tree cf3b6f274139b170136219918dd679f2397e69f6
parent 8619f979898397582e366877fd5feeba7560d70c
author Tejun Heo <htejun@gmail.com> 1181760318 +0900
committer Greg Kroah-Hartman <gregkh@suse.de> 1184195347 -0700

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>