On Tue, Sep 15, 2020 at 05:03:49PM +0200, Oleg Nesterov wrote: > > - if (reuse_swap_page(vmf->page, &total_map_swapcount)) { > > It seems that nobody else calls reuse_swap_page() with total_map_swapcount != NULL. Seems correct. Though maybe we could postpone the cleanup later, until the fallouts of the cow rework settle (just in case we'd like to bring some mapcount logic back). Thanks, -- Peter Xu