Re: hundreds of mount --bind mountpoints?

From: Erik Mouw (J.A.K.Mouw@ITS.TUDelft.NL)
Date: Tue Apr 24 2001 - 15:45:59 EST

On Tue, Apr 24, 2001 at 12:47:38PM -0600, Andreas Dilger wrote:
> While I applaud your initiative, you made an unfortunate choice of
> filesystems to convert. The iso_inode_info is only 4*__u32, as is
> proc_inode_info. Given that we still need to keep a pointer to the
> external info structs, and the overhead of the slab cache itself
> (both CPU usage and memory overhead, however small), I don't think
> it is worthwhile to have isofs and procfs in separate slabs.

Well, I know a little bit about procfs because I'm currently
documenting it, so that's why I picked it first. After I got the idea,
isofs was quite easy.

In retrospect it would have been more effective to pick a filesystem
with a larger *_inode_info field, but then again: Al is right. Struct
inode is cluttered with *_inode_info fields, while we use anonymous
data entries in other parts of the kernel (like the data pointer in
struct proc_dir_entry, or the priv pointer in struct net_device).

There is another advantage: suppose you're hacking on a filesystem and
change it's *_fs_i.h header. With Al's proposal you only have to
recompile the filesystem you're hacking on, while you have to recompile
the complete kernel in the current situation.


J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031,  2600 GA Delft, The Netherlands
Phone: +31-15-2783635  Fax: +31-15-2781843  Email:
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Mon Apr 30 2001 - 21:00:12 EST