I have read about the kexec/kdump facilities, we know that crashed/panic'ed kernel is made available via /proc/vmcore.
I have heard people use kexec based booting to bypass EFI/BIOS/FW initialization stages to speed up their OS patching activities on production machines. This implies that those machines continue using the capture kernels for the rest of their processing/uptime.
I could not find a clear mention of capture kernel's ability to reclaim the old memory areas that have been preserved for taking a kdump. Can the capture kernel discard those preserved memory contents after the dump has been saved?
It's true that the capture kernel would be running from a "non-standard" memory location due to it being a "relocatable" kernel, but can it utilize/free up all other memory and continue to be used as the main kernel for production uses?