[PATCH] f2fs: do not issue small discard commands during checkpoint

From: Jaegeuk Kim
Date: Tue Jun 13 2023 - 16:40:19 EST


If there're huge # of small discards, this will increase checkpoint latency
insanely. Let's issue small discards only by trim.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/segment.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 0c0c033c4bdd..ef46bb085385 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2178,7 +2178,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
}
mutex_unlock(&dirty_i->seglist_lock);

- if (!f2fs_block_unit_discard(sbi))
+ if (!f2fs_block_unit_discard(sbi) || !force)
goto wakeup;

/* send small discards */
@@ -2192,8 +2192,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
sbi->blocks_per_seg, cur_pos);
len = next_pos - cur_pos;

- if (f2fs_sb_has_blkzoned(sbi) ||
- (force && len < cpc->trim_minlen))
+ if (f2fs_sb_has_blkzoned(sbi) || len < cpc->trim_minlen)
goto skip;

f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos,
--
2.41.0.162.gfafddb0af9-goog