From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gu Zheng Subject: [PATCH 3/4] f2fs: use find_next_bit_le rather than test_bit_le in, find_in_block Date: Tue, 24 Jun 2014 18:20:41 +0800 Message-ID: <53A950F9.907@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: f2fs , fsdevel , =?UTF-8?B?7J207LC966eM?= To: Jaegeuk Kim Return-path: Received: from cn.fujitsu.com ([59.151.112.132]:36550 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751713AbaFXKcE (ORCPT ); Tue, 24 Jun 2014 06:32:04 -0400 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Use find_next_bit_le rather than test_bit_le to improve search speed lightly. Signed-off-by: Gu Zheng --- fs/f2fs/dir.c | 43 +++++++++++++++++++++---------------------- 1 files changed, 21 insertions(+), 22 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 3edd561..ba510fb 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -93,42 +93,41 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, const char *name, size_t namelen, int *max_slots, f2fs_hash_t namehash, struct page **res_page) { - struct f2fs_dir_entry *de; - unsigned long bit_pos = 0; + unsigned long bit_pos = 0, bit_start = 0; struct f2fs_dentry_block *dentry_blk = kmap(dentry_page); const void *dentry_bits = &dentry_blk->dentry_bitmap; - int max_len = 0; - while (bit_pos < NR_DENTRY_IN_BLOCK) { - if (!test_bit_le(bit_pos, dentry_bits)) { - if (bit_pos == 0) - max_len = 1; - else if (!test_bit_le(bit_pos - 1, dentry_bits)) - max_len++; - bit_pos++; - continue; + while (bit_start < NR_DENTRY_IN_BLOCK) { + struct f2fs_dir_entry *de; + int max_len = 0; + + bit_pos = find_next_bit_le(dentry_bits, + NR_DENTRY_IN_BLOCK, bit_start); + + max_len = bit_pos - bit_start; + if (max_len > *max_slots) { + *max_slots = max_len; + max_len = 0; } + + if (bit_pos >= NR_DENTRY_IN_BLOCK) + break; + de = &dentry_blk->dentry[bit_pos]; if (early_match_name(name, namelen, namehash, de)) { if (!memcmp(dentry_blk->filename[bit_pos], name, namelen)) { *res_page = dentry_page; - goto found; + return de; } } - if (max_len > *max_slots) { - *max_slots = max_len; - max_len = 0; - } - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + + bit_start = bit_pos + + GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); } - de = NULL; kunmap(dentry_page); -found: - if (max_len > *max_slots) - *max_slots = max_len; - return de; + return NULL; } static struct f2fs_dir_entry *find_in_level(struct inode *dir, -- 1.7.7