Re: [GIT PULL] bcachefs updates for 6.9

From: Kent Overstreet
Date: Wed Mar 13 2024 - 18:28:44 EST


On Wed, Mar 13, 2024 at 06:22:57PM -0400, Kent Overstreet wrote:
> On Wed, Mar 13, 2024 at 02:51:38PM -0700, Linus Torvalds wrote:
> > On Wed, 13 Mar 2024 at 14:34, Kent Overstreet <kent.overstreet@xxxxxxxxx> wrote:
> > >
> > > I liked your MAD suggestion, but the catch was that we need an
> > > exponentially weighted version,
> >
> > The code for the weighted version literally doesn't change.
>
> Well, no, and there's another problem I can't believe I missed until
> now. MAD is defined as median of the absolute deviations, not mean, and
> you can't compute a median incrementally.
>
> So MAD doesn't work here at all.

Sorry, you were talking about mean absolute deviation; that does work
here.