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From:   Pavel Tatashin <pasha.tatashin@soleen.com>
Date:   Tue, 9 Jul 2019 09:07:54 -0400
Message-ID: <CA+CK2bA40wQvX=KieE5Qg2Ny5ZyiDAAjAb9W7Phu2Ou_9r6bOA@mail.gmail.com>
Subject: Re: [v1 0/5] allow to reserve memory for normal kexec kernel
To:     James Morse <james.morse@arm.com>
Cc:     Bhupesh Sharma <bhsharma@redhat.com>,
        James Morris <jmorris@namei.org>,
        Sasha Levin <sashal@kernel.org>,
        Eric Biederman <ebiederm@xmission.com>,
        kexec mailing list <kexec@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Catalin Marinas <catalin.marinas@arm.com>, will@kernel.org,
        Linux Doc Mailing List <linux-doc@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
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> > Enabling MMU and D-Cache for relocation  would essentially require the
> > same changes in kernel. Could you please share exactly why these were
> > not accepted upstream into kexec-tools?
>
> Because '--no-checks' is a much simpler alternative.
>
> More of the discussion:
> https://lore.kernel.org/linux-arm-kernel/5599813d-f83c-d154-287a-c131c48292ca@arm.com/
>
> While you can make purgatory a fully-fledged operating system, it doesn't really need to
> do anything on arm64. Errata-workarounds alone are a reason not do start down this path.

Thank you James. I will summaries the information gathered from the
yesterday's/today's discussion and add it to the cover letter together
with ARM64 tag. I think, the patch series makes sense for ARM64 only,
unless there are other platforms that disable caching/MMU during
relocation.

Thank you,
Pasha


>
>
> Thanks,
>
> James