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From:   Rob Herring <robh+dt@kernel.org>
Date:   Thu, 6 Jul 2023 11:40:05 -0600
Message-ID: <CAL_JsqK7MHR09U5h01=Gf1ZLeDVCgZdN-W1hQRH3AX+E94_uUg@mail.gmail.com>
Subject: Re: [PATCH v4 00/21] Add Qualcomm Minidump kernel driver related support
To:     Trilok Soni <quic_tsoni@quicinc.com>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Mukesh Ojha <quic_mojha@quicinc.com>,
        Greg KH <gregkh@linuxfoundation.org>, corbet@lwn.net,
        agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        keescook@chromium.org, tony.luck@intel.com, gpiccoli@igalia.com,
        mathieu.poirier@linaro.org, catalin.marinas@arm.com,
        will@kernel.org, linus.walleij@linaro.org,
        andy.shevchenko@gmail.com, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org, linux-hardening@vger.kernel.org,
        linux-remoteproc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org,
        Alex Elder <elder@linaro.org>
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On Mon, Jul 3, 2023 at 3:06=E2=80=AFPM Trilok Soni <quic_tsoni@quicinc.com>=
 wrote:
>
> On 7/2/2023 1:29 AM, Krzysztof Kozlowski wrote:
> > On 30/06/2023 18:04, Mukesh Ojha wrote:
> >>>
> >>>> We don't add layers when they are not needed, and never when there i=
s no
> >>>> actual user.  If you need the extra "complexity" later, then add it
> >>>> later when it is needed as who knows when that will ever be.
> >>>>
> >>>> Please redo this series based on that, thanks.
> >>>
> >>> My bigger issue with this whole series is what would this all look
> >>> like if every SoC vendor upstreamed their own custom dumping
> >>> mechanism. That would be a mess. (I have similar opinions on the
> >>> $soc-vendor hypervisors.)
> >
> > Mukesh,
> >
> > LPC CFP is still open. There will be also Android and Kernel Debugging
> > LPC microconference tracks. Coming with a unified solution could be a
> > great topic for LPC. Solutions targeting only one user are quite often
> > frowned upon.
>
> LPC is far out and in November. Can we not have others speak up if they
> have the similar solution now? We can expand this to linux-kernel and
> ask for the other SOC vendors to chime in. I am sure that we may have
> existing solutions which came in for the one user first like Intel RDT
> if I remember. I am sure ARM MPAM usecase was present at that time but
> Intel RDT based solution which was x86 specific but accepted.

RDT predated MPAM. resctrl is the kernel feature, and it supports
Intel and AMD which are not identical. resctrl is being (extensively)
refactored to add in MPAM support.

You are not the first here like Intel RDT, so I fail to see the
parallel with minidump. We have an existing logging to persistent
storage mechanism which is pstore. You should integrate into that
rather than grafting something on to the side or underneath.

Rob