[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 MAX_VICTIM_SEARCH	20

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;
};

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

/*
 * 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 condition.
	 * 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 */
	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;
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;
7bc09003 JK	33	};
	34
	35	struct inode_entry {
	36	struct list_head list;
	37	struct inode *inode;
	38	};
	39
0a8165d7	40	/*
7bc09003 JK	41	* inline functions
	42	*/
	43	static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
	44	{
	45	if (free_segments(sbi) < overprovision_segments(sbi))
	46	return 0;
	47	else
	48	return (free_segments(sbi) - overprovision_segments(sbi))
	49	<< sbi->log_blocks_per_seg;
	50	}
	51
	52	static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
	53	{
	54	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
	55	}
	56
	57	static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
	58	{
	59	block_t reclaimable_user_blocks = sbi->user_block_count -
	60	written_block_count(sbi);
	61	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
	62	}
	63
b59d0bae	64	static inline long increase_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
7bc09003	65	{
b59d0bae	66	if (wait == gc_th->no_gc_sleep_time)
6cb968d9 JK	67	return wait;
6cb968d9 JK	68
b59d0bae NJ	69	wait += gc_th->min_sleep_time;
	70	if (wait > gc_th->max_sleep_time)
	71	wait = gc_th->max_sleep_time;
7bc09003 JK	72	return wait;
	73	}
	74
b59d0bae	75	static inline long decrease_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
7bc09003	76	{
b59d0bae NJ	77	if (wait == gc_th->no_gc_sleep_time)
b59d0bae NJ	78	wait = gc_th->max_sleep_time;
6cb968d9	79
b59d0bae NJ	80	wait -= gc_th->min_sleep_time;
	81	if (wait <= gc_th->min_sleep_time)
	82	wait = gc_th->min_sleep_time;
7bc09003 JK	83	return wait;
	84	}
	85
	86	static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
	87	{
	88	block_t invalid_user_blocks = sbi->user_block_count -
	89	written_block_count(sbi);
	90	/*
	91	* Background GC is triggered with the following condition.
	92	* 1. There are a number of invalid blocks.
	93	* 2. There is not enough free space.
	94	*/
	95	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
	96	free_user_blocks(sbi) < limit_free_user_blocks(sbi))
	97	return true;
	98	return false;
	99	}
	100
	101	static inline int is_idle(struct f2fs_sb_info *sbi)
	102	{
	103	struct block_device *bdev = sbi->sb->s_bdev;
	104	struct request_queue *q = bdev_get_queue(bdev);
	105	struct request_list *rl = &q->root_rl;
	106	return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
	107	}