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f2fs: check all ones or zeros bitmap with bitops for better mount performance

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Previously, check_block_count check valid_map with bit data type in common
scenario that sit has all ones or zeros bitmap, it makes low mount performance.
So let's check the special bitmap with integer data type instead of the bit one.

v1-->v2:
 o use find_next_{zero_}bit_le for better performance and readable as Jaegeuk
   suggested.
 o use neat logogram in comment as Gu Zheng suggested.
 o search continuous ones or zeros for better performance when checking mixed
   bitmap.

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Shu Tan <shu.tan@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This commit is contained in:
Chao Yu 2013-10-29 14:50:40 +08:00 committed by Jaegeuk Kim
parent 9a47938b22
commit 44c60bf2b9
1 changed files with 15 additions and 4 deletions
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19
fs/f2fs/segment.h
View file

@ -547,8 +547,9 @@ static inline void check_block_count(struct f2fs_sb_info *sbi,
{
struct f2fs_sm_info *sm_info = SM_I(sbi);
unsigned int end_segno = sm_info->segment_count - 1;
bool is_valid = test_bit_le(0, raw_sit->valid_map) ? true : false;
int valid_blocks = 0;
int i;
int cur_pos = 0, next_pos;
/* check segment usage */
BUG_ON(GET_SIT_VBLOCKS(raw_sit) > sbi->blocks_per_seg);
@ -557,9 +558,19 @@ static inline void check_block_count(struct f2fs_sb_info *sbi,
BUG_ON(segno > end_segno);
/* check bitmap with valid block count */
for (i = 0; i < sbi->blocks_per_seg; i++)
if (f2fs_test_bit(i, raw_sit->valid_map))
valid_blocks++;
do {
if (is_valid) {
next_pos = find_next_zero_bit_le(&raw_sit->valid_map,
sbi->blocks_per_seg,
cur_pos);
valid_blocks += next_pos - cur_pos;
} else
next_pos = find_next_bit_le(&raw_sit->valid_map,
sbi->blocks_per_seg,
cur_pos);
cur_pos = next_pos;
is_valid = !is_valid;
} while (cur_pos < sbi->blocks_per_seg);
BUG_ON(GET_SIT_VBLOCKS(raw_sit) != valid_blocks);
}
#else