Re: [V5 PATCH 00/26] mm, memory-hotplug: dynamic configure movable memory and introduce movable node

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

HI Lai,

The patch-set is huge. Therefore, we hesitate to read the patch-set. 
I think the patch-set has multiple feature developments. 
  - Development of online_movable [PATCH 1 - 3]
  - Cleanup node_state_attr [PATCH 4]
  - Introduce N_MEMORY [PATCH 5 - 18]
  - Development of kernelcore_max_addr [PATCH 19 - 25]
  - Bug fix [PATCH 26]

Why don't you separate the patch-set into each feature development?
By separating the patch-set, many people can easily participate
in your development.

Thanks,
Yasuaki Ishimatsu

2012/10/30 0:07, Lai Jiangshan wrote:
> Movable memory is a very important concept of memory-management,
> we need to consolidate it and make use of it on systems.
> 
> Movable memory is needed for
> o	anti-fragmentation(hugepage, big-order allocation...)
> o	logic hot-remove(virtualization, Memory capacity on Demand)
> o	physic hot-remove(power-saving, hardware partitioning, hardware fault management)
> 
> All these require dynamic configuring the memory and making better utilities of memories
> and safer. We also need physic hot-remove, so we need movable node too.
> (Although some systems support physic-memory-migration, we don't require all
> memory on physic-node is movable, but movable node is still needed here
> for logic-node if we want to make physic-migration is transparent)
> 
> We add dynamic configuration commands "online_movalbe" and "online_kernel".
> We also add non-dynamic boot option kernelcore_max_addr.
> We may add some more dynamic/non-dynamic configuration in future.
> 
> 
> The patchset is based on 3.7-rc3 with these three patches already applied:
> 	https://lkml.org/lkml/2012/10/24/151
> 	https://lkml.org/lkml/2012/10/26/150
> 
> You can also simply pull all the patches from:
> 	git pull https://github.com/laijs/linux.git hotplug-next
> 
> 
> 
> Issues):
> 
> mempolicy(M_BIND) don't act well when the nodemask has movable nodes only,
> the kernel allocation will fail and the task can't create new task or other
> kernel objects.
> 
> So we change the strategy/policy
> 	when the bound nodemask has movable node(s) only, we only
> 	apply mempolicy for userspace allocation, don't apply it
> 	for kernel allocation.
> 
> CPUSET also has the same problem, but the code spread in page_alloc.c,
> and we doesn't fix it yet, we can/will change allocation strategy to one of
> these 3 strategies:
> 	1) the same strategy as mempolicy
> 	2) change cpuset, make nodemask always has at least a normal node
> 	3) split nodemask: nodemask_user and nodemask_kernel
> 
> Thoughts?
> 
> 
> 
> Patches):
> 
> patch1-3:     add online_movable and online_kernel, bot don't result movable node
> Patch4        cleanup for node_state_attr
> Patch5        introduce N_MEMORY
> Patch6-17     use N_MEMORY instead N_HIGH_MEMORY.
>                The patches are separated by subsystem,
>                Patch18 also changes the node_states initialization
> Patch18-20    Add  MOVABLE-dedicated node
> Patch21-25    Add kernelcore_max_addr
> patch26:      mempolicy handle movable node
> 
> 
> 
> 
> Changes):
> 
> change V5-V4:
> 	consolidate online_movable/online_kernel
> 	nodemask management
> 
> change V4-v3
> 	rebase.
> 	online_movable/online_kernel can create a zone from empty
> 	or empyt a zone
> 
> change V3-v2:
> 	Proper nodemask management
> 
> change V2-V1:
> 
> The original V1 patchset of MOVABLE-dedicated node is here:
> http://comments.gmane.org/gmane.linux.kernel.mm/78122
> 
> The new V2 adds N_MEMORY and a notion of "MOVABLE-dedicated node".
> And fix some related problems.
> 
> The orignal V1 patchset of "add online_movable" is here:
> https://lkml.org/lkml/2012/7/4/145
> 
> The new V2 discards the MIGRATE_HOTREMOVE approach, and use a more straight
> implementation(only 1 patch).
> 
> 
> 
> Lai Jiangshan (22):
>    mm, memory-hotplug: dynamic configure movable memory and portion
>      memory
>    memory_hotplug: handle empty zone when online_movable/online_kernel
>    memory_hotplug: ensure every online node has NORMAL memory
>    node: cleanup node_state_attr
>    node_states: introduce N_MEMORY
>    cpuset: use N_MEMORY instead N_HIGH_MEMORY
>    procfs: use N_MEMORY instead N_HIGH_MEMORY
>    memcontrol: use N_MEMORY instead N_HIGH_MEMORY
>    oom: use N_MEMORY instead N_HIGH_MEMORY
>    mm,migrate: use N_MEMORY instead N_HIGH_MEMORY
>    mempolicy: use N_MEMORY instead N_HIGH_MEMORY
>    hugetlb: use N_MEMORY instead N_HIGH_MEMORY
>    vmstat: use N_MEMORY instead N_HIGH_MEMORY
>    kthread: use N_MEMORY instead N_HIGH_MEMORY
>    init: use N_MEMORY instead N_HIGH_MEMORY
>    vmscan: use N_MEMORY instead N_HIGH_MEMORY
>    page_alloc: use N_MEMORY instead N_HIGH_MEMORY change the node_states
>      initialization
>    hotplug: update nodemasks management
>    numa: add CONFIG_MOVABLE_NODE for movable-dedicated node
>    memory_hotplug: allow online/offline memory to result movable node
>    page_alloc: add kernelcore_max_addr
>    mempolicy: fix is_valid_nodemask()
> 
> Yasuaki Ishimatsu (4):
>    x86: get pg_data_t's memory from other node
>    x86: use memblock_set_current_limit() to set memblock.current_limit
>    memblock: limit memory address from memblock
>    memblock: compare current_limit with end variable at
>      memblock_find_in_range_node()
> 
>   Documentation/cgroups/cpusets.txt   |    2 +-
>   Documentation/kernel-parameters.txt |    9 +
>   Documentation/memory-hotplug.txt    |   19 ++-
>   arch/x86/kernel/setup.c             |    4 +-
>   arch/x86/mm/init_64.c               |    4 +-
>   arch/x86/mm/numa.c                  |    8 +-
>   drivers/base/memory.c               |   27 ++--
>   drivers/base/node.c                 |   28 ++--
>   fs/proc/kcore.c                     |    2 +-
>   fs/proc/task_mmu.c                  |    4 +-
>   include/linux/cpuset.h              |    2 +-
>   include/linux/memblock.h            |    1 +
>   include/linux/memory.h              |    1 +
>   include/linux/memory_hotplug.h      |   13 ++-
>   include/linux/nodemask.h            |    5 +
>   init/main.c                         |    2 +-
>   kernel/cpuset.c                     |   32 ++--
>   kernel/kthread.c                    |    2 +-
>   mm/Kconfig                          |    8 +
>   mm/hugetlb.c                        |   24 ++--
>   mm/memblock.c                       |   10 +-
>   mm/memcontrol.c                     |   18 +-
>   mm/memory_hotplug.c                 |  283 +++++++++++++++++++++++++++++++++--
>   mm/mempolicy.c                      |   48 ++++---
>   mm/migrate.c                        |    2 +-
>   mm/oom_kill.c                       |    2 +-
>   mm/page_alloc.c                     |   76 +++++++---
>   mm/page_cgroup.c                    |    2 +-
>   mm/vmscan.c                         |    4 +-
>   mm/vmstat.c                         |    4 +-
>   30 files changed, 508 insertions(+), 138 deletions(-)
>