linux-kernel - Re: [PATCH 4/5] arm64: Verify CPU errata work arounds on hotplugged CPU

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Message-ID: <5710F653.5070301@arm.com>
Date:	Fri, 15 Apr 2016 15:10:27 +0100
From:	Suzuki K Poulose <Suzuki.Poulose@....com>
To:	Will Deacon <will.deacon@....com>, mark.rutland@....com
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	marc.zyngier@....com, catalin.marinas@....com,
	Vadim.Lomovtsev@...iumnetworks.com,
	Andre Przywara <andre.przywara@....com>
Subject: Re: [PATCH 4/5] arm64: Verify CPU errata work arounds on hotplugged
 CPU

On 14/04/16 18:49, Suzuki K Poulose wrote:
> On 14/04/16 18:39, Will Deacon wrote:
>> On Wed, Apr 06, 2016 at 12:24:13PM +0100, Suzuki K Poulose wrote:
>>> CPU Errata work arounds are detected and applied to the
>>> kernel code at boot time and the data is then freed up.
>>> If a new hotplugged CPU requires a work around which
>>> was not applied at boot time, there is nothing we can
>>> do but simply fail the booting.
>>
>> Hmm, wouldn't it be better not to free the alternative text for errata
>> workarounds instead?
>
> We could. I don't have a strong opinion. If there are no objections, I could
> adopt it.

The alternatives have been merged to .init by :

commit 9aa4ec1571da6236 ("arm64: mm: fold alternatives into .init")

Mark,

Do you have any concerns on applying alternatives for CPUs turned online later ?
We have to revert the patch above to get going

Suzuki