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0a8165d7 | 1 | /* |
7bc09003 JK |
2 | * fs/f2fs/gc.h |
3 | * | |
4 | * Copyright (c) 2012 Samsung Electronics Co., Ltd. | |
5 | * http://www.samsung.com/ | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
7bc09003 JK |
11 | #define GC_THREAD_MIN_WB_PAGES 1 /* |
12 | * a threshold to determine | |
13 | * whether IO subsystem is idle | |
14 | * or not | |
15 | */ | |
16 | #define GC_THREAD_MIN_SLEEP_TIME 10000 /* milliseconds */ | |
17 | #define GC_THREAD_MAX_SLEEP_TIME 30000 | |
18 | #define GC_THREAD_NOGC_SLEEP_TIME 10000 | |
19 | #define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */ | |
20 | #define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */ | |
21 | ||
22 | /* Search max. number of dirty segments to select a victim segment */ | |
23 | #define MAX_VICTIM_SEARCH 20 | |
24 | ||
7bc09003 JK |
25 | struct f2fs_gc_kthread { |
26 | struct task_struct *f2fs_gc_task; | |
27 | wait_queue_head_t gc_wait_queue_head; | |
28 | }; | |
29 | ||
30 | struct inode_entry { | |
31 | struct list_head list; | |
32 | struct inode *inode; | |
33 | }; | |
34 | ||
0a8165d7 | 35 | /* |
7bc09003 JK |
36 | * inline functions |
37 | */ | |
38 | static inline block_t free_user_blocks(struct f2fs_sb_info *sbi) | |
39 | { | |
40 | if (free_segments(sbi) < overprovision_segments(sbi)) | |
41 | return 0; | |
42 | else | |
43 | return (free_segments(sbi) - overprovision_segments(sbi)) | |
44 | << sbi->log_blocks_per_seg; | |
45 | } | |
46 | ||
47 | static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi) | |
48 | { | |
49 | return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100; | |
50 | } | |
51 | ||
52 | static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi) | |
53 | { | |
54 | block_t reclaimable_user_blocks = sbi->user_block_count - | |
55 | written_block_count(sbi); | |
56 | return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100; | |
57 | } | |
58 | ||
59 | static inline long increase_sleep_time(long wait) | |
60 | { | |
61 | wait += GC_THREAD_MIN_SLEEP_TIME; | |
62 | if (wait > GC_THREAD_MAX_SLEEP_TIME) | |
63 | wait = GC_THREAD_MAX_SLEEP_TIME; | |
64 | return wait; | |
65 | } | |
66 | ||
67 | static inline long decrease_sleep_time(long wait) | |
68 | { | |
69 | wait -= GC_THREAD_MIN_SLEEP_TIME; | |
70 | if (wait <= GC_THREAD_MIN_SLEEP_TIME) | |
71 | wait = GC_THREAD_MIN_SLEEP_TIME; | |
72 | return wait; | |
73 | } | |
74 | ||
75 | static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi) | |
76 | { | |
77 | block_t invalid_user_blocks = sbi->user_block_count - | |
78 | written_block_count(sbi); | |
79 | /* | |
80 | * Background GC is triggered with the following condition. | |
81 | * 1. There are a number of invalid blocks. | |
82 | * 2. There is not enough free space. | |
83 | */ | |
84 | if (invalid_user_blocks > limit_invalid_user_blocks(sbi) && | |
85 | free_user_blocks(sbi) < limit_free_user_blocks(sbi)) | |
86 | return true; | |
87 | return false; | |
88 | } | |
89 | ||
90 | static inline int is_idle(struct f2fs_sb_info *sbi) | |
91 | { | |
92 | struct block_device *bdev = sbi->sb->s_bdev; | |
93 | struct request_queue *q = bdev_get_queue(bdev); | |
94 | struct request_list *rl = &q->root_rl; | |
95 | return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]); | |
96 | } |