Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35;
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>
Cc:     John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Matthew Wilcox <willy@infradead.org>,
        Ankur Arora <ankur.a.arora@oracle.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
        akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de,
        dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com,
        juri.lelli@redhat.com, vincent.guittot@linaro.org, mgorman@suse.de,
        jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com,
        boris.ostrovsky@oracle.com, konrad.wilk@oracle.com,
        jgross@suse.com, andrew.cooper3@citrix.com,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        linux-m68k@lists.linux-m68k.org,
        Richard Weinberger <richard@nod.at>,
        Anton Ivanov <anton.ivanov@cambridgegreys.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        linux-um@lists.infradead.org, Brian Cain <bcain@quicinc.com>,
        linux-hexagon@vger.kernel.org,
        Richard Henderson <richard.henderson@linaro.org>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
        Matt Turner <mattst88@gmail.com>, linux-alpha@vger.kernel.org
Subject: Re: Arches that don't support PREEMPT
In-Reply-To: <CAHk-=wizB-G40OxALNnz3-uNxuEAPf95H9hubAPeG2r2mrhwHA@mail.gmail.com>
References: <87zg1u1h5t.fsf@oracle.com>
 <CAHk-=whMkp68vNxVn1H3qe_P7n=X2sWPL9kvW22dsvMFH8FcQQ@mail.gmail.com>
 <20230911150410.GC9098@noisy.programming.kicks-ass.net>
 <87h6o01w1a.fsf@oracle.com>
 <20230912082606.GB35261@noisy.programming.kicks-ass.net>
 <87cyyfxd4k.ffs@tglx>
 <CAHk-=whnwC01m_1f-gaM1xbvvwzwTiKitrWniA-ChZv+bM03dg@mail.gmail.com>
 <87led2wdj0.ffs@tglx> <ZQmbhoQIINs8rLHp@casper.infradead.org>
 <0e69f7df80dc5878071deb0d80938138d19de1d1.camel@physik.fu-berlin.de>
 <20230919134218.GA39281@noisy.programming.kicks-ass.net>
 <a6c84803274116ec827cd4bdd4e72a8d0c304c27.camel@physik.fu-berlin.de>
 <CAHk-=wgUimqtF7PqFfRw4Ju5H1KYkp6+8F=hBz7amGQ8GaGKkA@mail.gmail.com>
 <87pm2eui95.ffs@tglx> <20230919143816.1741760a@gandalf.local.home>
 <CAHk-=wizB-G40OxALNnz3-uNxuEAPf95H9hubAPeG2r2mrhwHA@mail.gmail.com>
Date:   Tue, 19 Sep 2023 21:53:07 +0200
Message-ID: <87jzsmueho.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Tue, Sep 19 2023 at 11:52, Linus Torvalds wrote:
> On Tue, 19 Sept 2023 at 11:37, Steven Rostedt <rostedt@goodmis.org> wrote:
>>
>> We could simply leave the cond_resched() around but defined as nops for
>> everything but the "nostalgia club" to keep them from having any regressions.
>
> I doubt the nostalgia club cares about some latencies (that are
> usually only noticeable under extreme loads anyway).
>
> And if they do, maybe that would make somebody sit down and look into
> doing it right.
>
> So I think keeping it around would actually be both useless and
> counter-productive.

Amen to that.