linux-kernel - Re: [PATCH v3 01/13] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec

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Date:   Mon, 26 Jun 2023 11:33:07 -0500
From:   Eric DeVolder <eric.devolder@...cle.com>
To:     "Russell King (Oracle)" <linux@...linux.org.uk>
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Subject: Re: [PATCH v3 01/13] kexec: consolidate kexec and crash options into
 kernel/Kconfig.kexec



On 6/26/23 11:19, Russell King (Oracle) wrote:
> On Mon, Jun 26, 2023 at 12:13:20PM -0400, Eric DeVolder wrote:
>> +config KEXEC
>> +	bool "Enable kexec system call"
>> +	default ARCH_DEFAULT_KEXEC
>> +	depends on ARCH_SUPPORTS_KEXEC
>> +	select KEXEC_CORE
>> +	help
>> +	  kexec is a system call that implements the ability to shutdown your
>> +	  current kernel, and to start another kernel. It is like a reboot
>> +	  but it is independent of the system firmware. And like a reboot
>> +	  you can start any kernel with it, not just Linux.
>> +
>> +	  The name comes from the similarity to the exec system call.
>> +
>> +	  It is an ongoing process to be certain the hardware in a machine
>> +	  is properly shutdown, so do not be surprised if this code does not
>> +	  initially work for you. As of this writing the exact hardware
>> +	  interface is strongly in flux, so no good recommendation can be
>> +	  made.
> 
> Is this last paragraph still true? Is the hardware interface still
> "strongly in flux" ?
> 
Russell,
In short, I don't know. Specifically with respect to the verbage you point out, it was
present in most of the original Kconfig descriptions. Some archs are probably in better
shape than others, but overall I've always see people issue caution statements around
kexec/kdump.
$0.02
eric