• David Rientjes's avatar
    x86_64: fake pxm-to-node mapping for fake numa · 3484d798
    David Rientjes authored
    For NUMA emulation, our SLIT should represent the true NUMA topology of the
    system but our proximity domain to node ID mapping needs to reflect the
    emulated state.
    When NUMA emulation has successfully setup fake nodes on the system, a new
    function, acpi_fake_nodes() is called.  This function determines the proximity
    domain (_PXM) for each true node found on the system.  It then finds which
    emulated nodes have been allocated on this true node as determined by its
    starting address.  The node ID to PXM mapping is changed so that each fake
    node ID points to the PXM of the true node that it is located on.
    If the machine failed to register a SLIT, then we assume there is no special
    requirement for emulated node affinity so we use the default LOCAL_DISTANCE,
    which is newly exported to this code, as our measurement if the emulated nodes
    appear in the same PXM.  Otherwise, we use REMOTE_DISTANCE.
    PXM_INVAL and NID_INVAL are also exported to the ACPI header file so that we
    can compare node_to_pxm() results in generic code (in this case, the SRAT
    Cc: Len Brown <lenb@kernel.org>
    Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarAndi Kleen <ak@suse.de>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
numa.c 6.35 KB