Re: Query about kdump_msg hook into crash_kexec()

Américo Wang
2011-02-01T07:27:42Z

On Mon, Jan 31, 2011 at 05:59:39PM -0500, Vivek Goyal wrote:
>
>Anyway, if an image is loaded and we have setup to capture dump also
>why do we need to save kmsg with the help of an helper. I am assuming
>this is more of a debugging aid if we have no other way to capture the
>kernel log buffer. So if somebody has setup kdump to capture the
>vmcore, why to call another handler which tries to save part of the
>vmcore (kmsg) separately.
>

Well, kmsg dumper is not only for panic/oops, it can also save kernel
messages when the system is reboot/halt.

Yeah, it is true that vmcore contains log_buf, but I think the users
of ramoops/mtdoops are mainly those who don't have kdump configured
in their kernels, they are cheaper than kdump, but less powerful.

Thanks.