On Tue, Mar 07, 2017 at 06:17:47PM +0300, Kirill A. Shutemov wrote: > On Thu, Mar 02, 2017 at 03:39:19PM +0900, Minchan Kim wrote: > > try_to_munlock returns SWAP_MLOCK if the one of VMAs mapped > > the page has VM_LOCKED flag. In that time, VM set PG_mlocked to > > the page if the page is not pte-mapped THP which cannot be > > mlocked, either. > > > > With that, __munlock_isolated_page can use PageMlocked to check > > whether try_to_munlock is successful or not without relying on > > try_to_munlock's retval. It helps to make ttu/ttuo simple with > > upcoming patches. > > I *think* you're correct, but it took time to wrap my head around. > We basically rely on try_to_munlock() never caller for PTE-mapped THP. > And we don't at the moment. > > It worth adding something like > > VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page); > > into try_to_munlock().
Agree. > > Otherwise looks good to me. > > Will free adding my Acked-by once this nit is addressed. Thanks for the review this part, Kirill! > > -- > Kirill A. Shutemov > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majord...@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"d...@kvack.org";> em...@kvack.org </a>
