Re: vfs05.patch

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:On Wed, 29 Sep 2004, Matthew Dillon wrote:
:
:>
:>     But the grand result, when all is said and done, is going to be a big
:>     improvement in path lookup performance...
:
:Very briefly (25 words or less) could you clarify for me just how much this
:current work depends on what you've already done.  I.e. could this upcoming
:work be applied to FBSD 4.x as well as DFly?

    No, short of a major (~1000+ man-hour) development effort by the BSD
    folks I'm afraid its impossible.  The lead-up to this work is literally 
    several megabytes worth of patches that have gone in over the last year,
    all over the codebase, and all dependant on DragonFly's infrastructure.
    This part of the work is going to be another several megabytes worth of
    patches and as we get into the threading aspects of it it will depend
    even more heavily on DFly's infrastructure.

:Will these major changes involve userland also?  (Sounds to me like they may.)
:
:That is:  when I get kernel panics can I just reboot the old kernel and carry
:on -- or not?  IOW, the prospect of re-installing from scratch looms large?
:
:I don't necessarily object, but I'd better burn a recent install CD if that's
:the case.

    They do not involve userland, except inasmuch as they might change certain
    kernel structures and make things like 'ps' not work.  You can switch between
    old and new kernels.  I recommend keeping the userland associated with the
    old kernel.  Be careful of modules.  If you use any modules there are going
    to be divergance issues.  I think acpi.ko will remain safe, at least for now,
    but other modules will diverge.

					-Matt
					Matthew Dillon 
					<dillon@xxxxxxxxxxxxx>