f2fs: add sysfs entries to select the gc policy

Add sysfs entry gc_idle to control the gc policy. Where
gc_idle = 1 corresponds to selecting a cost benefit approach,
while gc_idle = 2 corresponds to selecting a greedy approach
to garbage collection. The selection is mutually exclusive one
approach will work at any point. If gc_idle = 0, then this
option is disabled.

Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: change the select_gc_type() flow slightly]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This commit is contained in:
Namjae Jeon 2013-08-04 23:10:15 +09:00 коммит произвёл Jaegeuk Kim
Родитель b59d0bae6c
Коммит d2dc095f42
5 изменённых файлов: 30 добавлений и 3 удалений

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@ -18,3 +18,9 @@ Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
Description:
Controls the default sleep time for gc_thread. Time
is in milliseconds.
What: /sys/fs/f2fs/<disk>/gc_idle
Date: July 2013
Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
Description:
Controls the victim selection policy for garbage collection.

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@ -158,6 +158,12 @@ Files in /sys/fs/f2fs/<devname>
time for the garbage collection thread. Time is
in milliseconds.
gc_idle This parameter controls the selection of victim
policy for garbage collection. Setting gc_idle = 0
(default) will disable this option. Setting
gc_idle = 1 will select the Cost Benefit approach
& setting gc_idle = 2 will select the greedy aproach.
================================================================================
USAGE
================================================================================

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@ -106,6 +106,8 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
gc_th->gc_idle = 0;
sbi->gc_thread = gc_th;
init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
@ -130,9 +132,17 @@ void stop_gc_thread(struct f2fs_sb_info *sbi)
sbi->gc_thread = NULL;
}
static int select_gc_type(int gc_type)
static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
{
return (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
if (gc_th && gc_th->gc_idle) {
if (gc_th->gc_idle == 1)
gc_mode = GC_CB;
else if (gc_th->gc_idle == 2)
gc_mode = GC_GREEDY;
}
return gc_mode;
}
static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
@ -145,7 +155,7 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
p->dirty_segmap = dirty_i->dirty_segmap[type];
p->ofs_unit = 1;
} else {
p->gc_mode = select_gc_type(gc_type);
p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
p->ofs_unit = sbi->segs_per_sec;
}

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@ -30,6 +30,9 @@ struct f2fs_gc_kthread {
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 {

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@ -148,12 +148,14 @@ static struct f2fs_attr f2fs_attr_##_name = { \
F2FS_RW_ATTR(gc_min_sleep_time, min_sleep_time);
F2FS_RW_ATTR(gc_max_sleep_time, max_sleep_time);
F2FS_RW_ATTR(gc_no_gc_sleep_time, no_gc_sleep_time);
F2FS_RW_ATTR(gc_idle, gc_idle);
#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
static struct attribute *f2fs_attrs[] = {
ATTR_LIST(gc_min_sleep_time),
ATTR_LIST(gc_max_sleep_time),
ATTR_LIST(gc_no_gc_sleep_time),
ATTR_LIST(gc_idle),
NULL,
};