On 09/09/22 at 05:05pm, Eric DeVolder wrote: > When the kdump service is loaded, if a CPU or memory is hot > un/plugged, the crash elfcorehdr, which describes the CPUs > and memory in the system, must also be updated, else the resulting > vmcore is inaccurate (eg. missing either CPU context or memory > regions). > > The current solution utilizes udev to initiate an unload-then-reload > of the kdump image (e. kernel, initrd, boot_params, puratory and > elfcorehdr) by the userspace kexec utility. In previous posts I have > outlined the significant performance problems related to offloading > this activity to userspace. > > This patchset introduces a generic crash hot un/plug handler that > registers with the CPU and memory notifiers. Upon CPU or memory > changes, this generic handler is invoked and performs important > housekeeping, for example obtaining the appropriate lock, and then > invokes an architecture specific handler to do the appropriate > updates. > > In the case of x86_64, the arch specific handler generates a new > elfcorehdr, and overwrites the old one in memory. No involvement > with userspace needed. Thank a lot for all the effort, Eric. Hi Boris, Andrew, This version looks good to me. It introduces a framework for kdump to react mem/cpu hotplug eveut and add x86 handler. Should this go to x86 tree or mm tree? Please check what else we need do to fix or improve. Thanks Baoquan _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
