• Nikanth Karthikesan's avatar
    x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA · 50f2d7f6
    Nikanth Karthikesan authored
    commit d9c2d5ac "x86, numa: Use near(er)
    online node instead of roundrobin for NUMA" changed NUMA initialization on
    Intel to choose the nearest online node or first node.  Fake NUMA would be
    better of with round-robin initialization, instead of the all CPUS on
    first node.  Change the choice of first node, back to round-robin.
    
    For testing NUMA kernel behaviour without cpusets and NUMA aware
    applications, it would be better to have cpus in different nodes, rather
    than all in a single node.  With cpusets migration of tasks scenarios
    cannot not be tested.
    
    I guess having it round-robin shouldn't affect the use cases for all cpus
    on the first node.
    
    The code comments in arch/x86/mm/numa_64.c:759 indicate that this used to
    be the case, which was changed by commit d9c2d5ac.  It changed from
    roundrobin to nearer or first node.  And I couldn't find any reason for
    this change in its changelog.
    Signed-off-by: default avatarNikanth Karthikesan <knikanth@suse.de>
    Cc: David Rientjes <rientjes@google.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    50f2d7f6
intel.c 13.5 KB