[deliverable/linux.git] / fs / f2fs / gc.h

/*
 * fs/f2fs/gc.h
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#define GC_THREAD_MIN_WB_PAGES		1	/*
						 * a threshold to determine
						 * whether IO subsystem is idle
						 * or not
						 */
#define DEF_GC_THREAD_MIN_SLEEP_TIME	30000	/* milliseconds */
#define DEF_GC_THREAD_MAX_SLEEP_TIME	60000
#define DEF_GC_THREAD_NOGC_SLEEP_TIME	300000	/* wait 5 min */
#define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
#define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */

/* Search max. number of dirty segments to select a victim segment */
#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */

struct f2fs_gc_kthread {
	struct task_struct *f2fs_gc_task;
	wait_queue_head_t gc_wait_queue_head;

	/* for gc sleep time */
	unsigned int min_sleep_time;
	unsigned int max_sleep_time;
	unsigned int no_gc_sleep_time;

	/* for changing gc mode */
	unsigned int gc_idle;
};

struct inode_entry {
	struct list_head list;
	struct inode *inode;
};

struct gc_inode_list {
	struct list_head ilist;
	struct radix_tree_root iroot;
};

/*
 * inline functions
 */
static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
{
	if (free_segments(sbi) < overprovision_segments(sbi))
		return 0;
	else
		return (free_segments(sbi) - overprovision_segments(sbi))
			<< sbi->log_blocks_per_seg;
}

static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
{
	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
}

static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
{
	block_t reclaimable_user_blocks = sbi->user_block_count -
		written_block_count(sbi);
	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
}

static inline long increase_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
{
	if (wait == gc_th->no_gc_sleep_time)
		return wait;

	wait += gc_th->min_sleep_time;
	if (wait > gc_th->max_sleep_time)
		wait = gc_th->max_sleep_time;
	return wait;
}

static inline long decrease_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
{
	if (wait == gc_th->no_gc_sleep_time)
		wait = gc_th->max_sleep_time;

	wait -= gc_th->min_sleep_time;
	if (wait <= gc_th->min_sleep_time)
		wait = gc_th->min_sleep_time;
	return wait;
}

static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
{
	block_t invalid_user_blocks = sbi->user_block_count -
					written_block_count(sbi);
	/*
	 * Background GC is triggered with the following conditions.
	 * 1. There are a number of invalid blocks.
	 * 2. There is not enough free space.
	 */
	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
			free_user_blocks(sbi) < limit_free_user_blocks(sbi))
		return true;
	return false;
}

static inline int is_idle(struct f2fs_sb_info *sbi)
{
	struct block_device *bdev = sbi->sb->s_bdev;
	struct request_queue *q = bdev_get_queue(bdev);
	struct request_list *rl = &q->root_rl;
	return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
}
Commit	Line	Data
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	*/
b59d0bae NJ	16	#define DEF_GC_THREAD_MIN_SLEEP_TIME 30000 /* milliseconds */
	17	#define DEF_GC_THREAD_MAX_SLEEP_TIME 60000
	18	#define DEF_GC_THREAD_NOGC_SLEEP_TIME 300000 /* wait 5 min */
7bc09003 JK	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 */
b1c57c1c	23	#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
7bc09003	24
7bc09003 JK	25	struct f2fs_gc_kthread {
	26	struct task_struct *f2fs_gc_task;
	27	wait_queue_head_t gc_wait_queue_head;
b59d0bae NJ	28
	29	/* for gc sleep time */
	30	unsigned int min_sleep_time;
	31	unsigned int max_sleep_time;
	32	unsigned int no_gc_sleep_time;
d2dc095f NJ	33
	34	/* for changing gc mode */
	35	unsigned int gc_idle;
7bc09003 JK	36	};
	37
	38	struct inode_entry {
	39	struct list_head list;
	40	struct inode *inode;
	41	};
	42
7dda2af8 CL	43	struct gc_inode_list {
	44	struct list_head ilist;
	45	struct radix_tree_root iroot;
	46	};
	47
0a8165d7	48	/*
7bc09003 JK	49	* inline functions
	50	*/
	51	static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
	52	{
	53	if (free_segments(sbi) < overprovision_segments(sbi))
	54	return 0;
	55	else
	56	return (free_segments(sbi) - overprovision_segments(sbi))
	57	<< sbi->log_blocks_per_seg;
	58	}
	59
	60	static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
	61	{
	62	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
	63	}
	64
	65	static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
	66	{
	67	block_t reclaimable_user_blocks = sbi->user_block_count -
	68	written_block_count(sbi);
	69	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
	70	}
	71
b59d0bae	72	static inline long increase_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
7bc09003	73	{
b59d0bae	74	if (wait == gc_th->no_gc_sleep_time)
6cb968d9 JK	75	return wait;
6cb968d9 JK	76
b59d0bae NJ	77	wait += gc_th->min_sleep_time;
	78	if (wait > gc_th->max_sleep_time)
	79	wait = gc_th->max_sleep_time;
7bc09003 JK	80	return wait;
	81	}
	82
b59d0bae	83	static inline long decrease_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
7bc09003	84	{
b59d0bae NJ	85	if (wait == gc_th->no_gc_sleep_time)
b59d0bae NJ	86	wait = gc_th->max_sleep_time;
6cb968d9	87
b59d0bae NJ	88	wait -= gc_th->min_sleep_time;
	89	if (wait <= gc_th->min_sleep_time)
	90	wait = gc_th->min_sleep_time;
7bc09003 JK	91	return wait;
	92	}
	93
	94	static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
	95	{
	96	block_t invalid_user_blocks = sbi->user_block_count -
	97	written_block_count(sbi);
	98	/*
e1c42045	99	* Background GC is triggered with the following conditions.
7bc09003 JK	100	* 1. There are a number of invalid blocks.
	101	* 2. There is not enough free space.
	102	*/
	103	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
	104	free_user_blocks(sbi) < limit_free_user_blocks(sbi))
	105	return true;
	106	return false;
	107	}
	108
	109	static inline int is_idle(struct f2fs_sb_info *sbi)
	110	{
	111	struct block_device *bdev = sbi->sb->s_bdev;
	112	struct request_queue *q = bdev_get_queue(bdev);
	113	struct request_list *rl = &q->root_rl;
	114	return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
	115	}