linux-kernel - [PATCH] f2fs: remove unnecessary segment bitmap updates

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Date:	Mon, 28 Oct 2013 14:06:47 +0900
From:	Jaegeuk Kim <jaegeuk.kim@...sung.com>
To:	unlisted-recipients:; (no To-header on input)
Cc:	Changman Lee <cm224.lee@...sung.com>,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net,
	Jaegeuk Kim <jaegeuk.kim@...sung.com>
Subject: [PATCH] f2fs: remove unnecessary segment bitmap updates

From: Changman Lee <cm224.lee@...sung.com>

From: Changman Lee <cm224.lee@...sung.com>

Only one dirty type is set in __locate_dirty_segment and we can know
dirty type of segment. So we don't need to check other dirty types.

Signed-off-by: Changman Lee <cm224.lee@...sung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@...sung.com>
---
 fs/f2fs/segment.c | 31 ++++++++-----------------------
 1 file changed, 8 insertions(+), 23 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 487af61..8f92c18 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -58,20 +58,10 @@ static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
 
 	if (dirty_type == DIRTY) {
 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
-		enum dirty_type t = DIRTY_HOT_DATA;
+		enum dirty_type t = sentry->type;
 
-		dirty_type = sentry->type;
-
-		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
-			dirty_i->nr_dirty[dirty_type]++;
-
-		/* Only one bitmap should be set */
-		for (; t <= DIRTY_COLD_NODE; t++) {
-			if (t == dirty_type)
-				continue;
-			if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
-				dirty_i->nr_dirty[t]--;
-		}
+		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
+			dirty_i->nr_dirty[t]++;
 	}
 }
 
@@ -84,16 +74,11 @@ static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
 		dirty_i->nr_dirty[dirty_type]--;
 
 	if (dirty_type == DIRTY) {
-		enum dirty_type t = DIRTY_HOT_DATA;
-
-		/* clear its dirty bitmap */
-		for (; t <= DIRTY_COLD_NODE; t++) {
-			if (test_and_clear_bit(segno,
-						dirty_i->dirty_segmap[t])) {
-				dirty_i->nr_dirty[t]--;
-				break;
-			}
-		}
+		struct seg_entry *sentry = get_seg_entry(sbi, segno);
+		enum dirty_type t = sentry->type;
+
+		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
+			dirty_i->nr_dirty[t]--;
 
 		if (get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
 			clear_bit(GET_SECNO(sbi, segno),
-- 
1.8.4.474.g128a96c

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