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    hugetlb: fix get_policy for stacked shared memory files · 22741925
    Adam Litke 提交于
    Here's another breakage as a result of shared memory stacked files :(
    
    The NUMA policy for a VMA is determined by checking the following (in the
    order given):
    
    1) vma->vm_ops->get_policy() (if defined)
    2) vma->vm_policy (if defined)
    3) task->mempolicy (if defined)
    4) Fall back to default_policy
    
    By switching to stacked files for shared memory, get_policy() is now always
    set to shm_get_policy which is a wrapper function.  This causes us to stop
    at step 1, which yields NULL for hugetlb instead of task->mempolicy which
    was the previous (and correct) result.
    
    This patch modifies the shm_get_policy() wrapper to maintain steps 1-3 for
    the wrapped vm_ops.
    
    (akpm: the refcounting of mempolicies is busted and this patch does nothing to
    improve it)
    Signed-off-by: NAdam Litke <agl@us.ibm.com>
    Acked-by: NWilliam Irwin <bill.irwin@oracle.com>
    Cc: dean gaudet <dean@arctic.org>
    Cc: Christoph Lameter <clameter@sgi.com>
    Cc: Andi Kleen <ak@suse.de>
    Cc: <stable@kernel.org>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    22741925
shm.c 25.9 KB