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    SubjectRe: [PATCH 2/5] mempolicy: Remove mempolicy sharing
    On Mon, 20 Aug 2012, Mel Gorman wrote:

    > Ideally, the shared policy handling would be rewritten to either properly
    > handle COW of the policy structures or at least reference count MPOL_F_SHARED
    > based exclusively on information within the policy. However, this patch takes
    > the easier approach of disabling any policy sharing between VMAs. Each new
    > range allocated with sp_alloc will allocate a new policy, set the reference
    > count to 1 and drop the reference count of the old policy. This increases
    > the memory footprint but is not expected to be a major problem as mbind()
    > is unlikely to be used for fine-grained ranges. It is also inefficient
    > because it means we allocate a new policy even in cases where mbind_range()
    > could use the new_policy passed to it. However, it is more straight-forward
    > and the change should be invisible to the user.

    Hmmm. I dont like the additional memory use but this is definitely an
    issue that needs addressing.

    Reviewed-by: Christoph Lameter <>

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      Last update: 2012-08-20 22:21    [W:0.020 / U:107.292 seconds]
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