In kdump kernel boot, kdump kernel is booted with memmap= and add them into e820 map. Then ACPI is initialized and the kernel traverses the ACPI namespace to find entries for memory device to be hot added. This adds page table information and the kexec/kdump kernel runs out of memory. So in kdump kernel, hot plug memory need be disabled always, only exact map is trusted. Now add the kernel parameter acpi_no_memhotplug to kdump kernel cmdline. Signed-off-by: Baoquan He <bhe(a)redhat.com&gt; --- kdump.sysconfig.x86_64 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kdump.sysconfig.x86_64 b/kdump.sysconfig.x86_64 index 7e4d611..989c3c7 100644 --- a/kdump.sysconfig.x86_64 +++ b/kdump.sysconfig.x86_64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug" # Any additional kexec arguments required. In most situations, this should # be left empty -- 1.8.3.1