[PATCH 0/2] memory_hotplug: introduce config and command line options to set the default onlining policy

Vitaly Kuznetsov
2016-04-06T13:45:20Z

This patchset continues the work I started with:

commit 31bc3858ea3ebcc3157b3f5f0e624c5962f5a7a6
Author: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Tue Mar 15 14:56:48 2016 -0700

memory-hotplug: add automatic onlining policy for the newly added memory

Initially I was going to stop there and bring the policy setting logic to
userspace. I met two issues on this way:

1) It is possible to have memory hotplugged at boot (e.g. with QEMU). These
blocks stay offlined if we turn the onlining policy on by userspace.

2) My attempt to bring this policy setting to systemd failed, systemd
maintainers suggest to change the default in kernel or ... to use tmpfiles.d
to alter the policy (which looks like a hack to me):
https://github.com/systemd/systemd/pull/2938

Here I suggest to add a config option to set the default value for the policy
and a kernel command line parameter to make the override.

Vitaly Kuznetsov (2):
memory_hotplug: introduce CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
memory_hotplug: introduce memhp_default_state= command line parameter

Documentation/kernel-parameters.txt | 8 ++++++++
Documentation/memory-hotplug.txt | 9 +++++----
mm/Kconfig | 16 ++++++++++++++++
mm/memory_hotplug.c | 15 +++++++++++++++
4 files changed, 44 insertions(+), 4 deletions(-)

--
2.5.5