prio_head,
- struct list_head *head)
-{
- struct btrfs_work *work = NULL;
- struct list_head *cur = NULL;
-
- if (!list_empty(prio_head))
- cur = prio_head->next;
-
- smp_mb();
- if (!list_empty(&worker->prio_pending))
- goto refill;
-
- if (!list_empty(head))
- cur = head->next;
-
- if (cur)
- goto out;
-
-refill:
- spin_lock_irq(&worker->lock);
- list_splice_tail_init(&worker->prio_pending, prio_head);
- list_splice_tail_init(&worker->pending, head);
-
- if (!list_empty(prio_head))
- cur = prio_head->next;
- else if (!list_empty(head))
- cur = head->next;
- spin_unlock_irq(&worker->lock);
-
- if (!cur)
- goto out_fail;
-
-out:
- work = list_entry(cur, struct btrfs_work, list);
-
-out_fail:
- return work;
-}
-
-/*
- * main loop for servicing work items
- */
-static int worker_loop(void *arg)
+static void normal_work_helper(struct work_struct *arg)
{
- struct btrfs_worker_thread *worker = arg;
- struct list_head head;
- struct list_head prio_head;
struct btrfs_work *work;
+ struct __btrfs_workqueue *wq;
+ int need_order = 0;
- INIT_LIST_HEAD(&head);
- INIT_LIST_HEAD(&prio_head);
-
- do {
-again:
- while (1) {
-
-
- work = get_next_work(worker, &prio_head, &head);
- if (!work)
- break;
-
- list_del(&work->list);
- clear_bit(WORK_QUEUED_BIT, &work->flags);
-
- work->worker = worker;
-
- work->func(work);
-
- atomic_dec(&worker->num_pending);
- /*
- * unless this is an ordered work queue,
- * 'work' was probably freed by func above.
- */
- run_ordered_completions(worker->workers, work);
-
- check_pending_worker_creates(worker);
- cond_resched();
- }
-
- spin_lock_irq(&worker->lock);
- check_idle_worker(worker);
-
- if (freezing(current)) {
- worker->working = 0;
- spin_unlock_irq(&worker->lock);
- try_to_freeze();
- } else {
- spin_unlock_irq(&worker->lock);
- if (!kthread_should_stop()) {
- cpu_relax();
- /*
- * we've dropped the lock, did someone else
- * jump_in?
- */
- smp_mb();
- if (!list_empty(&worker->pending) ||
- !list_empty(&worker->prio_pending))
- continue;
-
- /*
- * this short schedule allows more work to
- * come in without the queue functions
- * needing to go through wake_up_process()
- *
- * worker->working is still 1, so nobody
- * is going to try and wake us up
- */
- schedule_timeout(1);
- smp_mb();
- if (!list_empty(&worker->pending) ||
- !list_empty(&worker->prio_pending))
- continue;
-
- if (kthread_should_stop())
- break;
-
- /* still no more work?, sleep for real */
- spin_lock_irq(&worker->lock);
- set_current_state(TASK_INTERRUPTIBLE);
- if (!list_empty(&worker->pending) ||
- !list_empty(&worker->prio_pending)) {
- spin_unlock_irq(&worker->lock);
- set_current_state(TASK_RUNNING);
- goto again;
- }
-
- /*
- * this makes sure we get a wakeup when someone
- * adds something new to the queue
- */
- worker->working = 0;
- spin_unlock_irq(&worker->lock);
-
- if (!kthread_should_stop()) {
- schedule_timeout(HZ * 120);
- if (!worker->working &&
- try_worker_shutdown(worker)) {
- return 0;
- }
- }
- }
- __set_current_state(TASK_RUNNING);
- }
- } while (!kthread_should_stop());
- return 0;
-}
-
-/*
- * this will wait for all the worker threads to shutdown
- */
-void btrfs_stop_workers(struct btrfs_workers *workers)
-{
- struct list_head *cur;
- struct btrfs_worker_thread *worker;
- int can_stop;
-
- spin_lock_irq(&workers->lock);
- workers->stopping = 1;
- list_splice_init(&workers->idle_list, &workers->worker_list);
- while (!list_empty(&workers->worker_list)) {
- cur = workers->worker_list.next;
- worker = list_entry(cur, struct btrfs_worker_thread,
- worker_list);
-
- atomic_inc(&worker->refs);
- workers->num_workers -= 1;
- if (!list_empty(&worker->worker_list)) {
- list_del_init(&worker->worker_list);
- put_worker(worker);
- can_stop = 1;
- } else
- can_stop = 0;
- spin_unlock_irq(&workers->lock);
- if (can_stop)
- kthread_stop(worker->task);
- spin_lock_irq(&workers->lock);
- put_worker(worker);
+ work = container_of(arg, struct btrfs_work, normal_work);
+ /*
+ * We should not touch things inside work in the following cases:
+ * 1) after work->func() if it has no ordered_free
+ * Since the struct is freed in work->func().
+ * 2) after setting WORK_DONE_BIT
+ * The work may be freed in other threads almost instantly.
+ * So we save the needed things here.
+ */
+ if (work->ordered_func)
+ need_order = 1;
+ wq = work->wq;
+
+ trace_btrfs_work_sched(work);
+ thresh_exec_hook(wq);
+ work->func(work);
+ if (need_order) {
+ set_bit(WORK_DONE_BIT, &work->flags);
+ run_ordered_work(wq);
}
- spin_unlock_irq(&workers->lock);
+ if (!need_order)
+ trace_btrfs_all_work_done(work);
}
-/*
- * simple init on struct btrfs_workers
- */
-void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max,
- struct btrfs_workers *async_helper)
+void btrfs_init_work(struct btrfs_work *work,
+ btrfs_func_t func,
+ btrfs_func_t ordered_func,
+ btrfs_func_t ordered_free)
{
- workers->num_workers = 0;
- workers->num_workers_starting = 0;
- INIT_LIST_HEAD(&workers->worker_list);
- INIT_LIST_HEAD(&workers->idle_list);
- INIT_LIST_HEAD(&workers->order_list);
- INIT_LIST_HEAD(&workers->prio_order_list);
- spin_lock_init(&workers->lock);
- spin_lock_init(&workers->order_lock);
- workers->max_workers = max;
- workers->idle_thresh = 32;
- workers->name = name;
- workers->ordered = 0;
- workers->atomic_start_pending = 0;
- workers->atomic_worker_start = async_helper;
- workers->stopping = 0;
+ work->func = func;
+ work->ordered_func = ordered_func;
+ work->ordered_free = ordered_free;
+ INIT_WORK(&work->normal_work, normal_work_helper);
+ INIT_LIST_HEAD(&work->ordered_list);
+ work->flags = 0;
}
-/*
- * starts new worker threads. This does not enforce the max worker
- * count in case you need to temporarily go past it.
- */
-static int __btrfs_start_workers(struct btrfs_workers *workers)
+static inline void __btrfs_queue_work(struct __btrfs_workqueue *wq,
+ struct btrfs_work *work)
{
- struct btrfs_worker_thread *worker;
- int ret = 0;
-
- worker = kzalloc(sizeof(*worker), GFP_NOFS);
- if (!worker) {
- ret = -ENOMEM;
- goto fail;
- }
-
- INIT_LIST_HEAD(&worker->pending);
- INIT_LIST_HEAD(&worker->prio_pending);
- INIT_LIST_HEAD(&worker->worker_list);
- spin_lock_init(&worker->lock);
-
- atomic_set(&worker->num_pending, 0);
- atomic_set(&worker->refs, 1);
- worker->workers = workers;
- worker->task = kthread_create(worker_loop, worker,
- "btrfs-%s-%d", workers->name,
- workers->num_workers + 1);
- if (IS_ERR(worker->task)) {
- ret = PTR_ERR(worker->task);
- goto fail;
- }
+ unsigned long flags;
- spin_lock_irq(&workers->lock);
- if (workers->stopping) {
- spin_unlock_irq(&workers->lock);
- ret = -EINVAL;
- goto fail_kthread;
+ work->wq = wq;
+ thresh_queue_hook(wq);
+ if (work->ordered_func) {
+ spin_lock_irqsave(&wq->list_lock, flags);
+ list_add_tail(&work->ordered_list, &wq->ordered_list);
+ spin_unlock_irqrestore(&wq->list_lock, flags);
}
- list_add_tail(&worker->worker_list, &workers->idle_list);
- worker->idle = 1;
- workers->num_workers++;
- workers->num_workers_starting--;
- WARN_ON(workers->num_workers_starting < 0);
- spin_unlock_irq(&workers->lock);
-
- wake_up_process(worker->task);
- return 0;
-
-fail_kthread:
- kthread_stop(worker->task);
-fail:
- kfree(worker);
- spin_lock_irq(&workers->lock);
- workers->num_workers_starting--;
- spin_unlock_irq(&workers->lock);
- return ret;
+ queue_work(wq->normal_wq, &work->normal_work);
+ trace_btrfs_work_queued(work);
}
-int btrfs_start_workers(struct btrfs_workers *workers)
+void btrfs_queue_work(struct btrfs_workqueue *wq,
+ struct btrfs_work *work)
{
- spin_lock_irq(&workers->lock);
- workers->num_workers_starting++;
- spin_unlock_irq(&workers->lock);
- return __btrfs_start_workers(workers);
-}
-
-/*
- * run through the list and find a worker thread that doesn't have a lot
- * to do right now. This can return null if we aren't yet at the thread
- * count limit and all of the threads are busy.
- */
-static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers)
-{
- struct btrfs_worker_thread *worker;
- struct list_head *next;
- int enforce_min;
-
- enforce_min = (workers->num_workers + workers->num_workers_starting) <
- workers->max_workers;
-
- /*
- * if we find an idle thread, don't move it to the end of the
- * idle list. This improves the chance that the next submission
- * will reuse the same thread, and maybe catch it while it is still
- * working
- */
- if (!list_empty(&workers->idle_list)) {
- next = workers->idle_list.next;
- worker = list_entry(next, struct btrfs_worker_thread,
- worker_list);
- return worker;
- }
- if (enforce_min || list_empty(&workers->worker_list))
- return NULL;
-
- /*
- * if we pick a busy task, move the task to the end of the list.
- * hopefully this will keep things somewhat evenly balanced.
- * Do the move in batches based on the sequence number. This groups
- * requests submitted at roughly the same time onto the same worker.
- */
- next = workers->worker_list.next;
- worker = list_entry(next, struct btrfs_worker_thread, worker_list);
- worker->sequence++;
+ struct __btrfs_workqueue *dest_wq;
- if (worker->sequence % workers->idle_thresh == 0)
- list_move_tail(next, &workers->worker_list);
- return worker;
+ if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags) && wq->high)
+ dest_wq = wq->high;
+ else
+ dest_wq = wq->normal;
+ __btrfs_queue_work(dest_wq, work);
}
-/*
- * selects a worker thread to take the next job. This will either find
- * an idle worker, start a new worker up to the max count, or just return
- * one of the existing busy workers.
- */
-static struct btrfs_worker_thread *find_worker(struct btrfs_workers *workers)
+static inline void
+__btrfs_destroy_workqueue(struct __btrfs_workqueue *wq)
{
- struct btrfs_worker_thread *worker;
- unsigned long flags;
- struct list_head *fallback;
- int ret;
-
- spin_lock_irqsave(&workers->lock, flags);
-again:
- worker = next_worker(workers);
-
- if (!worker) {
- if (workers->num_workers + workers->num_workers_starting >=
- workers->max_workers) {
- goto fallback;
- } else if (workers->atomic_worker_start) {
- workers->atomic_start_pending = 1;
- goto fallback;
- } else {
- workers->num_workers_starting++;
- spin_unlock_irqrestore(&workers->lock, flags);
- /* we're below the limit, start another worker */
- ret = __btrfs_start_workers(workers);
- spin_lock_irqsave(&workers->lock, flags);
- if (ret)
- goto fallback;
- goto again;
- }
- }
- goto found;
-
-fallback:
- fallback = NULL;
- /*
- * we have failed to find any workers, just
- * return the first one we can find.
- */
- if (!list_empty(&workers->worker_list))
- fallback = workers->worker_list.next;
- if (!list_empty(&workers->idle_list))
- fallback = workers->idle_list.next;
- BUG_ON(!fallback);
- worker = list_entry(fallback,
- struct btrfs_worker_thread, worker_list);
-found:
- /*
- * this makes sure the worker doesn't exit before it is placed
- * onto a busy/idle list
- */
- atomic_inc(&worker->num_pending);
- spin_unlock_irqrestore(&workers->lock, flags);
- return worker;
+ destroy_workqueue(wq->normal_wq);
+ trace_btrfs_workqueue_destroy(wq);
+ kfree(wq);
}
-/*
- * btrfs_requeue_work just puts the work item back on the tail of the list
- * it was taken from. It is intended for use with long running work functions
- * that make some progress and want to give the cpu up for others.
- */
-void btrfs_requeue_work(struct btrfs_work *work)
+void btrfs_destroy_workqueue(struct btrfs_workqueue *wq)
{
- struct btrfs_worker_thread *worker = work->worker;
- unsigned long flags;
- int wake = 0;
-
- if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
+ if (!wq)
return;
-
- spin_lock_irqsave(&worker->lock, flags);
- if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags))
- list_add_tail(&work->list, &worker->prio_pending);
- else
- list_add_tail(&work->list, &worker->pending);
- atomic_inc(&worker->num_pending);
-
- /* by definition we're busy, take ourselves off the idle
- * list
- */
- if (worker->idle) {
- spin_lock(&worker->workers->lock);
- worker->idle = 0;
- list_move_tail(&worker->worker_list,
- &worker->workers->worker_list);
- spin_unlock(&worker->workers->lock);
- }
- if (!worker->working) {
- wake = 1;
- worker->working = 1;
- }
-
- if (wake)
- wake_up_process(worker->task);
- spin_unlock_irqrestore(&worker->lock, flags);
+ if (wq->high)
+ __btrfs_destroy_workqueue(wq->high);
+ __btrfs_destroy_workqueue(wq->normal);
+ kfree(wq);
}
-void btrfs_set_work_high_prio(struct btrfs_work *work)
+void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int max)
{
- set_bit(WORK_HIGH_PRIO_BIT, &work->flags);
+ wq->normal->max_active = max;
+ if (wq->high)
+ wq->high->max_active = max;
}
-/*
- * places a struct btrfs_work into the pending queue of one of the kthreads
- */
-void btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
+void btrfs_set_work_high_priority(struct btrfs_work *work)
{
- struct btrfs_worker_thread *worker;
- unsigned long flags;
- int wake = 0;
-
- /* don't requeue something already on a list */
- if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
- return;
-
- worker = find_worker(workers);
- if (workers->ordered) {
- /*
- * you're not allowed to do ordered queues from an
- * interrupt handler
- */
- spin_lock(&workers->order_lock);
- if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags)) {
- list_add_tail(&work->order_list,
- &workers->prio_order_list);
- } else {
- list_add_tail(&work->order_list, &workers->order_list);
- }
- spin_unlock(&workers->order_lock);
- } else {
- INIT_LIST_HEAD(&work->order_list);
- }
-
- spin_lock_irqsave(&worker->lock, flags);
-
- if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags))
- list_add_tail(&work->list, &worker->prio_pending);
- else
- list_add_tail(&work->list, &worker->pending);
- check_busy_worker(worker);
-
- /*
- * avoid calling into wake_up_process if this thread has already
- * been kicked
- */
- if (!worker->working)
- wake = 1;
- worker->working = 1;
-
- if (wake)
- wake_up_process(worker->task);
- spin_unlock_irqrestore(&worker->lock, flags);
+ set_bit(WORK_HIGH_PRIO_BIT, &work->flags);
}
projects / mirror_ubuntu-bionic-kernel.git / blobdiff