• Nathan Fontenot's avatar
    powerpc/pseries/memory-hotplug: Only update DT once per memory DLPAR request · 9271304c
    Nathan Fontenot authored
    [ Upstream commit 063b8b12 ]
    
    The updates to powerpc numa and memory hotplug code now use the
    in-kernel LMB array instead of the device tree. This change allows the
    pseries memory DLPAR code to only update the device tree once after
    successfully handling a DLPAR request.
    
    Prior to the in-kernel LMB array, the numa code looked up the affinity
    for memory being added in the device tree, the code now looks this up
    in the LMB array. This change means the memory hotplug code can just
    update the affinity for an LMB in the LMB array instead of updating
    the device tree.
    
    This also provides a savings in kernel memory. When updating the
    device tree old properties are never free'ed since there is no
    usecount on properties. This behavior leads to a new copy of the
    property being allocated every time a LMB is added or removed (i.e. a
    request to add 100 LMBs creates 100 new copies of the property). With
    this update only a single new property is created when a DLPAR request
    completes successfully.
    Signed-off-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    9271304c
hotplug-memory.c 22.9 KB