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From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
Cc:     Jaegeuk Kim <jaegeuk@kernel.org>
Subject: [PATCH] f2fs: do not issue small discard commands during checkpoint
Date:   Tue, 13 Jun 2023 13:39:47 -0700
Message-ID: <20230613203947.2745943-1-jaegeuk@kernel.org>
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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@kernel.org>
---
 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