>From 5199982d29ff291b181c25af63a22d6f2d6d3f7b Mon Sep 17 00:00:00 2001 From: Lokesh Nagappa Jaliminche Date: Sat, 26 Dec 2015 13:19:36 +0530 Subject: [PATCH] ext4: optimizing group serch for inode allocation Added a check at the start of group search loop to avoid looping unecessarily in case of empty group. This also allow group search to jump directly to "found_flex_bg" with "stats" and "group" already set, so there is no need to go through the extra steps of setting "best_desc" and "best_group" and then break out of the loop just to set "stats" and "group" again. Signed-off-by: Lokesh Nagappa Jaliminche --- fs/ext4/ialloc.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 1b8024d..16f94db 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -473,10 +473,14 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); if (S_ISDIR(mode) && - ((parent == d_inode(sb->s_root)) || - (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) { + ((parent == d_inode(sb->s_root)) || + (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) { + unsigned int inodes_per_flex_group; + unsigned long int clusters_per_flex_group; int best_ndir = inodes_per_group; int ret = -1; + inodes_per_flex_group = inodes_per_group * flex_size; + clusters_per_flex_group = sbi->s_clusters_per_group * flex_size; if (qstr) { hinfo.hash_version = DX_HASH_HALF_MD4; @@ -489,6 +493,10 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, for (i = 0; i < ngroups; i++) { g = (parent_group + i) % ngroups; get_orlov_stats(sb, g, flex_size, &stats); + /* the group can't get any better than empty */ + if (inodes_per_flex_group == stats.free_inodes && + clusters_per_flex_group == stats.free_clusters) + goto found_flex_bg; if (!stats.free_inodes) continue; if (stats.used_dirs >= best_ndir) -- 1.7.1