Journaling UFS with gjournal.

[Mike Jakubik]

Pawel Jakub Dawidek wrote:
> Copying one large file:
> UFS:		8s
> UFS+SU:		8s
> gjournal(1):	16s
> gjournal(2):	14s
>
> Copying eight large files in parallel:
> UFS:		120s
> UFS+SU:		120s
> gjournal(1):	184s
> gjournal(2):	165s
>
> Untaring eight src.tgz in parallel:
> UFS:		791s
> UFS+SU:		650s
> gjournal(1):	333s
> gjournal(2):	309s
>
> Reading. grep -r on two src/ directories in parallel:
> UFS:		84s
> UFS+SU:		138s
> gjournal(1):	102s
> gjournal(2):	89s
>   

Not to sound ungrateful for the work, which i am, this is great! But the 
performance impact seems rather large to me. Does the presence of 
journaling mean that we could perhaps mount the filesystems async? Does 
it eliminate the need for softupdates?