From: David Laight <David.Laight@ACULAB.COM>
To: 'Linus Torvalds' <torvalds@linux-foundation.org>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
Matthew Wilcox <willy@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ankur Arora <ankur.a.arora@oracle.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"x86@kernel.org" <x86@kernel.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"luto@kernel.org" <luto@kernel.org>,
"bp@alien8.de" <bp@alien8.de>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"hpa@zytor.com" <hpa@zytor.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"juri.lelli@redhat.com" <juri.lelli@redhat.com>,
"vincent.guittot@linaro.org" <vincent.guittot@linaro.org>,
"mgorman@suse.de" <mgorman@suse.de>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"jon.grimm@amd.com" <jon>
Subject: RE: Arches that don't support PREEMPT
Date: Wed, 20 Sep 2023 10:37:42 +0000 [thread overview]
Message-ID: <c3d5937c27824f7f879012cdeb876a14@AcuMS.aculab.com> (raw)
In-Reply-To: <CAHk-=wgUimqtF7PqFfRw4Ju5H1KYkp6+8F=hBz7amGQ8GaGKkA@mail.gmail.com>
From: Linus Torvalds
> Sent: 19 September 2023 18:25
>
> On Tue, 19 Sept 2023 at 06:48, John Paul Adrian Glaubitz
> <glaubitz@physik.fu-berlin.de> wrote:
> >
> > As Geert poined out, I'm not seeing anything particular problematic with the
> > architectures lacking CONFIG_PREEMPT at the moment. This seems to be more
> > something about organizing KConfig files.
>
> It can definitely be problematic.
>
> Not the Kconfig file part, and not the preempt count part itself.
>
> But the fact that it has never been used and tested means that there
> might be tons of "this architecture code knows it's not preemptible,
> because this architecture doesn't support preemption".
Do distos even build x86 kernels with PREEMPT_FULL?
I know I've had issues with massive latencies caused graphics driver
forcing write-backs of all the framebuffer memory.
(I think it is a failed attempt to fix a temporary display corruption.)
OTOH SMP support and CONFIG_RT will test most of the code.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2023-09-20 10:37 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
2023-09-20 7:29 ` Ingo Molnar
2023-09-20 8:26 ` Thomas Gleixner
2023-09-20 10:37 ` David Laight [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c3d5937c27824f7f879012cdeb876a14@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=akpm@linux-foundation.org \
--cc=ankur.a.arora@oracle.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=glaubitz@physik.fu-berlin.de \
--cc=hpa@zytor.com \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=vincent.guittot@linaro.org \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).