RELENG_4 -> 5 -> 6: significant performance regression

[Kris Kennaway]

On Thu, Apr 27, 2006 at 03:47:37PM -0400, Mike Jakubik wrote:
> Bartosz Fabianowski wrote:
> >>You wrote that Giant is needed in 6.0 and now you write it has been
> >>removed.
> >
> >In 4.x, every UFS write requires the Giant lock. In 6.x, Giant is not 
> >normally required, making file system operations faster. When you 
> >enable QUOTA, you basically get back to the 4.x behavior where Giant 
> >is needed for each write. This is why in 6.x UFS will normally be 
> >faster but if you enable QUOTA, you lose the newly gained performance 
> >again.
> 
> Why isn't QUOTA mpsafe then?

Because code doesn't grow on trees.  There are uncommitted patches
though - perhaps you can test them and get back to the author with
your feedback.

Kris
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