On Wed, Mar 27, 2002 at 03:00:57PM +0000, Tony Gale wrote:
> I mean, how the hell did IBM get the jump on SGI with kernel
> integration? Someone missed a trick there.
If you look at JFS compared to XFS you will see two things:
a) outside fs/jfs only configuration/documentation is touched,
there are _no_ core kernel changes.
b) JFS uses the generic kernel filesystem code wherever possible
But this does not only have advantages:
- in 2.4 JFS requires two memory allocations for each new inode,
bot just one like ext2/ext3/xfs/etc
- JFS can't support features implemented in the disk format but not in
the main kernel. Examples are EAs/ACLs.
- sometimes the core kernel really should be changed. An example
is the missing export of block_flushpage in pre-2.4.18 kernels
(or 2.5) - JFS works around this in a way I absoloutly don't like.
I think XFS could try hard to archive the first item, even if it
loses some functionaly that needs to be pulled in through extra patches,
but given the current SGI policy/development model I don't think b)
is / will be a goal. It's up to Al and Linus to decide whether b) is
important or not, but I strongly doubt they will take an XFS patch with
all the mainline invasion the current version has.
Christoph
--
Of course it doesn't work. We've performed a software upgrade.
|