Hi, On 03 Feb 2005 02:00:51 -0700 [EMAIL PROTECTED] (Eric W. Biederman) wrote:
> A better description is probably make a list of memory regions > using an ELF header data structure in user space. > Use sys_kexec_load to put that list the dump kernel and a little > big of glue code in the reserved area. The glue code includes > a hash of all of everything so it can all be validated before > use. I see. The data structure is put on a part of loading kernel's data. > Record the register information as ELF notes in a per cpu data > area. The per cpu data areas are known and enumerated in > the list of memory regions. The kernel knows nothing about > the ELF header etc. > I see. > > 5) dump kernel: export all valid physical memory (and saved register > > information) to the user. (as /dev/oldmem /proc/vmcore ?) > > Or in user space, by just mmaping /dev/mem. That is part of the > current conversation. The only real point for putting that code in > the kernel (besides momentum) is it is a cheap way to get the exact > data structures of the kernel you are using. But since: > (a) it does not look like any primary kernel data structures need to > be examined. > (b) even simple compile options like SMP/NOSMP are enough to change > the layout of the data structures. > I think there is a pretty good case for moving all of the work to > user space. But you still need a kernel that loads and > runs in the reserved area. > I don't make sense. what do you mean ? What we want to do when the system is crashed is storing the whole physical memory (and saved register information for x86 arch) to some place (ex. a disk partition) for later analysis. So the basic requirments to the dump kernel is that: * supply a method to access whole (valid) physical memory. * supply a method to access the saved register information. Does the kdump meet this requirment ? (I am not interesting to /proc/vmcore. Constructing the vmcore image is area of analysis tools. not kernel's task.) Thanks. -- Itsuro ODA <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
