Messages in this thread | | | Date | Mon, 20 Aug 2012 19:35:14 +0000 | From | Christoph Lameter <> | Subject | Re: [PATCH 2/5] mempolicy: Remove mempolicy sharing |
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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 <cl@linux.com>
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