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| author | Fan Li <fanofcode.li@samsung.com> | 2017-11-07 19:14:24 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-11-09 09:43:09 -0800 |
| commit | 974565744955b6154a93c85b77cb94026c85ff5a (patch) | |
| tree | fefdedfa4ff3872c5a10affb50ebcd47cba59927 /fs/f2fs | |
| parent | 74986213adaff2ceab81fc0bb29dbb80d05665b3 (diff) | |
| download | linux-974565744955b6154a93c85b77cb94026c85ff5a.tar.gz | |
f2fs: optimize the way of traversing free_nid_bitmap
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.li@samsung.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/node.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 97799bd503cc..be6fb809f519 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 @@ out: 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)); |