04 Feb, 2011

1 commit

  • Update the memory sysfs code such that each sysfs memory directory is now
    considered a memory block that can span multiple memory sections per
    memory block. The default size of each memory block is SECTION_SIZE_BITS
    to maintain the current behavior of having a single memory section per
    memory block (i.e. one sysfs directory per memory section).

    For architectures that want to have memory blocks span multiple
    memory sections they need only define their own memory_block_size_bytes()
    routine.

    Update the memory hotplug documentation to reflect the new behaviors of
    memory blocks reflected in sysfs.

    Signed-off-by: Nathan Fontenot
    Reviewed-by: Robin Holt
    Reviewed-by: KAMEZAWA Hiroyuki
    Signed-off-by: Greg Kroah-Hartman

    Nathan Fontenot
     

16 Dec, 2009

1 commit

  • Commit c04fc586c (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: Alex Chiang
    Cc: Gary Hade
    Cc: Badari Pulavarty
    Cc: Ingo Molnar
    Acked-by: David Rientjes
    Cc: Greg KH
    Cc: Randy Dunlap
    Cc: David Rientjes
    Cc: KOSAKI Motohiro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alex Chiang
     

13 Jun, 2009

1 commit


07 Jan, 2009

1 commit

  • 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: Gary Hade
    Signed-off-by: Badari Pulavarty
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Gary Hade
     

22 Oct, 2007

1 commit


12 Aug, 2007

1 commit

  • This is add a document for memory hotplug to describe "How to use" and
    "Current status".

    Signed-off-by: KAMEZAWA Hiroyuki
    Signed-off-by: Yasunori Goto
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Yasunori Goto