Hi, I have sent this as an RFC previously [1] and there haven't been any fundamental objections to the approach. The biggest concern was that if anybody starts depending on the default online semantic introduced in 4.13 merge window then this would break it [2]. I find it rather unlikely but if we are worried we can try to push this later in the release cycle. Unfortunatelly I didn't have much time to work on this sooner. This work should help Joonsoo with his CMA zone based approach when reusing MOVABLE zone. I think it will also help to remove more code from the memory hotplug (e.g. zone shrinking). Patch 1 restores original memoryXY/valid_zones semantic wrt zone ordering. This can be merged without patch 2 which removes the zone overlap restriction and defines a semantic for the default onlining. See more in the patch. Questions, concerns, objections? Shortlog Michal Hocko (2): mm, memory_hotplug: display allowed zones in the preferred ordering mm, memory_hotplug: remove zone restrictions Diffstat drivers/base/memory.c | 30 ++++++++++----- include/linux/memory_hotplug.h | 2 +- mm/memory_hotplug.c | 87 +++++++++++++++++------------------------- 3 files changed, 55 insertions(+), 64 deletions(-) [1] http://lkml.kernel.org/r/20170629073509.623-1-mhocko@xxxxxxxxxx [2] http://lkml.kernel.org/r/20170710064540.GA19185@xxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html