• David Rientjes's avatar
    x86: Export k8 physical topology · 8ee2debc
    David Rientjes authored
    To eventually interleave emulated nodes over physical nodes, we
    need to know the physical topology of the machine without actually
    registering it.  This does the k8 node setup in two parts:
    detection and registration.  NUMA emulation can then used the
    physical topology detected to setup the address ranges of emulated
    nodes accordingly.  If emulation isn't used, the k8 nodes are
    registered as normal.
    
    Two formals are added to the x86 NUMA setup functions: `acpi' and
    `k8'. These represent whether ACPI or K8 NUMA has been detected;
    both cannot be true at the same time.  This specifies to the NUMA
    emulation code whether an underlying physical NUMA topology exists
    and which interface to use.
    
    This patch deals solely with separating the k8 setup path into
    Northbridge detection and registration steps and leaves the ACPI
    changes for a subsequent patch.  The `acpi' formal is added here,
    however, to avoid touching all the header files again in the next
    patch.
    
    This approach also ensures emulated nodes will not span physical
    nodes so the true memory latency is not misrepresented.
    
    k8_get_nodes() may now be used to export the k8 physical topology
    of the machine for NUMA emulation.
    Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
    Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
    Cc: Yinghai Lu <yinghai@kernel.org>
    Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
    Cc: Ankita Garg <ankita@in.ibm.com>
    Cc: Len Brown <len.brown@intel.com>
    LKML-Reference: <alpine.DEB.1.00.0909251518400.14754@chino.kir.corp.google.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    8ee2debc
init_32.c 27 KB