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Date:   Thu, 23 Nov 2023 14:43:00 +0100
From:   Alexander Gordeev <agordeev@linux.ibm.com>
To:     Baoquan He <bhe@redhat.com>
Cc:     linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org,
        akpm@linux-foundation.org, ignat@cloudflare.com,
        eric_devolder@yahoo.com
Subject: Re: [PATCH 3/3] s390/Kconfig: drop select of KEXEC
Message-ID: <ZV9W5AmmYhCFmN9e@li-008a6a4c-3549-11b2-a85c-c5cc2836eea2.ibm.com>
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 <20231123073652.507034-4-bhe@redhat.com>
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On Thu, Nov 23, 2023 at 03:36:52PM +0800, Baoquan He wrote:

Hi Baoquan,

> No proof is found to require that S390 architecture has to select
> KEXEC. At least from my testing at below, dropping select of KEXEC won't
> impact anything.

It does impact the outcome of defconfigs.
Namely, CONFIG_KEXEC is not set with this patch.

> ===testing 1===
> CONFIG_CRASH_CORE=y
> CONFIG_KEXEC_CORE=y
> CONFIG_CRASH_DUMP=y
> ===
> 
> ===testing 2===
> CONFIG_CRASH_CORE=y
> CONFIG_KEXEC_CORE=y
> CONFIG_KEXEC_FILE=y
> CONFIG_CRASH_DUMP=y
> ===

Unfortunately, I do not quite realize what these testings were
and what is the difference between the two.

> So drop the select of KEXEC now.

I suggest dropping this patch. Once the previous two are upstream
we would remove 'select KEXEC' from Kconfig together with defconfig
updates.

> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
>  arch/s390/Kconfig | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index 3bec98d20283..1aec2e692dca 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -217,7 +217,6 @@ config S390
>  	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
>  	select IOMMU_HELPER		if PCI
>  	select IOMMU_SUPPORT		if PCI
> -	select KEXEC
>  	select MMU_GATHER_MERGE_VMAS
>  	select MMU_GATHER_NO_GATHER
>  	select MMU_GATHER_RCU_TABLE_FREE
> -- 

Thanks!