• Yinghai Lu's avatar
    x86, numa: For each node, register the memory blocks actually used · 73cf624d
    Yinghai Lu authored
    Russ reported SGI UV is broken recently. He said:
    
    | The SRAT table shows that memory range is spread over two nodes.
    |
    | SRAT: Node 0 PXM 0 100000000-800000000
    | SRAT: Node 1 PXM 1 800000000-1000000000
    | SRAT: Node 0 PXM 0 1000000000-1080000000
    |
    |Previously, the kernel early_node_map[] would show three entries
    |with the proper node.
    |
    |[    0.000000]     0: 0x00100000 -> 0x00800000
    |[    0.000000]     1: 0x00800000 -> 0x01000000
    |[    0.000000]     0: 0x01000000 -> 0x01080000
    |
    |The problem is recent community kernel early_node_map[] shows
    |only two entries with the node 0 entry overlapping the node 1
    |entry.
    |
    |    0: 0x00100000 -> 0x01080000
    |    1: 0x00800000 -> 0x01000000
    
    After looking at the changelog, Found out that it has been broken for a while by
    following commit
    
    |commit 8716273c
    
    
    |Author: David Rientjes <rientjes@google.com>
    |Date:   Fri Sep 25 15:20:04 2009 -0700
    |
    |    x86: Export srat physical topology
    
    Before that commit, register_active_regions() is called for every SRAT memory
    entry right away.
    
    Use nodememblk_range[] instead of nodes[] in order to make sure we
    capture the actual memory blocks registered with each node.  nodes[]
    contains an extended range which spans all memory regions associated
    with a node, but that does not mean that all the memory in between are
    included.
    Reported-by: default avatarRuss Anderson <rja@sgi.com>
    Tested-by: default avatarRuss Anderson <rja@sgi.com>
    Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
    LKML-Reference: <4CB27BDF.5000800@kernel.org>
    Acked-by: default avatarDavid Rientjes <rientjes@google.com>
    Cc: <stable@kernel.org> 2.6.33 .34 .35 .36
    Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
    73cf624d