Commit d98af5f4 authored by Daeho Jeong's avatar Daeho Jeong Committed by Jaegeuk Kim
Browse files

f2fs: introduce gc_urgent_mid mode 



We need a mid level of gc urgent mode to do GC forcibly in a period
of given gc_urgent_sleep_time, but not like using greedy GC approach
and switching to SSR mode such as gc urgent high mode. This can be
used for more aggressive periodic storage clean up.

Signed-off-by: default avatarDaeho Jeong <daehojeong@google.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent d284af43

Documentation/ABI/testing/sysfs-fs-f2fs

+11 −6
Original line number Diff line number Diff line
@@ -297,11 +297,16 @@ Description: Shows current reserved blocks in system, it may be temporarily 
What:		/sys/fs/f2fs/<disk>/gc_urgent

Date:		August 2017

Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>

Description:	Do background GC aggressively when set. When gc_urgent = 1,

		background thread starts to do GC by given gc_urgent_sleep_time

		interval. When gc_urgent = 2, F2FS will lower the bar of

		checking idle in order to process outstanding discard commands

		and GC a little bit aggressively. It is set to 0 by default.

Description:	Do background GC aggressively when set. Set to 0 by default.

		gc urgent high(1): does GC forcibly in a period of given

		gc_urgent_sleep_time and ignores I/O idling check. uses greedy

		GC approach and turns SSR mode on.

		gc urgent low(2): lowers the bar of checking I/O idling in

		order to process outstanding discard commands and GC a

		little bit aggressively. uses cost benefit GC approach.

		gc urgent mid(3): does GC forcibly in a period of given

		gc_urgent_sleep_time and executes a mid level of I/O idling check.

		uses cost benefit GC approach.



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

Date:		August 2017
@@ -532,7 +537,7 @@ Date: July 2021 
Contact:	"Daeho Jeong" <daehojeong@google.com>

Description:	Show how many segments have been reclaimed by GC during a specific

		GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy,

		3: GC idle AT, 4: GC urgent high, 5: GC urgent low)

		3: GC idle AT, 4: GC urgent high, 5: GC urgent low 6: GC urgent mid)

		You can re-initialize this value to "0".



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

fs/f2fs/debug.c

+3 −1
Original line number Diff line number Diff line
@@ -476,12 +476,14 @@ static int stat_show(struct seq_file *s, void *v) 
				si->node_segs, si->bg_node_segs);

		seq_printf(s, "  - Reclaimed segs : Normal (%d), Idle CB (%d), "

				"Idle Greedy (%d), Idle AT (%d), "

				"Urgent High (%d), Urgent Low (%d)\n",

				"Urgent High (%d), Urgent Mid (%d), "

				"Urgent Low (%d)\n",

				si->sbi->gc_reclaimed_segs[GC_NORMAL],

				si->sbi->gc_reclaimed_segs[GC_IDLE_CB],

				si->sbi->gc_reclaimed_segs[GC_IDLE_GREEDY],

				si->sbi->gc_reclaimed_segs[GC_IDLE_AT],

				si->sbi->gc_reclaimed_segs[GC_URGENT_HIGH],

				si->sbi->gc_reclaimed_segs[GC_URGENT_MID],

				si->sbi->gc_reclaimed_segs[GC_URGENT_LOW]);

		seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,

				si->bg_data_blks + si->bg_node_blks);

fs/f2fs/f2fs.h

+4 −0
Original line number Diff line number Diff line
@@ -1313,6 +1313,7 @@ enum { 
	GC_IDLE_AT,

	GC_URGENT_HIGH,

	GC_URGENT_LOW,

	GC_URGENT_MID,

	MAX_GC_MODE,

};
@@ -2784,6 +2785,9 @@ static inline bool is_idle(struct f2fs_sb_info *sbi, int type) 
	if (is_inflight_io(sbi, type))

		return false;



	if (sbi->gc_mode == GC_URGENT_MID)

		return true;



	if (sbi->gc_mode == GC_URGENT_LOW &&

			(type == DISCARD_TIME || type == GC_TIME))

		return true;

fs/f2fs/gc.c

+3 −0
Original line number Diff line number Diff line
@@ -103,7 +103,10 @@ static int gc_thread_func(void *data) 
				sbi->gc_urgent_high_remaining--;

			}

			spin_unlock(&sbi->gc_urgent_high_lock);

		}



		if (sbi->gc_mode == GC_URGENT_HIGH ||

				sbi->gc_mode == GC_URGENT_MID) {

			wait_ms = gc_th->urgent_sleep_time;

			f2fs_down_write(&sbi->gc_lock);

			goto do_gc;

fs/f2fs/sysfs.c

+7 −0
Original line number Diff line number Diff line
@@ -468,6 +468,13 @@ static ssize_t __sbi_store(struct f2fs_attr *a, 
			}

		} else if (t == 2) {

			sbi->gc_mode = GC_URGENT_LOW;

		} else if (t == 3) {

			sbi->gc_mode = GC_URGENT_MID;

			if (sbi->gc_thread) {

				sbi->gc_thread->gc_wake = 1;

				wake_up_interruptible_all(

					&sbi->gc_thread->gc_wait_queue_head);

			}

		} else {

			return -EINVAL;

		}