Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20220120090918.2646626-1-atishp@rivosinc.com> <20220120090918.2646626-7-atishp@rivosinc.com>
 <CAMuHMdXJoREF7jZaYWrDUjJqKUSCd82qDVaMEo7VO38ok8J-AA@mail.gmail.com>
In-Reply-To: <CAMuHMdXJoREF7jZaYWrDUjJqKUSCd82qDVaMEo7VO38ok8J-AA@mail.gmail.com>
From:   Atish Patra <atishp@atishpatra.org>
Date:   Tue, 25 Jan 2022 12:17:44 -0800
Message-ID: <CAOnJCULjqeL9Q27n=g19ALbOivzid6pc_gYv6JUF4iP=64kJ-Q@mail.gmail.com>
Subject: Re: [PATCH v3 6/6] RISC-V: Do not use cpumask data structure for
 hartid bitmap
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Atish Patra <atishp@rivosinc.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Anup Patel <anup@brainfault.org>,
        Albert Ou <aou@eecs.berkeley.edu>,
        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>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Jan 25, 2022 at 12:12 PM Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
>
> 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.
>

I have never seen one before during my testing. How frequently do you see them?
Does it happen while running anything or just idle user space results
in SEGVs randomly.

Do you have a trace that I can look into ?

> 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


-- 
Regards,
Atish