Re: [PATCH v6 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables

[Dirk van der Merwe <dirk.vandermerwe@netronome.com>]

On 5/13/19 8:33 PM, Baoquan He wrote:
> On 05/14/19 at 11:22am, Dave Young wrote:
>> On 05/13/19 at 04:06pm, Baoquan He wrote:
>>> Hi Dave,
>>>
>>> On 05/13/19 at 09:50am, Borislav Petkov wrote:
>>>> On Mon, May 13, 2019 at 03:32:54PM +0800, Baoquan He wrote:
>>>>> This is a critical bug which breaks memory hotplug,
>>>> Please concentrate and stop the blabla:
>>>>
>>>> 36f0c423552d ("x86/boot: Disable RSDP parsing temporarily")
>>>>
>>>> already explains what the deal is. This code was *purposefully* disabled
>>>> because we ran out of time and it broke a couple of machines. Don't make
>>> I remember your machine is the one on whihc the issue is reported. Could
>>> you also test it and confirm if these all things found ealier are
>>> cleared out?
>>>
>> I did some tests on the laptop,  thing is:
>> 1. apply the 3 patches (two you posted + Boris's revert commit 52b922c3d49c)
>>     on latest Linus master branch, everything works fine.
>>
>> 2. build and test the tip/next-merge-window branch, kernel hangs early
>> without output, (both 1st boot and kexec boot)
> Thanks, Dave.
>
> Yeah, I also tested on a HP machine, problem reprodued on the current
> master branch when revert commit 52b922c3d49c.
>
> Then apply these two patches, problem solved.
>
> Tried boris's next-merge-window branch too, kexec works very well.
>
> Dirk, Junichi, feel free to add your test result if you have time.


I tested this with the patches (plus revert of the workaround) applied 
against stable 5.1 and it works fine for me there. Thanks!

Where can I find the next-merge-window tree?

I can test against that too.


Best regards

Dirk