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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 25 Jan 2022 21:12:30 +0100
Message-ID: <CAMuHMdXJoREF7jZaYWrDUjJqKUSCd82qDVaMEo7VO38ok8J-AA@mail.gmail.com>
Subject: Re: [PATCH v3 6/6] RISC-V: Do not use cpumask data structure for
 hartid bitmap
To:     Atish Patra <atishp@rivosinc.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Anup Patel <anup@brainfault.org>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Atish Patra <atishp@atishpatra.org>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, Jisheng Zhang <jszhang@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Rob Herring <robh+dt@kernel.org>,
        Emil Renner Berthing <kernel@esmil.dk>
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Hi Atish,

On Thu, Jan 20, 2022 at 10:12 AM Atish Patra <atishp@rivosinc.com> wrote:
> Currently, SBI APIs accept a hartmask that is generated from struct
> cpumask. Cpumask data structure can hold upto NR_CPUs value. Thus, it
> is not the correct data structure for hartids as it can be higher
> than NR_CPUs for platforms with sparse or discontguous hartids.
>
> Remove all association between hartid mask and struct cpumask.
>
> Reviewed-by: Anup Patel <anup@brainfault.org> (For Linux RISC-V changes)
> Acked-by: Anup Patel <anup@brainfault.org> (For KVM RISC-V changes)
> Signed-off-by: Atish Patra <atishp@rivosinc.com>

Thanks for your patch, which is now commit 26fb751ca37846c9 ("RISC-V:
Do not use cpumask data structure for hartid bitmap") in v5.17-rc1.

I am having an issue with random userspace SEGVs on Starlight Beta
(which needs out-of-tree patches).  It doesn't always manifest
itself immediately, so it took a while to bisect, but I suspect the
above commit to be the culprit.

So far the Icicle looks unaffected.

Do you have a clue?
Thanks!

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