From e81c93cf8c7bd413898798cf8c67f18b1fef3360 Mon Sep 17 00:00:00 2001 From: Changman Lee Date: Fri, 15 Nov 2013 13:21:16 +0900 Subject: [PATCH] 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: Changman Lee [Jaegeuk Kim: adjust changed function name] Signed-off-by: Jaegeuk Kim --- fs/f2fs/segment.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index aa1d30d..67f1e5b 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -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; } /* -- 2.7.4