[PATCHSET 2.6.22-rc2-mm1] sysfs: reduce memory footprint of sysfs_dirent

[Tejun Heo <htejun@gmail.com>]

Hello, all.

This patchset reduces the size of sysfs_dirent to 88 byte from 136 on
64bit and to 52 from 76 on 32bit.  Combined with forthcoming
reclaimable sysfs directories, this will make sysfs much more scalable
on very large machines and very small machines.

This patchset contains the following three patches.

#01: move-s_active-functions-to-fs-sysfs-dir-c, prep for #02
#02: slim-down-sysfs_dirent-s_active
#03: use-signly-linked-list-for-sysfs_dirent-tree

I'm pretty sure #02 is a good idea but #03 is debatable.  The code
doesn't look much uglier after the conversion tho.  Inputs welcome.

This patchset is on top of

  2.6.22-rc2-mm1
+ [1] sysfs-assorted-fixes patchset

 fs/sysfs/dir.c   |  272 ++++++++++++++++++++++++++++++++++++++++++++-----------
 fs/sysfs/inode.c |   12 +-
 fs/sysfs/mount.c |    3 
 fs/sysfs/sysfs.h |  111 ++--------------------
 4 files changed, 237 insertions(+), 161 deletions(-)

Thanks.

--
tejun

[1] http://thread.gmane.org/gmane.linux.kernel/535372