Re: [ck] Re: [PATCH] fcache: a remapping boot cache

["André Goddard Rosa" <andre.goddard@gmail.com>]

On 6/24/06, Jens Axboe <axboe@suse.de> wrote:
> On Sat, Jun 24 2006, James wrote:
> > Set this up on my laptop yesterday with some awesome results. I'm
> > using 2.6.17-ck1 which has v2.1.
> >
> > Heres some bootcharts, before, after, and a prime run.
> >
> > http://archlinux.org/~james/normal.png
> > http://archlinux.org/~james/fs-fcache.png
> > http://archlinux.org/~james/fs-fcache-prime.png
> >
> > Repeated boots show about the same 6 second improvement, 32 down to 26
> > seconds. Looking at the slowdowns in the fs-fcache run, most are due
> > to cpu load, waiting on network or, modprobe, and not disk access. X
> > now starts nearly instantaneously.
> >
> > As an experiment, I primed my cache right through to logging into my
> > desktop environment. It was so effective, that now when I login, the
> > GNOME splash screen only flickers onto the screen briefly, and the
> > panels appear almost instantly. This is a big improvment over without
> > fcache, where you'd see each component of GNOME being loaded on the
> > splash screen, nautilus, metacity, and the panels would take quite a
> > bit of time to render and load all their applets.
> >
> > Impressive work, I hope to see it broadened to other filesystems,
> > improved and merged to vanilla soon because it has clear improvements.
>
> Thanks for giving it a spin! I have plans to implement some improvements
> on monday that will speed it up even more, I hope I can talk you into
> retesting it then. Basically it make sure we always get full speed out
> of the drive by extending the 4kb reads with a sliding window cache.
> That will help both drive efficiency, and also speed up the cases where
> sub sequent boots differ just a little bit from the primed boot (often
> the case with parallel init scripts). It should win you a few seconds
> more in total, would be my guess.
>
> I hope to be able to extend it to xfs and reiser in the very near future
> as well, should not be hard to do.

Impressive good work, Jens!

Do you have any distribution in contact with you already?

Thank you so much, I look forward to test it on xfs.

Best regards,
-- 
[]s,
André Goddard