From: Ingo Molnar <mingo@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
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@n>
Subject: Re: Arches that don't support PREEMPT
Date: Wed, 20 Sep 2023 09:32:38 +0200 [thread overview]
Message-ID: <ZQqgFpA6l1eK1KKV@gmail.com> (raw)
In-Reply-To: <20230919143816.1741760a@gandalf.local.home>
* Steven Rostedt <rostedt@goodmis.org> wrote:
> On Tue, 19 Sep 2023 20:31:50 +0200
> Thomas Gleixner <tglx@linutronix.de> wrote:
>
> > The removal of cond_resched() might cause latencies, but then I doubt
> > that these museus pieces are used for real work :)
>
> 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.
That's not a good idea IMO, it's an invitation for accelerated rate bitrot
turning cond_resched() meaningless very quickly.
We should remove cond_resched() - but probably not as the first step. They
are conceptually independent of NEED_RESCHED_LAZY and we don't *have to*
remove them straight away.
By removing cond_resched() separately there's an easily bisectable point to
blame for any longer latencies on legacy platforms, should any of them
still be used with recent kernels.
Thanks,
Ingo
next prev parent reply other threads:[~2023-09-20 7:32 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87edj64rj1.fsf@oracle.com>
[not found] ` <CAHk-=wi0bXpgULVVLc2AdJcta-fvQP7yyFQ_JtaoHUiPrqf--A@mail.gmail.com>
[not found] ` <87zg1u1h5t.fsf@oracle.com>
[not found] ` <CAHk-=whMkp68vNxVn1H3qe_P7n=X2sWPL9kvW22dsvMFH8FcQQ@mail.gmail.com>
[not found] ` <20230911150410.GC9098@noisy.programming.kicks-ass.net>
[not found] ` <87h6o01w1a.fsf@oracle.com>
[not found] ` <20230912082606.GB35261@noisy.programming.kicks-ass.net>
[not found] ` <87cyyfxd4k.ffs@tglx>
[not found] ` <CAHk-=whnwC01m_1f-gaM1xbvvwzwTiKitrWniA-ChZv+bM03dg@mail.gmail.com>
[not found] ` <87led2wdj0.ffs@tglx>
2023-09-19 13:00 ` Arches that don't support PREEMPT Matthew Wilcox
2023-09-19 13:34 ` Geert Uytterhoeven
2023-09-19 13:37 ` John Paul Adrian Glaubitz
2023-09-19 13:42 ` Peter Zijlstra
2023-09-19 13:48 ` John Paul Adrian Glaubitz
2023-09-19 14:16 ` Peter Zijlstra
2023-09-19 14:24 ` John Paul Adrian Glaubitz
2023-09-19 14:32 ` Matthew Wilcox
2023-09-19 15:31 ` Steven Rostedt
2023-09-20 14:38 ` Anton Ivanov
2023-09-21 12:20 ` Arnd Bergmann
2023-09-19 14:17 ` Thomas Gleixner
2023-09-19 14:50 ` H. Peter Anvin
2023-09-19 14:57 ` Matt Turner
2023-09-19 17:09 ` Ulrich Teichert
2023-09-19 17:25 ` Linus Torvalds
2023-09-19 17:58 ` John Paul Adrian Glaubitz
2023-09-19 18:31 ` Thomas Gleixner
2023-09-19 18:38 ` Steven Rostedt
2023-09-19 18:52 ` Linus Torvalds
2023-09-19 19:53 ` Thomas Gleixner
2023-09-20 7:32 ` Ingo Molnar [this message]
2023-09-20 7:29 ` Ingo Molnar
2023-09-20 8:26 ` Thomas Gleixner
2023-09-20 10:37 ` David Laight
2023-09-19 14:21 ` Anton Ivanov
2023-09-19 15:17 ` Thomas Gleixner
2023-09-19 15:21 ` Anton Ivanov
2023-09-19 16:22 ` Richard Weinberger
2023-09-19 16:41 ` Anton Ivanov
2023-09-19 17:33 ` Thomas Gleixner
2023-10-06 14:51 ` Geert Uytterhoeven
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