2022-03-16 14:14:43

by Daeho Jeong

[permalink] [raw]
Subject: [PATCH] f2fs: introduce gc_urgent_mid mode

From: Daeho Jeong <[email protected]>

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: Daeho Jeong <[email protected]>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 17 +++++++++++------
fs/f2fs/debug.c | 4 +++-
fs/f2fs/f2fs.h | 4 ++++
fs/f2fs/gc.c | 3 +++
fs/f2fs/sysfs.c | 7 +++++++
5 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 5a5f3c5445f6..9b583dd0298b 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -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" <[email protected]>
-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" <[email protected]>
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
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 6d26872c7364..fcdf253cd211 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -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);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index da729f53daa8..3016b6354a68 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -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;
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 2d53ef121e76..ea5b93b689cd 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -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;
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 47efcf233afd..fe29bcb70f46 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -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;
}
--
2.35.1.723.g4982287a31-goog


2022-03-17 06:27:56

by Chao Yu

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH] f2fs: introduce gc_urgent_mid mode

On 2022/3/16 12:14, Daeho Jeong wrote:
> From: Daeho Jeong <[email protected]>
>
> 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: Daeho Jeong <[email protected]>

Reviewed-by: Chao Yu <[email protected]>

Thanks,