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| author | Tejun Heo <htejun@gmail.com> | 2007-06-14 03:45:18 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-11 16:09:07 -0700 |
| commit | 0c73f18b7d95de8a007039337063a770b5fc8e7a (patch) | |
| tree | cf3b6f274139b170136219918dd679f2397e69f6 /fs/sysfs/inode.c | |
| parent | 8619f979898397582e366877fd5feeba7560d70c (diff) | |
| download | lwn-0c73f18b7d95de8a007039337063a770b5fc8e7a.tar.gz lwn-0c73f18b7d95de8a007039337063a770b5fc8e7a.zip | |
sysfs: use singly-linked list for sysfs_dirent tree
Make sysfs_dirent use singly linked list for its tree structure.
sysfs_link_sibling() and sysfs_unlink_sibling() functions are added to
handle simpler cases. It adds some complexity and cpu cycle overhead
but reduced memory footprint is worthwhile on big machines.
This change reduces the sizeof sysfs_dirent from 104 to 88 on 64bit
and from 60 to 52 on 32bit.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs/sysfs/inode.c')
| -rw-r--r-- | fs/sysfs/inode.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 3eab9c46a71b..732fd7f371e0 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -284,8 +284,8 @@ void sysfs_drop_dentry(struct sysfs_dirent *sd) int sysfs_hash_and_remove(struct dentry * dir, const char * name) { - struct sysfs_dirent * sd; - struct sysfs_dirent * parent_sd; + struct sysfs_dirent **pos, *sd; + struct sysfs_dirent *parent_sd = dir->d_fsdata; int found = 0; if (!dir) @@ -295,13 +295,15 @@ int sysfs_hash_and_remove(struct dentry * dir, const char * name) /* no inode means this hasn't been made visible yet */ return -ENOENT; - parent_sd = dir->d_fsdata; mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); - list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { + for (pos = &parent_sd->s_children; *pos; pos = &(*pos)->s_sibling) { + sd = *pos; + if (!sd->s_type) continue; if (!strcmp(sd->s_name, name)) { - list_del_init(&sd->s_sibling); + *pos = sd->s_sibling; + sd->s_sibling = NULL; found = 1; break; } |