[PATCH v12 04/31] arm64/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT

[Laurent Dufour]

Le 23/04/2019 à 18:19, Mark Rutland a écrit :
> On Tue, Apr 23, 2019 at 05:36:31PM +0200, Laurent Dufour wrote:
>> Le 18/04/2019 à 23:51, Jerome Glisse a écrit :
>>> On Tue, Apr 16, 2019 at 03:41:56PM +0100, Mark Rutland wrote:
>>>> On Tue, Apr 16, 2019 at 04:31:27PM +0200, Laurent Dufour wrote:
>>>>> Le 16/04/2019 à 16:27, Mark Rutland a écrit :
>>>>>> On Tue, Apr 16, 2019 at 03:44:55PM +0200, Laurent Dufour wrote:
>>>>>>> From: Mahendran Ganesh <opensource.ganesh at gmail.com>
>>>>>>>
>>>>>>> Set ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT for arm64. This
>>>>>>> enables Speculative Page Fault handler.
>>>>>>>
>>>>>>> Signed-off-by: Ganesh Mahendran <opensource.ganesh at gmail.com>
>>>>>>
>>>>>> This is missing your S-o-B.
>>>>>
>>>>> You're right, I missed that...
>>>>>
>>>>>> The first patch noted that the ARCH_SUPPORTS_* option was there because
>>>>>> the arch code had to make an explicit call to try to handle the fault
>>>>>> speculatively, but that isn't addeed until patch 30.
>>>>>>
>>>>>> Why is this separate from that code?
>>>>>
>>>>> Andrew was recommended this a long time ago for bisection purpose. This
>>>>> allows to build the code with CONFIG_SPECULATIVE_PAGE_FAULT before the code
>>>>> that trigger the spf handler is added to the per architecture's code.
>>>>
>>>> Ok. I think it would be worth noting that in the commit message, to
>>>> avoid anyone else asking the same question. :)
>>>
>>> Should have read this thread before looking at x86 and ppc :)
>>>
>>> In any case the patch is:
>>>
>>> Reviewed-by: Jérôme Glisse <jglisse at redhat.com>
>>
>> Thanks Mark and Jérôme for reviewing this.
>>
>> Regarding the change in the commit message, I'm wondering if this would be
>> better to place it in the Series's letter head.
>>
>> But I'm fine to put it in each architecture's commit.
> 
> I think noting it in both the cover letter and specific patches is best.
> 
> Having something in the commit message means that the intent will be
> clear when the patch is viewed in isolation (e.g. as they will be once
> merged).
> 
> All that's necessary is something like:
> 
>    Note that this patch only enables building the common speculative page
>    fault code such that this can be bisected, and has no functional
>    impact. The architecture-specific code to make use of this and enable
>    the feature will be addded in a subsequent patch.

Thanks Mark, will do it this way.


> Thanks,
> Mark.