Subject: Re: Adding -nomtime to the kernel
To: Alan Barrett <apb@cequrux.com>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: tech-kern
Date: 09/17/2007 09:10:04
On Mon, 17 Sep 2007 11:58:03 +0200
Alan Barrett <apb@cequrux.com> wrote:

> On Sat, 15 Sep 2007, Darren Reed wrote:
> > Having done that, I'm wondering if it makes sense for NetBSD
> > to support -nomtime as well.
> 
> I have no objection to that, but I would use it very seldom or
> never.  I don't even like using noatime.

Agreed, on all points...
> 
> What I really want is something to help keep my laptop disk spun down
> as much as possible, while not losing the atime and mtime updates.
> Perhaps a mode in which atime and mtime updates get buffered up
> somehow, and get written to disk after a delay, or when the list of
> outstanding updates gets full, or when the file system is explicitly
> synced or unmounted.
> 
This is what Linux does, but in a more general fashion.  When on
battery, it waits a lot longer before flushing the buffer cache, but
when the disk is spun up, it flushes out a lot more.


		--Steve Bellovin, http://www.cs.columbia.edu/~smb