* Vivek Goyal <vgoyal at in.ibm.com> [2007-09-11 08:15]: > > "offset" seems to be optional in the new syntax. What happens if user does > not specify offset. I think crash_base will be set to zero and system will > try to reserve x amount of memory start at zero? That would fail? That's handled in the architecture specific code -- because it's different on each architecture and the architecture specific code does memory reservation. IA64 already can handle this case (on IA64, specifying 0 is the same than leaving out the base address, and that's why I wanted to keep that semantics). I think it doesn't also make sense on i386/x86_64 to choose 0 as real base address, because the value below 1 MB is special for booting ... > I think we should add some intelligence for automatic selection of "offset" > if user has not specified one. Automatically choose a chunk of free memory. > This takes away the headache from user for selecting a right place. In fact > one "offset" might not be valid for all the systems. I remember, somebody > had reported that ACPI tables were mapped lower in the address space and > reserving memory for kdump had failed. I think you're right -- with the relocatable kernel it makes sense to have the kernel to decide where to reservate that memory. But that's beyond of the scope of that patch series -- however, I can come up with a solution, after that patch has been finished. Thanks, Bernhard
