linux/fs/f2fs/gc.h
Jaegeuk Kim d0239e1bf5 f2fs: detect idle time depending on user behavior
This patch adds last time that user requested filesystem operations.
This information is used to detect whether system is idle or not later.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-01-11 15:56:37 -08:00

103 lines
2.8 KiB
C

/*
* 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 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 void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
long *wait)
{
if (*wait == gc_th->no_gc_sleep_time)
return;
*wait += gc_th->min_sleep_time;
if (*wait > gc_th->max_sleep_time)
*wait = gc_th->max_sleep_time;
}
static inline void 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;
}
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;
}