Subject: Re: minor tweak to ffs_blkpref
To: Jason Thorpe <thorpej@shagadelic.org>
From: Darrin B.Jewell <dbj@netbsd.org>
List: tech-kern
Date: 06/08/2005 14:26:05
Jason Thorpe <thorpej@shagadelic.org> writes:

> On Jun 6, 2005, at 10:53 AM, Darrin B.Jewell wrote:
> 
> > The following patch starts the search for free blocks immediately
> > after the administration data in each cylinder group.  This results in
> > better contiguous layout and the small allocation region now will
> > only get used once the filesystem starts to get full.
> >
> > Does anyone see any downside?
> 
> Seems like a great idea.  Presumably that little chunk of space can
> still be used if there's no where else to store data?
> 
> -- thorpej

Yes, the mapsearch routine starts at the block returned by blkpref and
then proceeds forward linearly and will wrap around to the start of
the cylinder group.  This just affects where it starts the search
within each cylinder group when it begins a new run.

Darrin