linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Andreas Schwab <schwab@suse.de>
Cc: Yury Norov <yury.norov@gmail.com>,
	linux-kernel@vger.kernel.org,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	Dmitry Vyukov <dvyukov@google.com>,
	Valentin Schneider <vschneid@redhat.com>,
	Sander Vanheule <sander@svanheule.net>,
	Alexey Klimov <klimov.linux@gmail.com>,
	Eric Biggers <ebiggers@google.com>,
	linux-riscv <linux-riscv@lists.infradead.org>
Subject: Re: [PATCH v2 5/5] lib/cpumask: add FORCE_NR_CPUS config option
Date: Tue, 18 Oct 2022 15:50:31 +0200	[thread overview]
Message-ID: <CAMuHMdVeHPR_JH0dJ+WSddjd8_hax70JRzd4pqHLNvgbh+-znw@mail.gmail.com> (raw)
In-Reply-To: <mvmlepdb66h.fsf@suse.de>

Hi Andreas,

On Tue, Oct 18, 2022 at 3:41 PM Andreas Schwab <schwab@suse.de> wrote:
> On Okt 18 2022, Geert Uytterhoeven wrote:
> > Moreover, this cannot be used on all systems.  E.g. on Icicle Kit with
> > Microchip PolarFire SoC, CONFIG_NR_CPUS needs to be larger than 4,
> > as the system has actually 5 CPU cores (1xE51 and 4xU54), but Linux
> > runs only on 4 of them.  So you cannot use FORCE_NR_CPUS=y.
>
> But does Linux acually see the E51 core?  On the Hifive boards it is
> disabled in the device tree, and the cpu probing just skips it,
> effectively resulting in only four cpus.

The E51 is indeed disabled in DT.
The CPU parts of arch/riscv/boot/dts/sifive/fu540-c000.dtsi and
arch/riscv/boot/dts/microchip/mpfs.dtsi arre very similar.
Do you get 4 CPUs on Hifive with CONFIG_NR_CPUS=4?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

  reply	other threads:[~2022-10-18 13:50 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-05 23:08 [PATCH v2 0/5] cpumask: cleanup nr_cpu_ids vs nr_cpumask_bits mess Yury Norov
2022-09-05 23:08 ` [PATCH v2 1/5] smp: don't declare nr_cpu_ids if NR_CPUS == 1 Yury Norov
2022-09-06  8:53   ` Peter Zijlstra
2022-09-06 14:06     ` Yury Norov
2022-09-06 14:36       ` Peter Zijlstra
2022-09-06 15:01         ` Andy Shevchenko
2022-09-06 17:53           ` Peter Zijlstra
2022-09-06 15:07         ` Yury Norov
2022-09-07  8:02         ` David Laight
2022-09-05 23:08 ` [PATCH v2 2/5] smp: add set_nr_cpu_ids() Yury Norov
2022-09-05 23:08 ` [PATCH v2 3/5] lib/cpumask: delete misleading comment Yury Norov
2022-09-05 23:08 ` [PATCH v2 4/5] lib/cpumask: deprecate nr_cpumask_bits Yury Norov
2022-09-05 23:08 ` [PATCH v2 5/5] lib/cpumask: add FORCE_NR_CPUS config option Yury Norov
2022-10-18  8:21   ` Geert Uytterhoeven
2022-10-18 13:15     ` Geert Uytterhoeven
2022-10-18 13:41       ` Andreas Schwab
2022-10-18 13:50         ` Geert Uytterhoeven [this message]
2022-10-18 14:35           ` Yury Norov
2022-10-18 14:44             ` Andy Shevchenko
2022-10-18 14:59               ` Yury Norov
2022-10-18 15:15                 ` Geert Uytterhoeven
2022-10-18 16:16                   ` Yury Norov
2022-10-19  6:58                     ` Geert Uytterhoeven
2022-09-06  8:55 ` [PATCH v2 0/5] cpumask: cleanup nr_cpu_ids vs nr_cpumask_bits mess Peter Zijlstra
2022-09-06 12:06   ` Valentin Schneider
2022-09-06 14:38     ` Peter Zijlstra
2022-09-06 15:45       ` Valentin Schneider
2022-09-06 16:26         ` Yury Norov
2022-09-06 14:48     ` Yury Norov
2022-09-06 14:35   ` Yury Norov
2022-09-15 14:45 ` Yury Norov

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=CAMuHMdVeHPR_JH0dJ+WSddjd8_hax70JRzd4pqHLNvgbh+-znw@mail.gmail.com \
    --to=geert@linux-m68k.org \
    --cc=akpm@linux-foundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=dvyukov@google.com \
    --cc=ebiggers@google.com \
    --cc=klimov.linux@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=linux@rasmusvillemoes.dk \
    --cc=paulmck@kernel.org \
    --cc=peterz@infradead.org \
    --cc=sander@svanheule.net \
    --cc=schwab@suse.de \
    --cc=sfr@canb.auug.org.au \
    --cc=tglx@linutronix.de \
    --cc=vbabka@suse.cz \
    --cc=vschneid@redhat.com \
    --cc=yury.norov@gmail.com \
    /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).