linux-kernel - Re: [PATCH 00/18] mfd: convert to use maple tree register cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZcIQ+f3F/hSU1Jcx@finisterre.sirena.org.uk>
Date: Tue, 6 Feb 2024 10:59:05 +0000
From: Mark Brown <broonie@...nel.org>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Bo Liu <liubo03@...pur.com>, lee@...nel.org, wens@...e.org,
	marek.vasut+renesas@...il.com, support.opensource@...semi.com,
	neil.armstrong@...aro.org, ckeepax@...nsource.cirrus.com,
	rf@...nsource.cirrus.com, mazziesaccount@...il.com,
	mcoquelin.stm32@...il.com, alexandre.torgue@...s.st.com,
	linux-kernel@...r.kernel.org, linux-renesas-soc@...r.kernel.org,
	linux-amlogic@...ts.infradead.org, patches@...nsource.cirrus.com,
	linux-stm32@...md-mailman.stormreply.com,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 00/18] mfd: convert to use maple tree register cache

On Tue, Feb 06, 2024 at 11:14:11AM +0100, Geert Uytterhoeven wrote:
> On Tue, Feb 6, 2024 at 11:09 AM Mark Brown <broonie@...nel.org> wrote:

> > 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.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)