linux-kernel - Re: [RFC PATCH 00/86] Make the kernel preemptible

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]

Date:   Wed, 8 Nov 2023 13:16:41 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Ankur Arora <ankur.a.arora@...cle.com>
Cc:     linux-kernel@...r.kernel.org, tglx@...utronix.de,
        torvalds@...ux-foundation.org, paulmck@...nel.org,
        linux-mm@...ck.org, x86@...nel.org, akpm@...ux-foundation.org,
        luto@...nel.org, bp@...en8.de, dave.hansen@...ux.intel.com,
        hpa@...or.com, mingo@...hat.com, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, willy@...radead.org, mgorman@...e.de,
        jon.grimm@....com, bharata@....com, raghavendra.kt@....com,
        boris.ostrovsky@...cle.com, konrad.wilk@...cle.com,
        jgross@...e.com, andrew.cooper3@...rix.com, mingo@...nel.org,
        bristot@...nel.org, mathieu.desnoyers@...icios.com,
        geert@...ux-m68k.org, glaubitz@...sik.fu-berlin.de,
        anton.ivanov@...bridgegreys.com, mattst88@...il.com,
        krypton@...ich-teichert.org, rostedt@...dmis.org,
        David.Laight@...lab.com, richard@....at, mjguzik@...il.com
Subject: Re: [RFC PATCH 00/86] Make the kernel preemptible

On Wed, Nov 08, 2023 at 12:14:15PM +0100, Peter Zijlstra wrote:

> I would really suggest you start with transforming VOLUNTARY into the
> LAZY thing, keep it as simple and narrow as possible.

Possibly make it worse first, add LAZY as a fourth option, then show it
makes VOLUNTARY redundant, kill that.

> Once you've got that done, then you can try and argue that NONE makes no
> sense and try and take it out.

This also pushes out having to deal with the !PREEMPT archs until the
very last moment.

And once you're here, cond_resched() should be an obvious no-op function
and you can go delete them.

Anyway, as said, smaller steps more better. Nobody likes 86 patches in
their inbox in the morning (or at any time really).