projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 07fe7cb7 DH |
1 | /* Worker thread pool for slow items, such as filesystem lookups or mkdirs |
| 2 | * | |
| 3 | * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. | |
| 4 | * Written by David Howells (dhowells@redhat.com) | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU General Public Licence | |
| 8 | * as published by the Free Software Foundation; either version | |
| 9 | * 2 of the Licence, or (at your option) any later version. | |
| 10 | */ | |
| 11 | ||
| 12 | #ifndef _LINUX_SLOW_WORK_H | |
| 13 | #define _LINUX_SLOW_WORK_H | |
| 14 | ||
| 15 | #ifdef CONFIG_SLOW_WORK | |
| 16 | ||
| 17 | struct slow_work; | |
| 18 | ||
| 19 | /* | |
| 20 | * The operations used to support slow work items | |
| 21 | */ | |
| 22 | struct slow_work_ops { | |
| 23 | /* get a ref on a work item | |
| 24 | * - return 0 if successful, -ve if not | |
| 25 | */ | |
| 26 | int (*get_ref)(struct slow_work *work); | |
| 27 | ||
| 28 | /* discard a ref to a work item */ | |
| 29 | void (*put_ref)(struct slow_work *work); | |
| 30 | ||
| 31 | /* execute a work item */ | |
| 32 | void (*execute)(struct slow_work *work); | |
| 33 | }; | |
| 34 | ||
| 35 | /* | |
| 36 | * A slow work item | |
| 37 | * - A reference is held on the parent object by the thread pool when it is | |
| 38 | * queued | |
| 39 | */ | |
| 40 | struct slow_work { | |
| 41 | unsigned long flags; | |
| 42 | #define SLOW_WORK_PENDING 0 /* item pending (further) execution */ | |
| 43 | #define SLOW_WORK_EXECUTING 1 /* item currently executing */ | |
| 44 | #define SLOW_WORK_ENQ_DEFERRED 2 /* item enqueue deferred */ | |
| 45 | #define SLOW_WORK_VERY_SLOW 3 /* item is very slow */ | |
| 46 | const struct slow_work_ops *ops; /* operations table for this item */ | |
| 47 | struct list_head link; /* link in queue */ | |
| 48 | }; | |
| 49 | ||
| 50 | /** | |
| 51 | * slow_work_init - Initialise a slow work item | |
| 52 | * @work: The work item to initialise | |
| 53 | * @ops: The operations to use to handle the slow work item | |
| 54 | * | |
| 55 | * Initialise a slow work item. | |
| 56 | */ | |
| 57 | static inline void slow_work_init(struct slow_work *work, | |
| 58 | const struct slow_work_ops *ops) | |
| 59 | { | |
| 60 | work->flags = 0; | |
| 61 | work->ops = ops; | |
| 62 | INIT_LIST_HEAD(&work->link); | |
| 63 | } | |
| 64 | ||
| 65 | /** | |
| 66 | * slow_work_init - Initialise a very slow work item | |
| 67 | * @work: The work item to initialise | |
| 68 | * @ops: The operations to use to handle the slow work item | |
| 69 | * | |
| 70 | * Initialise a very slow work item. This item will be restricted such that | |
| 71 | * only a certain number of the pool threads will be able to execute items of | |
| 72 | * this type. | |
| 73 | */ | |
| 74 | static inline void vslow_work_init(struct slow_work *work, | |
| 75 | const struct slow_work_ops *ops) | |
| 76 | { | |
| 77 | work->flags = 1 << SLOW_WORK_VERY_SLOW; | |
| 78 | work->ops = ops; | |
| 79 | INIT_LIST_HEAD(&work->link); | |
| 80 | } | |
| 81 | ||
| 82 | extern int slow_work_enqueue(struct slow_work *work); | |
| 83 | extern int slow_work_register_user(void); | |
| 84 | extern void slow_work_unregister_user(void); | |
| 85 | ||
| 86 | ||
| 87 | #endif /* CONFIG_SLOW_WORK */ | |
| 88 | #endif /* _LINUX_SLOW_WORK_H */ |