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Commit e81c93cf authored by Changman Lee's avatar Changman Lee Committed by Jaegeuk Kim
Browse files

f2fs: improve searching speed of __next_free_blkoff 



To find a zero bit using the result of OR operation between ckpt_valid_map
and cur_valid_map is more fast than find a zero bit in each bitmap.

Signed-off-by: default avatarChangman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: adjust changed function name]
Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent 9a7f143a

fs/f2fs/segment.c

+12 −7
Original line number Diff line number Diff line
@@ -607,13 +607,18 @@ static void __next_free_blkoff(struct f2fs_sb_info *sbi, 
			struct curseg_info *seg, block_t start)

{

	struct seg_entry *se = get_seg_entry(sbi, seg->segno);

	block_t ofs;

	for (ofs = start; ofs < sbi->blocks_per_seg; ofs++) {

		if (!f2fs_test_bit(ofs, se->ckpt_valid_map)

			&& !f2fs_test_bit(ofs, se->cur_valid_map))

			break;

	}

	seg->next_blkoff = ofs;

	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);

	unsigned long target_map[entries];

	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;

	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;

	int i, pos;



	for (i = 0; i < entries; i++)

		target_map[i] = ckpt_map[i] | cur_map[i];



	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);



	seg->next_blkoff = pos;

}



/*