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    cpusets: randomize node rotor used in cpuset_mem_spread_node() · 778d3b0f
    Michal Hocko 提交于
    [ This patch has already been accepted as commit 0ac0c0d0 but later
      reverted (commit 35926ff5) because it itroduced arch specific
      __node_random which was defined only for x86 code so it broke other
      archs.  This is a followup without any arch specific code.  Other than
      that there are no functional changes.]
    
    Some workloads that create a large number of small files tend to assign
    too many pages to node 0 (multi-node systems).  Part of the reason is
    that the rotor (in cpuset_mem_spread_node()) used to assign nodes starts
    at node 0 for newly created tasks.
    
    This patch changes the rotor to be initialized to a random node number
    of the cpuset.
    
    [akpm@linux-foundation.org: fix layout]
    [Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration]
    [mhocko@suse.cz: Make it arch independent]
    [akpm@linux-foundation.org: fix CONFIG_NUMA=y, MAX_NUMNODES>1 build]
    Signed-off-by: NJack Steiner <steiner@sgi.com>
    Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
    Signed-off-by: NMichal Hocko <mhocko@suse.cz>
    Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Cc: Christoph Lameter <cl@linux-foundation.org>
    Cc: Pekka Enberg <penberg@cs.helsinki.fi>
    Cc: Paul Menage <menage@google.com>
    Cc: Jack Steiner <steiner@sgi.com>
    Cc: Robin Holt <holt@sgi.com>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Christoph Lameter <cl@linux-foundation.org>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Jack Steiner <steiner@sgi.com>
    Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
    Cc: Michal Hocko <mhocko@suse.cz>
    Cc: Paul Menage <menage@google.com>
    Cc: Pekka Enberg <penberg@cs.helsinki.fi>
    Cc: Robin Holt <holt@sgi.com>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    778d3b0f
bitmap.c 34.5 KB