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Date: Wed, 13 Mar 2024 18:28:31 -0400
From: Kent Overstreet <kent.overstreet@linux.dev>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>, linux-bcachefs@vger.kernel.org, 
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [GIT PULL] bcachefs updates for 6.9
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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@linux.dev> 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.