Re: [PATCH] mremap: skip page table lookup for non-faulted anonymousVMAs

[Andrea Arcangeli]

On Mon, Nov 07, 2011 at 12:21:35PM +0800, Nai Xia wrote:
> If an anonymous vma has not yet been faulted, move_page_tables() in move_vma()
> is not necessary for it.

I actually thought of adding that (in fact fork has it and it's more
likely to be beneficial for fork than for mremap I suspect), but this
adds a branch to the fast path for a case that shouldn't normally
materialize. So I don't think it's worth adding it as I expect it to
add overhead in average.
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