On 08/23/24 at 08:16pm, John Paul Adrian Glaubitz wrote:

Hi Geert,

On Fri, 2024-08-23 at 15:13 +0200, Geert Uytterhoeven wrote:

quoted

IMHO CRASH_DUMP should just default to n, like most kernel options, as
it enables non-trivial extra functionality: the kernel source tree has
more than 100 locations that check if CONFIG_CRASH_DUMP is enabled.

I guess we should then revert that part of Baoquan's original patch.

quoted

What is so special about CRASH_DUMP, that it should be enabled by
default?

Let's ask Baoquan who made the original change to enable CRASH_DUMP by default.

Sorry for late reply.

It's me who enabled it by default when I clean up the messy Kconfig items
related to kexec/kdump. Before the clean up, CONFIG_CRASH_DUMP only
controlled a very small file including sevearl functions and macro
definitions. But kernel codes took CRASH_DUMP as switch of kdump.

About why it's enabled by default, as Michael has explained in another
thread, distros usualy needs to enable it by default because vmcore
dumping is a very important feature on servers, even guest instances. 
Even though kdump codes are enabled to built in, not providing
crashkernel= value won't make vmcore dumping take effect, it won't cost
system resources in that case.

Thanks
Baoquan