How to understand "high" or "low" in crashkernel configuration?

[xiaonan830818@xxxxxxxxx (Nan Xiao)]

Hi all,

When I use SuSE default Kdump configuration, I find there is "high" or "low" in
crashkernel's value, and it likes this:

    crashkernel=xxM,high Or crashkernel=xxM,low

But from this document(https://www.kernel.org/doc/Documentation/kdump/kdump.txt),
I can't find explanation of "high" or "low". How to understand it?

Thanks very much in advance!

Best Regards
Nan Xiao