Hello Kexec community, I am writing to see if it is possible to receive some assistance to figure out why the kexec program is not working properly on one of my system types. While I have successfully added the kexec technology to many of our systems running various processors and kernel versions there is one system in particular that has intermittent problems. The errant system type fails less than 5% of the time because it freezes when attempting to begin running the backup crash kernel stored in memory. I believe that the basic framework is correct but something is going amiss when trying to start the backup crash kernel. My system is running: kexec-tools version 2.0.4 Linux kernel 2.6.35.14 Xeon X3450 processor 16G of memory To gather more information I placed some debug printk statements into the kexec kernel code to determine the code path following a memory exception OOPS event. I verified following code path: no_context() - arch/x86/mm/fault.c oops_end() - arch/x86/kernel/dumpstack.c crash_kexec() - kernel/kexec.c machine_kexec() - arch/x86/kernel/machine_kexec_64.c load_segments() - Assembly module I have been able to get the kexec and kdump functionality to work properly on a nearly identical platform using the exact same 2.6.35.14 kernel file but running upon Intel X3430 processor. My Linux startup command line is: auto BOOT_IMAGE=3D-5.3.0 ro root=805 console=tty0 \ console=ttyS0,9600 memmap=1G$4G \ crashkernel=128M at 32M oops=panic And my kexec command is: /usr/sbin/kexec -p /boot/bzImage-2.6.35.14-sf.westmere-37 \ --append=" root=/dev/sda5 1 irqpoll maxcpus=1 \ reset_devices console=tty0 console=ttyS0,9600 \ memmap=1G$4G oops=panic" We have a customer network interface card that uses the memory segment ?memmap=1G$4G? and can be performing a DMA into main memory over the PCI bus when the intentional memory exception event occurs. I tried to place the backup kernel far away from this at an offset of just 32M in the kernel OS space. The other systems that do not fail have these cards as well so this card would not be the sole reason for the failure. If there is anyone that can provide any suggestions or advice on how to proceed that would be very much appreciated. Kind regards, Patrick Lengel
