1. 13 May, 2010 1 commit
  2. 06 May, 2010 1 commit
    • David Rientjes's avatar
      x86: Fix fake apicid to node mapping for numa emulation · b0c4d952
      David Rientjes authored
      
      
      With NUMA emulation, it's possible for a single cpu to be bound
      to multiple nodes since more than one may have affinity if
      allocated on a physical node that is local to the cpu.
      
      APIC ids must therefore be mapped to the lowest node ids to
      maintain generic kernel use of functions such as cpu_to_node()
      that determine device affinity.  For example, if a device has
      proximity to physical node 1, for instance, and a cpu happens to
      be mapped to a higher emulated node id 8, the proximity may not
      be correctly determined by comparison in generic code even
      though the cpu may be truly local and allocated on physical node 1.
      
      When this happens, the true topology of the machine isn't
      accurately represented in the emulated environment; although
      this isn't critical to the system's uptime, any generic code
      that is NUMA aware benefits from the physical topology being
      accurately represented.
      
      This can affect any system that maps multiple APIC ids to a
      single node and is booted with numa=fake=N where N is greater
      than the number of physical nodes.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Suresh Siddha <suresh.b.siddha@intel.com>
      LKML-Reference: <alpine.DEB.2.00.1005060224140.19473@chino.kir.corp.google.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      b0c4d952
  3. 05 May, 2010 31 commits
  4. 04 May, 2010 7 commits