diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/fork.c | 2 | ||||
-rw-r--r-- | kernel/task_work.c | 64 |
2 files changed, 34 insertions, 32 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index ab5211b9e622..bebabad59202 100644 --- a/kernel/fork.c +++ b/kernel/fork.c | |||
@@ -1415,7 +1415,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, | |||
1415 | */ | 1415 | */ |
1416 | p->group_leader = p; | 1416 | p->group_leader = p; |
1417 | INIT_LIST_HEAD(&p->thread_group); | 1417 | INIT_LIST_HEAD(&p->thread_group); |
1418 | INIT_HLIST_HEAD(&p->task_works); | 1418 | p->task_works = NULL; |
1419 | 1419 | ||
1420 | /* Now that the task is set up, run cgroup callbacks if | 1420 | /* Now that the task is set up, run cgroup callbacks if |
1421 | * necessary. We need to run them before the task is visible | 1421 | * necessary. We need to run them before the task is visible |
diff --git a/kernel/task_work.c b/kernel/task_work.c index 82d1c794066d..9b8948dbdc60 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c | |||
@@ -19,7 +19,12 @@ task_work_add(struct task_struct *task, struct task_work *twork, bool notify) | |||
19 | */ | 19 | */ |
20 | raw_spin_lock_irqsave(&task->pi_lock, flags); | 20 | raw_spin_lock_irqsave(&task->pi_lock, flags); |
21 | if (likely(!(task->flags & PF_EXITING))) { | 21 | if (likely(!(task->flags & PF_EXITING))) { |
22 | hlist_add_head(&twork->hlist, &task->task_works); | 22 | struct task_work *last = task->task_works; |
23 | struct task_work *first = last ? last->next : twork; | ||
24 | twork->next = first; | ||
25 | if (last) | ||
26 | last->next = twork; | ||
27 | task->task_works = twork; | ||
23 | err = 0; | 28 | err = 0; |
24 | } | 29 | } |
25 | raw_spin_unlock_irqrestore(&task->pi_lock, flags); | 30 | raw_spin_unlock_irqrestore(&task->pi_lock, flags); |
@@ -34,51 +39,48 @@ struct task_work * | |||
34 | task_work_cancel(struct task_struct *task, task_work_func_t func) | 39 | task_work_cancel(struct task_struct *task, task_work_func_t func) |
35 | { | 40 | { |
36 | unsigned long flags; | 41 | unsigned long flags; |
37 | struct task_work *twork; | 42 | struct task_work *last, *res = NULL; |
38 | struct hlist_node *pos; | ||
39 | 43 | ||
40 | raw_spin_lock_irqsave(&task->pi_lock, flags); | 44 | raw_spin_lock_irqsave(&task->pi_lock, flags); |
41 | hlist_for_each_entry(twork, pos, &task->task_works, hlist) { | 45 | last = task->task_works; |
42 | if (twork->func == func) { | 46 | if (last) { |
43 | hlist_del(&twork->hlist); | 47 | struct task_work *q = last, *p = q->next; |
44 | goto found; | 48 | while (1) { |
49 | if (p->func == func) { | ||
50 | q->next = p->next; | ||
51 | if (p == last) | ||
52 | task->task_works = q == p ? NULL : q; | ||
53 | res = p; | ||
54 | break; | ||
55 | } | ||
56 | if (p == last) | ||
57 | break; | ||
58 | q = p; | ||
59 | p = q->next; | ||
45 | } | 60 | } |
46 | } | 61 | } |
47 | twork = NULL; | ||
48 | found: | ||
49 | raw_spin_unlock_irqrestore(&task->pi_lock, flags); | 62 | raw_spin_unlock_irqrestore(&task->pi_lock, flags); |
50 | 63 | return res; | |
51 | return twork; | ||
52 | } | 64 | } |
53 | 65 | ||
54 | void task_work_run(void) | 66 | void task_work_run(void) |
55 | { | 67 | { |
56 | struct task_struct *task = current; | 68 | struct task_struct *task = current; |
57 | struct hlist_head task_works; | 69 | struct task_work *p, *q; |
58 | struct hlist_node *pos; | ||
59 | 70 | ||
60 | raw_spin_lock_irq(&task->pi_lock); | 71 | raw_spin_lock_irq(&task->pi_lock); |
61 | hlist_move_list(&task->task_works, &task_works); | 72 | p = task->task_works; |
73 | task->task_works = NULL; | ||
62 | raw_spin_unlock_irq(&task->pi_lock); | 74 | raw_spin_unlock_irq(&task->pi_lock); |
63 | 75 | ||
64 | if (unlikely(hlist_empty(&task_works))) | 76 | if (unlikely(!p)) |
65 | return; | 77 | return; |
66 | /* | ||
67 | * We use hlist to save the space in task_struct, but we want fifo. | ||
68 | * Find the last entry, the list should be short, then process them | ||
69 | * in reverse order. | ||
70 | */ | ||
71 | for (pos = task_works.first; pos->next; pos = pos->next) | ||
72 | ; | ||
73 | |||
74 | for (;;) { | ||
75 | struct hlist_node **pprev = pos->pprev; | ||
76 | struct task_work *twork = container_of(pos, struct task_work, | ||
77 | hlist); | ||
78 | twork->func(twork); | ||
79 | 78 | ||
80 | if (pprev == &task_works.first) | 79 | q = p->next; /* head */ |
81 | break; | 80 | p->next = NULL; /* cut it */ |
82 | pos = container_of(pprev, struct hlist_node, next); | 81 | while (q) { |
82 | p = q->next; | ||
83 | q->func(q); | ||
84 | q = p; | ||
83 | } | 85 | } |
84 | } | 86 | } |