2023-05-12 04:29:32

by Yonggil Song

Subject: [PATCH v1] f2fs: Fix over-estimating free section during FG GC

There was a bug that finishing FG GC unconditionally because free sections
are over-estimated after checkpoint in FG GC.
This patch initializes sec_freed by every checkpoint in FG GC.

Signed-off-by: Yonggil Song <[email protected]>
---
fs/f2fs/gc.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index d455140322a8..51d7e8d29bf1 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1797,7 +1797,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
{
int gc_type = gc_control->init_gc_type;
unsigned int segno = gc_control->victim_segno;
- int sec_freed = 0, seg_freed = 0, total_freed = 0;
+ int sec_freed = 0, seg_freed = 0, total_freed = 0, total_sec_freed = 0;
int ret = 0;
struct cp_control cpc;
struct gc_inode_list gc_list = {
@@ -1842,6 +1842,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
ret = f2fs_write_checkpoint(sbi, &cpc);
if (ret)
goto stop;
+ /* Reset due to checkpoint */
+ sec_freed = 0;
}
}

@@ -1866,15 +1868,17 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
gc_control->should_migrate_blocks);
total_freed += seg_freed;

- if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
+ if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno)) {
sec_freed++;
+ total_sec_freed++;
+ }

if (gc_type == FG_GC) {
sbi->cur_victim_sec = NULL_SEGNO;

if (has_enough_free_secs(sbi, sec_freed, 0)) {
if (!gc_control->no_bg_gc &&
- sec_freed < gc_control->nr_free_secs)
+ total_sec_freed < gc_control->nr_free_secs)
goto go_gc_more;
goto stop;
}
@@ -1901,6 +1905,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
ret = f2fs_write_checkpoint(sbi, &cpc);
if (ret)
goto stop;
+ /* Reset due to checkpoint */
+ sec_freed = 0;
}
go_gc_more:
segno = NULL_SEGNO;
@@ -1913,7 +1919,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
if (gc_type == FG_GC)
f2fs_unpin_all_sections(sbi, true);

- trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
+ trace_f2fs_gc_end(sbi->sb, ret, total_freed, total_sec_freed,
get_pages(sbi, F2FS_DIRTY_NODES),
get_pages(sbi, F2FS_DIRTY_DENTS),
get_pages(sbi, F2FS_DIRTY_IMETA),
@@ -1927,7 +1933,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
put_gc_inode(&gc_list);

if (gc_control->err_gc_skipped && !ret)
- ret = sec_freed ? 0 : -EAGAIN;
+ ret = total_sec_freed ? 0 : -EAGAIN;
return ret;
}

--
2.34.1

2023-05-17 03:17:58

by Chao Yu

Subject: Re: [PATCH v1] f2fs: Fix over-estimating free section during FG GC

On 2023/5/12 12:16, Yonggil Song wrote:
> There was a bug that finishing FG GC unconditionally because free sections
> are over-estimated after checkpoint in FG GC.
> This patch initializes sec_freed by every checkpoint in FG GC.
>
> Signed-off-by: Yonggil Song <[email protected]>

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

Thanks,

2023-05-18 01:57:47

by patchwork-bot+f2fs

Subject: Re: [f2fs-dev] [PATCH v1] f2fs: Fix over-estimating free section during FG GC

Hello:

This patch was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <[email protected]>:

On Fri, 12 May 2023 13:16:10 +0900 you wrote:
> There was a bug that finishing FG GC unconditionally because free sections
> are over-estimated after checkpoint in FG GC.
> This patch initializes sec_freed by every checkpoint in FG GC.
>
> Signed-off-by: Yonggil Song <[email protected]>
> ---
> fs/f2fs/gc.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)

Here is the summary with links:
- [f2fs-dev,v1] f2fs: Fix over-estimating free section during FG GC
https://git.kernel.org/jaegeuk/f2fs/c/62c85994b958

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html