Re: [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory

From: Yasuaki Ishimatsu
Date: Sun Sep 09 2012 - 21:47:12 EST

Hi Wen,

2012/09/01 5:49, Andrew Morton wrote:
On Tue, 28 Aug 2012 18:00:07 +0800
wency@xxxxxxxxxxxxxx wrote:

This patch series aims to support physical memory hot-remove.

Have you had much review and testing feedback yet?

The patches can free/remove the following things:

- acpi_memory_info : [RFC PATCH 4/19]
- /sys/firmware/memmap/X/{end, start, type} : [RFC PATCH 8/19]
- iomem_resource : [RFC PATCH 9/19]
- mem_section and related sysfs files : [RFC PATCH 10-11, 13-16/19]
- page table of removed memory : [RFC PATCH 12/19]
- node and related sysfs files : [RFC PATCH 18-19/19]

If you find lack of function for physical memory hot-remove, please let me

I doubt if many people have hardware which permits physical memory
removal? How would you suggest that people with regular hardware can
test these chagnes?

How do you test the patch? As Andrew says, for hot-removing memory,
we need a particular hardware. I think so too. So many people may want
to know how to test the patch.
If we apply following patch to kvm guest, can we hot-remove memory on
kvm guest?

Yasuaki Ishimatsu

Known problems:
1. memory can't be offlined when CONFIG_MEMCG is selected.

That's quite a problem! Do you have a description of why this is the
case, and a plan for fixing it?

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