vitalif
/
e2fsprogs
mirror of https://github.com/vitalif/e2fsprogs
1
0
Fork 0
Code Issues Releases Wiki Activity

libext2fs: move a modulo operation out of a hot loop. 

Filesystem shrinking in particular is a heavy user of this loop in
ext2fs_new_inode(). This change makes resize2fs use 24% less CPU time
for shrinking a 100G filesystem.

Signed-off-by: Sami Liedes <sami.liedes@iki.fi>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
bitmap-optimize
Sami Liedes 2012-03-22 19:42:38 -04:00 committed by Theodore Ts'o
parent 010dc7b90d
commit 75556776d3
1 changed files with 9 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
lib/ext2fs/alloc.c
View File

@ -109,6 +109,7 @@ errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
ext2_ino_t dir_group = 0;
ext2_ino_t i;
ext2_ino_t start_inode;
ext2_ino_t ino_in_group;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
@ -126,17 +127,22 @@ errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
if (start_inode > fs->super->s_inodes_count)
return EXT2_ET_INODE_ALLOC_FAIL;
i = start_inode;
ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super);
do {
if (((i - 1) % EXT2_INODES_PER_GROUP(fs->super)) == 0)
if (ino_in_group == 0)
check_inode_uninit(fs, map, (i - 1) /
EXT2_INODES_PER_GROUP(fs->super));
if (!ext2fs_fast_test_inode_bitmap2(map, i))
break;
i++;
if (i > fs->super->s_inodes_count)
if (++ino_in_group == EXT2_INODES_PER_GROUP(fs->super))
ino_in_group = 0;
if (++i > fs->super->s_inodes_count) {
i = EXT2_FIRST_INODE(fs->super);
ino_in_group = ((i - 1) %
EXT2_INODES_PER_GROUP(fs->super));
}
} while (i != start_inode);
if (ext2fs_test_inode_bitmap2(map, i))