Subject: Re: mp->mnt_vnodelist change
To: Reinoud Zandijk <>
From: Thor Lancelot Simon <>
List: tech-kern
Date: 10/18/2006 17:36:15
On Wed, Oct 18, 2006 at 11:32:19PM +0200, Reinoud Zandijk wrote:
> Dear Thor and Manuel,
> On Wed, Oct 18, 2006 at 03:02:44PM -0400, Thor Lancelot Simon wrote:
> > > I think this can affect normal disks as well; e.g. hardware RAID controllers
> > > which have heuristics to detect sequencial writes.
> > 
> > I'm trying to understand this: are you saying that every time we walk the
> > vnode list to flush, we end up writing blocks in reverse order?
> Normal data blocks most likely are done fine but the vnode list is ordered 
> in the reverse order as accessed/created. Thats due to the head insertion 
> of new vnodes loaded/created so earlier vnodes get later and later on the 
> tree.

Does this mean that when the syncfs syncer walks the vnode list to flush
pending writes for files, the files too are scheduled in what is likely
to be the reverse order of their physical location on the disk?