On Tue, 2017-03-28 at 16:25 +1100, Alexey Kardashevskiy wrote: > The CMA pages migration code does not support compound pages at > the moment so it performs few tests before proceeding to actual page > migration. > > One of the tests - PageTransHuge() - has VM_BUG_ON_PAGE(PageTail()) as > it should be called on head pages. Since we also test for PageCompound(), > and it contains PageTail(), we can simply move PageCompound() in front > of PageTransHuge() and therefore avoid possible VM_BUG_ON_PAGE. > > Signed-off-by: Alexey Kardashevskiy <[email protected]> > ---
The fix looks reasonable to me. I suspect the checks can be simplified and we can support split and move of THP in the future. For now, looks good Acked-by: Balbir Singh <[email protected]>
