[Gllug] Thoughts on the breadth of Free Software

Daniel P. Berrange dan at berrange.com
Mon Sep 18 12:22:43 UTC 2006


On Mon, Sep 18, 2006 at 12:44:14PM +0100, Christian Smith wrote:
> salsaman uttered:
> 
> >Here's another suggestion:
> >
> >the C functions "open" and "fopen" are notoriously slow, because lists of 
> >files within a directory are maintained as a linked list within libc. This 
> >list must be traversed entry by entry until the required file can be 
> >located on the disk.
> >
> >It seems to me there is much room for improvement here.
> 
> Not necessarily true.
> 
> FS such as XFS, JFS and ReiserFS have BTree directories. Ext3 and UFS can 
> have optional hashed directory entries.

Directory b-tree hashing has been on by default in ext3 for quite a while 
now (it was in RHEL-4 / Fedora Core 2+  - ~2.6.9 kernel) & existing 
filesystems can be toggled using a simple 'tune2fs -O dir_index'.

Regards,
Dan.
-- 
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