Received-SPF: pass (google.com: domain of linux-kernel+bounces-54727-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Date: Tue, 6 Feb 2024 10:59:05 +0000
From: Mark Brown <broonie@kernel.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Bo Liu <liubo03@inspur.com>, lee@kernel.org, wens@csie.org,
	marek.vasut+renesas@gmail.com, support.opensource@diasemi.com,
	neil.armstrong@linaro.org, ckeepax@opensource.cirrus.com,
	rf@opensource.cirrus.com, mazziesaccount@gmail.com,
	mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com,
	linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	linux-amlogic@lists.infradead.org, patches@opensource.cirrus.com,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 00/18] mfd: convert to use maple tree register cache
Message-ID: <ZcIQ+f3F/hSU1Jcx@finisterre.sirena.org.uk>
References: <20240206071314.8721-1-liubo03@inspur.com>
 <CAMuHMdU7fYCsNT9ditqJ-saUsRm9J2zLh=-q-zmExhBRJeE8NQ@mail.gmail.com>
 <ZcIE/RMTq34TgpQt@finisterre.sirena.org.uk>
 <CAMuHMdVj1bS9s69ASrd5xULc8oELoBbnb8HEX9MEmA43853_EQ@mail.gmail.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="wohqWBqzA9LyPZP8"
Content-Disposition: inline
In-Reply-To: <CAMuHMdVj1bS9s69ASrd5xULc8oELoBbnb8HEX9MEmA43853_EQ@mail.gmail.com>


--wohqWBqzA9LyPZP8
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Tue, Feb 06, 2024 at 11:14:11AM +0100, Geert Uytterhoeven wrote:
> On Tue, Feb 6, 2024 at 11:09=E2=80=AFAM Mark Brown <broonie@kernel.org> w=
rote:

> > There is a very small niche for devices where cache syncs are a
> > particularly important part of the workload where rbtree's choices might
> > give better performance, especially on systems with low end CPUs.

> The REGCACHE_* value is specified by the device, not by the CPU?

The device is going to dominate here, the main thing is how much of the
workload consists of syncs.

> While some of these MFD devices are on-SoC, and thus there is some
> relation between device and CPU, several others (e.g. PMICs) are
> external, and thus might be present on systems with a variety of CPU
> performance.

> Perhaps the value should depend on some CPU heuristic instead?

No.

--wohqWBqzA9LyPZP8
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmXCEPgACgkQJNaLcl1U
h9CLEQf/Q8Y34eZ58gNTCjgBWHllS9BWTNNoJRfggd2UXR/TK6Wux1Oco73AD+sp
j/x/FfZT9XT7iXbarZ87ZUfIEOS0Av7GhvLufUzoxtgfwbGkm+8sR96avkCzf8sX
WpZ5sICL8fs2NykKkJt76AWsgWaBOYnRgyZrIZ+0a1w+ZUiE5UYEb6TQ7IZZtKrE
EehYa/mJg3yWROqkiRtnEvouDAmIAgVH7rM2Vfj9G79uLyG4fsvvsuOEjQ5KMGMU
IQAfWU0Vik+XfvR3VhaP11Bd3wjt8noEbyksgDXNSHwDDNH1zytr6GrQJGJkkVh0
JB5leaIP9fDnAmofgyqoOqG6uUokNQ==
=UNpd
-----END PGP SIGNATURE-----

--wohqWBqzA9LyPZP8--