We call scan_free_nid_bits only when there isn't many
free nids left, it means that marked bits in free_nid_bitmap
are supposed to be few, use find_next_bit_le is more
efficient in such case.
According to my tests, use find_next_bit_le instead of
test_bit_le will cut down the traversal time to one
third of its original.
Signed-off-by: Fan li <fanofcode...@samsung.com>
---
fs/f2fs/node.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index fef5c68..d234c6e 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1955,6 +1955,7 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
struct f2fs_journal *journal = curseg->journal;
unsigned int i, idx;
+ nid_t nid;
down_read(&nm_i->nat_tree_lock);
@@ -1964,10 +1965,10 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
if (!nm_i->free_nid_count[i])
continue;
for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) {
- nid_t nid;
-
- if (!test_bit_le(idx, nm_i->free_nid_bitmap[i]))
- continue;
+ idx = find_next_bit_le(nm_i->free_nid_bitmap[i],
+ NAT_ENTRY_PER_BLOCK, idx);
+ if (idx >= NAT_ENTRY_PER_BLOCK)
+ break;
nid = i * NAT_ENTRY_PER_BLOCK + idx;
add_free_nid(sbi, nid, true);
@@ -1980,7 +1981,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
down_read(&curseg->journal_rwsem);
for (i = 0; i < nats_in_cursum(journal); i++) {
block_t addr;
- nid_t nid;
addr = le32_to_cpu(nat_in_journal(journal, i).block_addr);
nid = le32_to_cpu(nid_in_journal(journal, i));
--
2.7.4
