From: James Morse <james.morse@arm.com>
To: Pavel Tatashin <pasha.tatashin@soleen.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>
Subject: Re: [v1 0/5] allow to reserve memory for normal kexec kernel
Date: Wed, 10 Jul 2019 16:19:07 +0100 [thread overview]
Message-ID: <f9bea5bd-370a-47b5-8ad1-a30bd43d6cca@arm.com> (raw)
In-Reply-To: <CA+CK2bA40wQvX=KieE5Qg2Ny5ZyiDAAjAb9W7Phu2Ou_9r6bOA@mail.gmail.com>
Hi Pasha,
On 09/07/2019 14:07, Pavel Tatashin wrote:
>>> 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.
I'd prefer not to reserve additional memory for regular kexec just to avoid the relocation.
If the kernel's relocation work is so painful we can investigate doing it while the MMU is
enabled. If you can compare regular-kexec with kexec_file_load() you eliminate the
purgatory part of the work.
Thanks,
James
next prev parent reply other threads:[~2019-07-10 15:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-08 21:15 [v1 0/5] allow to reserve memory for normal kexec kernel Pavel Tatashin
2019-07-08 21:15 ` [v1 1/5] kexec: quiet down kexec reboot Pavel Tatashin
2019-07-08 21:15 ` [v1 2/5] kexec: add resource for normal kexec region Pavel Tatashin
2019-07-08 21:15 ` [v1 3/5] kexec: export common crashkernel/kexeckernel parser Pavel Tatashin
2019-07-08 21:15 ` [v1 4/5] kexec: use reserved memory for normal kexec reboot Pavel Tatashin
2019-07-08 21:15 ` [v1 5/5] arm64, kexec: reserve kexeckernel region Pavel Tatashin
2019-07-08 23:53 ` [v1 0/5] allow to reserve memory for normal kexec kernel Eric W. Biederman
2019-07-09 0:09 ` Pavel Tatashin
2019-07-09 10:18 ` James Morse
2019-07-09 10:36 ` Bhupesh Sharma
2019-07-09 10:55 ` Pavel Tatashin
2019-07-09 11:59 ` James Morse
2019-07-09 13:07 ` Pavel Tatashin
2019-07-10 15:19 ` James Morse [this message]
2019-07-10 15:56 ` Pavel Tatashin
2019-07-11 8:12 ` Vladimir Murzin
2019-07-11 12:26 ` Pavel Tatashin
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