Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Tue, 18 Oct 2022 15:50:31 +0200 | Subject | Re: [PATCH v2 5/5] lib/cpumask: add FORCE_NR_CPUS config option |
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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
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