Re: [PATCH 1/3] sysfs directory scaling: rbtree for dirent name lookups

Benjamin LaHaise [off-list ref] writes:

Use an rbtree in sysfs_dirent to speed up file lookup times

Systems with large numbers (tens of thousands and more) of network 
interfaces stress the sysfs code in ways that make the linear search for 
a name match take far too long.  Avoid this by using an rbtree.

Please take a look at the cleanups_scaling branch at:
kernel.org:/pub/scm/linux/kernel/git/ebiederm/linux-2.6.32-rc5-sysfs-enhancements

I haven't spent a lot of time on it but it is possible to get everything
except the rbtree without increasing the size of sysfs_dirent.  Also we
don't need the both the rbtree and a linked list.

In particular see:
commit 50623bbb82da3bd1d596b9173a91ed1b5aa168b8
Author: Eric W. Biederman [off-list ref]
Date:   Sat Oct 31 04:11:18 2009 -0700

    sysfs: Sort sysfs directories by name hash.
    
    This is a step in preparation for introducing a more efficient
    data structure than a linked list for sysfs entries.  By ordering
    by name hash instead of by inode sysfs_lookup can be speeded
    up as well as allowing restarting after seekdir.
    
    Signed-off-by: Eric W. Biederman [off-list ref]

Meanwhile back to pushing the most important ones for real.

Eric