Commit b59d0bae authored by Namjae Jeon's avatar Namjae Jeon Committed by Jaegeuk Kim
Browse files

f2fs: add sysfs support for controlling the gc_thread 



Add sysfs entries to control the timing parameters for
f2fs gc thread.

Various Sysfs options introduced are:
gc_min_sleep_time: Min Sleep time for GC in ms
gc_max_sleep_time: Max Sleep time for GC in ms
gc_no_gc_sleep_time: Default Sleep time for GC in ms

Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarPankaj Kumar <pankaj.km@samsung.com>
Reviewed-by: default avatarGu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: fix an umount bug and some minor changes]
Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent f0c5e565

Documentation/ABI/testing/sysfs-fs-f2fs

0 → 100644
+20 −0
Original line number Diff line number Diff line 
What:		/sys/fs/f2fs/<disk>/gc_max_sleep_time

Date:		July 2013

Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>

Description:

		 Controls the maximun sleep time for gc_thread. Time

		 is in milliseconds.



What:		/sys/fs/f2fs/<disk>/gc_min_sleep_time

Date:		July 2013

Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>

Description:

		 Controls the minimum sleep time for gc_thread. Time

		 is in milliseconds.



What:		/sys/fs/f2fs/<disk>/gc_no_gc_sleep_time

Date:		July 2013

Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>

Description:

		 Controls the default sleep time for gc_thread. Time

		 is in milliseconds.

Documentation/filesystems/f2fs.txt

+26 −0
Original line number Diff line number Diff line
@@ -132,6 +132,32 @@ f2fs. Each file shows the whole f2fs information. 
 - average SIT information about whole segments

 - current memory footprint consumed by f2fs.



================================================================================

SYSFS ENTRIES

================================================================================



Information about mounted f2f2 file systems can be found in

/sys/fs/f2fs.  Each mounted filesystem will have a directory in

/sys/fs/f2fs based on its device name (i.e., /sys/fs/f2fs/sda).

The files in each per-device directory are shown in table below.



Files in /sys/fs/f2fs/<devname>

(see also Documentation/ABI/testing/sysfs-fs-f2fs)

..............................................................................

 File                         Content



 gc_max_sleep_time            This tuning parameter controls the maximum sleep

                              time for the garbage collection thread. Time is

                              in milliseconds.



 gc_min_sleep_time            This tuning parameter controls the minimum sleep

                              time for the garbage collection thread. Time is

                              in milliseconds.



 gc_no_gc_sleep_time          This tuning parameter controls the default sleep

                              time for the garbage collection thread. Time is

                              in milliseconds.



================================================================================

USAGE

================================================================================

fs/f2fs/f2fs.h

+4 −0
Original line number Diff line number Diff line
@@ -430,6 +430,10 @@ struct f2fs_sb_info { 
#endif

	unsigned int last_victim[2];		/* last victim segment # */

	spinlock_t stat_lock;			/* lock for stat operations */



	/* For sysfs suppport */

	struct kobject s_kobj;

	struct completion s_kobj_unregister;

};



/*

fs/f2fs/gc.c

+11 −6
Original line number Diff line number Diff line
@@ -29,10 +29,11 @@ static struct kmem_cache *winode_slab; 
static int gc_thread_func(void *data)

{

	struct f2fs_sb_info *sbi = data;

	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;

	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;

	long wait_ms;



	wait_ms = GC_THREAD_MIN_SLEEP_TIME;

	wait_ms = gc_th->min_sleep_time;



	do {

		if (try_to_freeze())
@@ -45,7 +46,7 @@ static int gc_thread_func(void *data) 
			break;



		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {

			wait_ms = GC_THREAD_MAX_SLEEP_TIME;

			wait_ms = increase_sleep_time(gc_th, wait_ms);

			continue;

		}
@@ -66,15 +67,15 @@ static int gc_thread_func(void *data) 
			continue;



		if (!is_idle(sbi)) {

			wait_ms = increase_sleep_time(wait_ms);

			wait_ms = increase_sleep_time(gc_th, wait_ms);

			mutex_unlock(&sbi->gc_mutex);

			continue;

		}



		if (has_enough_invalid_blocks(sbi))

			wait_ms = decrease_sleep_time(wait_ms);

			wait_ms = decrease_sleep_time(gc_th, wait_ms);

		else

			wait_ms = increase_sleep_time(wait_ms);

			wait_ms = increase_sleep_time(gc_th, wait_ms);



#ifdef CONFIG_F2FS_STAT_FS

		sbi->bg_gc++;
@@ -82,7 +83,7 @@ static int gc_thread_func(void *data) 


		/* if return value is not zero, no victim was selected */

		if (f2fs_gc(sbi))

			wait_ms = GC_THREAD_NOGC_SLEEP_TIME;

			wait_ms = gc_th->no_gc_sleep_time;

	} while (!kthread_should_stop());

	return 0;

}
@@ -101,6 +102,10 @@ int start_gc_thread(struct f2fs_sb_info *sbi) 
		goto out;

	}



	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;

	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;

	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;



	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,

fs/f2fs/gc.h

+19 −14
Original line number Diff line number Diff line
@@ -13,9 +13,9 @@ 
						 * whether IO subsystem is idle

						 * or not

						 */

#define GC_THREAD_MIN_SLEEP_TIME	30000	/* milliseconds */

#define GC_THREAD_MAX_SLEEP_TIME	60000

#define GC_THREAD_NOGC_SLEEP_TIME	300000	/* wait 5 min */

#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 */
@@ -25,6 +25,11 @@ 
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 {
@@ -56,25 +61,25 @@ static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi) 
	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;

}



static inline long increase_sleep_time(long wait)

static inline long increase_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)

{

	if (wait == GC_THREAD_NOGC_SLEEP_TIME)

	if (wait == gc_th->no_gc_sleep_time)

		return wait;



	wait += GC_THREAD_MIN_SLEEP_TIME;

	if (wait > GC_THREAD_MAX_SLEEP_TIME)

		wait = GC_THREAD_MAX_SLEEP_TIME;

	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(long wait)

static inline long decrease_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)

{

	if (wait == GC_THREAD_NOGC_SLEEP_TIME)

		wait = GC_THREAD_MAX_SLEEP_TIME;

	if (wait == gc_th->no_gc_sleep_time)

		wait = gc_th->max_sleep_time;



	wait -= GC_THREAD_MIN_SLEEP_TIME;

	if (wait <= GC_THREAD_MIN_SLEEP_TIME)

		wait = GC_THREAD_MIN_SLEEP_TIME;

	wait -= gc_th->min_sleep_time;

	if (wait <= gc_th->min_sleep_time)

		wait = gc_th->min_sleep_time;

	return wait;

}

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