1. 14 Jul, 2017 1 commit
  2. 10 Jul, 2017 1 commit
    • Michal Hocko's avatar
      mm, memory_hotplug: support movable_node for hotpluggable nodes · 9f123ab5
      Michal Hocko authored
      movable_node kernel parameter allows making hotpluggable NUMA nodes to
      put all the hotplugable memory into movable zone which allows more or
      less reliable memory hotremove.  At least this is the case for the NUMA
      nodes present during the boot (see find_zone_movable_pfns_for_nodes).
      
      This is not the case for the memory hotplug, though.
      
      	echo online > /sys/devices/system/memory/memoryXYZ/state
      
      will default to a kernel zone (usually ZONE_NORMAL) unless the
      particular memblock is already in the movable zone range which is not
      the case normally when onlining the memory from the udev rule context
      for a freshly hotadded NUMA node.  The only option currently is to have
      a special udev rule to echo online_movable to all memblocks belonging to
      such a node which is rather clumsy.  Not to mention this is inconsistent
      as well because what ended up in the movable zone during the boot will
      end up in a kernel zone after hotremove & hotadd without special care.
      
      It would be nice to reuse memblock_is_hotpluggable but the runtime
      hotplug doesn't have that information available because the boot and
      hotplug paths are not shared and it would be really non trivial to make
      them use the same code path because the runtime hotplug doesn't play
      with the memblock allocator at all.
      
      Teach move_pfn_range that MMOP_ONLINE_KEEP can use the movable zone if
      movable_node is enabled and the range doesn't overlap with the existing
      normal zone.  This should provide a reasonable default onlining
      strategy.
      
      Strictly speaking the semantic is not identical with the boot time
      initialization because find_zone_movable_pfns_for_nodes covers only the
      hotplugable range as described by the BIOS/FW.  From my experience this
      is usually a full node though (except for Node0 which is special and
      never goes away completely).  If this turns out to be a problem in the
      real life we can tweak the code to store hotplug flag into memblocks but
      let's keep this simple now.
      
      Link: http://lkml.kernel.org/r/20170612111227.GI7476@dhcp22.suse.czSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Acked-by: default avatarReza Arbab <arbab@linux.vnet.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
      Cc: <qiuxishi@huawei.com>
      Cc: Kani Toshimitsu <toshi.kani@hpe.com>
      Cc: <slaoub@gmail.com>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9f123ab5
  3. 28 Feb, 2017 1 commit
  4. 24 Oct, 2016 1 commit
  5. 20 May, 2016 1 commit
    • Vitaly Kuznetsov's avatar
      memory_hotplug: introduce CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE · 8604d9e5
      Vitaly Kuznetsov authored
      This patchset continues the work I started with commit 31bc3858
      ("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.
      
      This patch (of 2):
      
      Introduce config option to set the default value for memory hotplug
      onlining policy (/sys/devices/system/memory/auto_online_blocks).  The
      reason one would want to turn this option on are to have early onlining
      for hotpluggable memory available at boot and to not require any
      userspace actions to make memory hotplug work.
      
      [akpm@linux-foundation.org: tweak Kconfig text]
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Lennart Poettering <lennart@poettering.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8604d9e5
  6. 15 Mar, 2016 1 commit
    • Vitaly Kuznetsov's avatar
      memory-hotplug: add automatic onlining policy for the newly added memory · 31bc3858
      Vitaly Kuznetsov authored
      Currently, all newly added memory blocks remain in 'offline' state
      unless someone onlines them, some linux distributions carry special udev
      rules like:
      
        SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online"
      
      to make this happen automatically.  This is not a great solution for
      virtual machines where memory hotplug is being used to address high
      memory pressure situations as such onlining is slow and a userspace
      process doing this (udev) has a chance of being killed by the OOM killer
      as it will probably require to allocate some memory.
      
      Introduce default policy for the newly added memory blocks in
      /sys/devices/system/memory/auto_online_blocks file with two possible
      values: "offline" which preserves the current behavior and "online"
      which causes all newly added memory blocks to go online as soon as
      they're added.  The default is "offline".
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Reviewed-by: default avatarDaniel Kiper <daniel.kiper@oracle.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Daniel Kiper <daniel.kiper@oracle.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Xishi Qiu <qiuxishi@huawei.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Igor Mammedov <imammedo@redhat.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      31bc3858
  7. 20 Mar, 2015 1 commit
  8. 27 Feb, 2015 1 commit
  9. 10 Oct, 2014 1 commit
    • Zhang Zhen's avatar
      memory-hotplug: add sysfs valid_zones attribute · ed2f2400
      Zhang Zhen authored
      Currently memory-hotplug has two limits:
      
      1. If the memory block is in ZONE_NORMAL, you can change it to
         ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE.
      
      2. If the memory block is in ZONE_MOVABLE, you can change it to
         ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL.
      
      With this patch, we can easy to know a memory block can be onlined to
      which zone, and don't need to know the above two limits.
      
      Updated the related Documentation.
      
      [akpm@linux-foundation.org: use conventional comment layout]
      [akpm@linux-foundation.org: fix build with CONFIG_MEMORY_HOTREMOVE=n]
      [akpm@linux-foundation.org: remove unused local zone_prev]
      Signed-off-by: default avatarZhang Zhen <zhenzhang.zhang@huawei.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ed2f2400
  10. 23 Jun, 2014 1 commit
  11. 04 Jun, 2014 1 commit
  12. 27 Aug, 2013 1 commit
  13. 22 Jul, 2013 1 commit
    • Toshi Kani's avatar
      mm/hotplug, x86: Disable ARCH_MEMORY_PROBE by default · a0842b70
      Toshi Kani authored
      CONFIG_ARCH_MEMORY_PROBE enables the
      /sys/devices/system/memory/probe interface, which allows a given
      memory address to be hot-added as follows:
      
       # echo start_address_of_new_memory > /sys/devices/system/memory/probe
      
      (See Documentation/memory-hotplug.txt for more details.)
      
      This probe interface is required on powerpc. On x86, however,
      ACPI notifies a memory hotplug event to the kernel, which
      performs its hotplug operation as the result.
      
      Therefore, regular users do not need this interface on x86. This probe
      interface is also error-prone and misleading that the kernel blindly
      adds a given memory address without checking if the memory is present
      on the system; no probing is done despite of its name.
      
      The kernel crashes when a user requests to online a memory block
      that is not present on the system. This interface is currently
      used for testing as it can fake a hotplug event.
      
      This patch disables CONFIG_ARCH_MEMORY_PROBE by default on x86,
      adds its Kconfig menu entry on x86, and clarifies its use in
      Documentation/ memory-hotplug.txt.
      Signed-off-by: default avatarToshi Kani <toshi.kani@hp.com>
      Acked-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: linux-mm@kvack.org
      Cc: dave@sr71.net
      Cc: isimatu.yasuaki@jp.fujitsu.com
      Cc: tangchen@cn.fujitsu.com
      Cc: vasilis.liaskovitis@profitbricks.com
      Link: http://lkml.kernel.org/r/1374256068-26016-1-git-send-email-toshi.kani@hp.com
      [ Edited it slightly. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a0842b70
  14. 13 Dec, 2012 1 commit
  15. 12 Dec, 2012 2 commits
    • Lai Jiangshan's avatar
      mm, memory-hotplug: dynamic configure movable memory and portion memory · 511c2aba
      Lai Jiangshan authored
      Add online_movable and online_kernel for logic memory hotplug.  This is
      the dynamic version of "movablecore" & "kernelcore".
      
      We have the same reason to introduce it as to introduce "movablecore" &
      "kernelcore".  It has the same motive as "movablecore" & "kernelcore", but
      it is dynamic/running-time:
      
      o We can configure memory as kernelcore or movablecore after boot.
      
        Userspace workload is increased, we need more hugepage, we can't use
        "online_movable" to add memory and allow the system use more
        THP(transparent-huge-page), vice-verse when kernel workload is increase.
      
        Also help for virtualization to dynamic configure host/guest's memory,
        to save/(reduce waste) memory.
      
        Memory capacity on Demand
      
      o When a new node is physically online after boot, we need to use
        "online_movable" or "online_kernel" to configure/portion it as we
        expected when we logic-online it.
      
        This configuration also helps for physically-memory-migrate.
      
      o all benefit as the same as existed "movablecore" & "kernelcore".
      
      o Preparing for movable-node, which is very important for power-saving,
        hardware partitioning and high-available-system(hardware fault
        management).
      
      (Note, we don't introduce movable-node here.)
      
      Action behavior:
      When a memoryblock/memorysection is onlined by "online_movable", the kernel
      will not have directly reference to the page of the memoryblock,
      thus we can remove that memory any time when needed.
      
      When it is online by "online_kernel", the kernel can use it.
      When it is online by "online", the zone type doesn't changed.
      
      Current constraints:
      Only the memoryblock which is adjacent to the ZONE_MOVABLE
      can be online from ZONE_NORMAL to ZONE_MOVABLE.
      
      [akpm@linux-foundation.org: use min_t, cleanups]
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Minchan Kim <minchan.kim@gmail.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Greg KH <greg@kroah.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      511c2aba
    • Lai Jiangshan's avatar
      memory_hotplug: fix possible incorrect node_states[N_NORMAL_MEMORY] · d9713679
      Lai Jiangshan authored
      Currently memory_hotplug only manages the node_states[N_HIGH_MEMORY], it
      forgets to manage node_states[N_NORMAL_MEMORY].  This may cause
      node_states[N_NORMAL_MEMORY] to become incorrect.
      
      Example, if a node is empty before online, and we online a memory which is
      in ZONE_NORMAL.  And after online, node_states[N_HIGH_MEMORY] is correct,
      but node_states[N_NORMAL_MEMORY] is incorrect, the online code doesn't set
      the new online node to node_states[N_NORMAL_MEMORY].
      
      The same thing will happen when offlining (the offline code doesn't clear
      the node from node_states[N_NORMAL_MEMORY] when needed).  Some memory
      managment code depends node_states[N_NORMAL_MEMORY], so we have to fix up
      the node_states[N_NORMAL_MEMORY].
      
      We add node_states_check_changes_online() and
      node_states_check_changes_offline() to detect whether
      node_states[N_HIGH_MEMORY] and node_states[N_NORMAL_MEMORY] are changed
      while hotpluging.
      
      Also add @status_change_nid_normal to struct memory_notify, thus the
      memory hotplug callbacks know whether the node_states[N_NORMAL_MEMORY] are
      changed.  (We can add a @flags and reuse @status_change_nid instead of
      introducing @status_change_nid_normal, but it will add much more
      complexity in memory hotplug callback in every subsystem.  So introducing
      @status_change_nid_normal is better and it doesn't change the sematics of
      @status_change_nid)
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Minchan Kim <minchan.kim@gmail.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Rob Landley <rob@landley.net>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d9713679
  16. 16 Apr, 2012 1 commit
  17. 04 Feb, 2011 1 commit
  18. 15 Dec, 2009 1 commit
    • Alex Chiang's avatar
      mm: add numa node symlink for memory section in sysfs · dee5d0d5
      Alex Chiang authored
      Commit c04fc586 (mm: show node to memory section relationship with
      symlinks in sysfs) created symlinks from nodes to memory sections, e.g.
      
      /sys/devices/system/node/node1/memory135 -> ../../memory/memory135
      
      If you're examining the memory section though and are wondering what node
      it might belong to, you can find it by grovelling around in sysfs, but
      it's a little cumbersome.
      
      Add a reverse symlink for each memory section that points back to the
      node to which it belongs.
      Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
      Cc: Gary Hade <garyhade@us.ibm.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Greg KH <greg@kroah.com>
      Cc: Randy Dunlap <randy.dunlap@oracle.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dee5d0d5
  19. 12 Jun, 2009 1 commit
  20. 06 Jan, 2009 1 commit
    • Gary Hade's avatar
      mm: show node to memory section relationship with symlinks in sysfs · c04fc586
      Gary Hade authored
      Show node to memory section relationship with symlinks in sysfs
      
      Add /sys/devices/system/node/nodeX/memoryY symlinks for all
      the memory sections located on nodeX.  For example:
      /sys/devices/system/node/node1/memory135 -> ../../memory/memory135
      indicates that memory section 135 resides on node1.
      
      Also revises documentation to cover this change as well as updating
      Documentation/ABI/testing/sysfs-devices-memory to include descriptions
      of memory hotremove files 'phys_device', 'phys_index', and 'state'
      that were previously not described there.
      
      In addition to it always being a good policy to provide users with
      the maximum possible amount of physical location information for
      resources that can be hot-added and/or hot-removed, the following
      are some (but likely not all) of the user benefits provided by
      this change.
      Immediate:
        - Provides information needed to determine the specific node
          on which a defective DIMM is located.  This will reduce system
          downtime when the node or defective DIMM is swapped out.
        - Prevents unintended onlining of a memory section that was
          previously offlined due to a defective DIMM.  This could happen
          during node hot-add when the user or node hot-add assist script
          onlines _all_ offlined sections due to user or script inability
          to identify the specific memory sections located on the hot-added
          node.  The consequences of reintroducing the defective memory
          could be ugly.
        - Provides information needed to vary the amount and distribution
          of memory on specific nodes for testing or debugging purposes.
      Future:
        - Will provide information needed to identify the memory
          sections that need to be offlined prior to physical removal
          of a specific node.
      
      Symlink creation during boot was tested on 2-node x86_64, 2-node
      ppc64, and 2-node ia64 systems.  Symlink creation during physical
      memory hot-add tested on a 2-node x86_64 system.
      Signed-off-by: default avatarGary Hade <garyhade@us.ibm.com>
      Signed-off-by: default avatarBadari Pulavarty <pbadari@us.ibm.com>
      Acked-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c04fc586
  21. 22 Oct, 2007 1 commit
  22. 11 Aug, 2007 1 commit